| 词或词组 | 中文 | 英文解释中文解释 |
|---|---|---|
| Shell hardening | 壳型硬化 |
A surface-hardening process in which a suitable steel workpiece, when heated through and quench hardened, develops a martensitic layer or shell that closely follows the contour of the piece and surrounds a core of essentially pearlitic transformation product. This result is accomplished by a proper balance among section size, steel hardenability, and severity of quench. 一种表面硬化工艺，在该工艺中，合适的钢工件在加热和淬火硬化后，会形成一层马氏体层或壳，该层或壳紧随工件的轮廓，并包围一个基本上为珠光体相变产物的核心。这一结果通过截面尺寸、钢淬透性和淬火强度之间的适当平衡来实现。 |
| Structural analysis | 结构分析 |
The determination of the forces, displacements, stresses, and strains in a given structure. 确定给定结构中的力、位移、应力和应变。 |
| Coherent structure | 相干结构 |
A term given to the larger eddies of turbulent shear flow, such as boundary layers, jets, and wakes, that show distinctive correlated patterns of motion. 一个术语，用于表示湍流剪切流的较大涡流，例如边界层、射流和尾流，它们显示出独特的相关运动模式。 |
| Tangential load (Unit N) | 切向荷载（单位：N） |
The component of load applied to an object, such as a gear, that tends to cause or resist rotation. 旋转力施加在物体上的载荷分量，如齿轮，倾向于引起或阻止旋转。 |
| Meyer hardness (Unit Pa) | 迈耶硬度（单位Pa） |
A material hardness similar to the Brinell hardness but based upon the projected area of the impression rather than the surface area. 与布氏硬度相似的材料硬度，但基于印模的投影面积而不是表面面积。 |
| Celsius temperature scale | 摄氏温标 |
(centigrade temperature scale) A relative, non-SI, temperature scale now defined in terms of the Kelvin absolute temperature scale as °C = K − 273.15, where °C is the symbol for degrees Celsius. The scale was previously called the centigrade scale, with two fixed points: the melting point of ice (the ice point) as 0°C, and the boiling point of water (the steam point) as 100°C. （摄氏度温度标度）现在以开尔文绝对温度标度定义的相对非国际温度标度为°C=K-273.15，其中°C是摄氏度的符号。该刻度以前称为摄氏度刻度，有两个固定点：冰的熔点（冰点）为0°C，水的沸点（蒸汽点）为100°C。 |
| Specimen | 样品 |
A test object, often of standard dimensions or configuration, that is used for destructive or nondestructive testing. One or more specimens may be cut from each unit of a sample. 用于破坏性或无损检测的测试对象，通常具有标准尺寸或配置。可以从样品的每个单位切割一个或多个样品。 |
| Bolt blank | 螺栓毛坯 |
A rod on which a head has been formed, but on which no thread has been cut, from which bolts or screws may be made as required. 一种已形成头部但未切割螺纹的杆，可根据需要从中制造螺栓或螺钉。 |
| Oxidizing agent | 氧化剂 |
A compound that causes oxidation, thereby itself becoming reduced. 一种引起氧化从而自身被还原的化合物。 |
| Pressure-relief valve | 减压阀 |
A valve that limits the maximum pressure in a pressure vessel or fluid-power system to a specified level. 将压力容器或流体动力系统中的最大压力限制在规定水平的阀门。 |
| Stud | 螺柱 |
A rod having thread on both ends. A headless threaded fastener, threaded on both ends, with an unthreaded body in the middle section, or threaded from end to end. Used with two nuts, or with one nut and a tapped hole. A plain cylindrical piece having a threaded portion of suitable length at each end or a continuous thread over the entire length. One end is screwed into a machine or workpiece after which a second part is placed over the stud and held in place by a nut. 两端都有螺纹的杆。无头螺纹紧固件，两端有螺纹，中间部分有无螺纹主体，或从一端到另一端有螺纹。与两个螺母或一个螺母和一个螺纹孔一起使用。一种普通的圆柱形部件，其两端具有适当长度的螺纹部分，或在整个长度上具有连续螺纹。一端拧入机器或工件，然后将第二部分放在螺柱上，并用螺母固定到位。 |
| Elastic limit | 弹性极限 |
The maximum stress which a material is capable of sustaining without any permanent strain (deformation) remaining on complete release of the stress. 材料在完全释放应力时能够承受的最大应力，且不会留下任何永久应变（变形）。 |
| Izod test | 悬臂梁试验 |
A type of impact test in which a V-notched specimen, mounted vertically, is subjected to a sudden blow delivered by the weight at the end of a pendulum arm. The energy required to break off the free end is a measure of the impact strength or toughness of the material. 一种冲击试验，其中垂直安装的V形切口试样受到摆臂末端重量的突然冲击。断开自由端所需的能量是材料冲击强度或韧性的量度。 |
| Zero time | 零时 |
The time when the given loading or constraint conditions are initially obtained in creep or stressrelaxation tests, respectively. 分别在蠕变或应力松弛试验中初始获得给定载荷或约束条件的时间。 |
| V-belt | 三角带 |
A drive belt having a trapezoidal cross section which runs in pulleys with V-shaped grooves. Higher torques can be transmitted than with a flat belt. 一种具有梯形横截面的传动带，在带V形槽的皮带轮中运行。与平皮带相比，可以传递更高的扭矩。 |
| Hard temper | 硬化回火 |
Same as full hard temper. 和全硬化回火一样。 |
| Bearing test | 轴承测试 |
A method of determining the response to stress (load) of metal products that are subjected to riveting, bolting, or a similar fastening procedure. The purpose of the test is to determine the bearing strength of the material and to measure the bearing stress versus the deformation of the hole created by a pin or rod of circular cross section that pierces the sheet perpendicular to the surface. 一种确定经受铆接、螺栓连接或类似紧固程序的金属产品对应力（载荷）的响应的方法。测试的目的是确定材料的承载强度，并测量承载应力与由垂直于表面刺穿板材的圆形横截面的销或杆产生的孔的变形。 |
| Bypass ratio | 旁路比 |
In a turbofan engine, the ratio of the mass flow rate of the bypass stream to the mass flow rate through the core of the engine. 在涡扇发动机中，旁通流的质量流量与通过发动机核心的质量流量之比。 |
| Wing nut | 蝶形螺母 |
A nut having two opposite protruding wings to permit hand tightening. 一种螺母，有两个相对突出的翼片，可以用手拧紧。 |
| Normal temperature and pressure (NTP) | 常温常压（NTP） |
Reference conditions defined by NIST as 20°C and 1 atm. NIST定义的参考条件为20°C和1atm。 |
| Eccentric load | 偏心载荷 |
The external load on a fastener or groups of fasteners is said to be eccentric if the resultant of that load does not pass through the centroid of the group of fasteners (eccentric shear load ) or does not coincide with the bolt axis (eccentric tensile load ). 如果一个或多个紧固件上的外部载荷的合力未穿过紧固件组的质心（偏心剪切载荷）或与螺栓轴不重合（偏心拉伸载荷），则称该外部载荷为偏心。 |
| Fatigue notch factor (Kf) | 疲劳缺口系数（Kf） |
The ratio of the fatigue strength of an unnotched specimen to the fatigue strength of a notched specimen of the same material and condition; both strengths are determined at the same number of stress cycles. 无缺口试样的疲劳强度与相同材料和条件的有缺口试样的疲劳强度之比；两种强度都是在相同数量的应力循环下确定的。 |
| Austenite-stabilizer | 奥氏体稳定剂 |
Alloying element expanding the γ-phase field in the corresponding phase diagram, which manifests itself in a decrease of the A3 temperature and an increase of the A4 temperature in binary alloys Fe–M as well as in a decrease of A1 temperature in ternary alloys Fe–C–M (M is an alloying element). The solubility of austenite-stabilizers in ferrite is much lower than in austenite. Under the influence of austenite-stabilizers, austenite can become thermodynamically stable down to room temperature. 合金元素扩展了相应相图中的γ相场，这表现为二元合金Fe-M中A3温度的降低和A4温度的升高，以及A1温度的降低三元合金Fe–C–M（M是合金元素）。奥氏体稳定剂在铁素体中的溶解度远低于在奥氏体中的溶解度。在奥氏体稳定剂的影响下，奥氏体可以在低至室温时变得热力学稳定。 |
| Total elongation | 总伸长率 |
A total amount of permanent extension of a test piece broken in a tensile test. 拉伸试验中断裂试样的永久延伸总量。 |
| Thermal fatigue | 热疲劳 |
Fatigue resulting from the presence of temperature gradients that vary with time in such a manner as to produce cyclic stresses in a structure. 由于温度梯度的存在而产生的疲劳，温度梯度随时间变化，从而在结构中产生循环应力。 |
| Essential conditions | 必要条件 |
Each type of failure to which bolted joints are subject is set up by three or four conditions. The conditions vary, depending on the mode of failure, but never number more than four. Eliminating any one of the essential conditions for a particular type of failure can prevent that type of failure. 螺栓连接所遭受的每种类型的故障都由三个或四个条件确定。根据故障模式的不同，情况会有所不同，但数量不得超过四个。消除特定类型故障的任何一个基本条件都可以防止该类型故障。 |
| Fatigue life for p % survival | p%存活率的疲劳寿命 |
An estimate of the fatigue life that p% of the population would attain or exceed at a given stress level. The observed value of the median fatigue life estimates the fatigue life for 50% survival. Fatigue life for p% survival values, where p is any number, such as 95, 90, etc., may also be estimated from the individual fatigue life values. p%存活在给定应力水平下达到或超过的疲劳寿命估计值。中值疲劳寿命的观察值估计了50%存活率的疲劳寿命。p%存活值的疲劳寿命，其中p为任何数字，如95、90等，也可根据单个疲劳寿命值进行估算。 |
| U-bolt | U型螺栓 |
A rod threaded at both ends and bent into a U-shape. It is used for clamping. An externally threaded fastener bent in the shape of the letter U and with both ends threaded. 两端有螺纹并弯曲成U形的杆。用于夹紧。一种外螺纹紧固件，弯曲成字母U的形状，两端带有螺纹。 |
| Water quenching | 水淬 |
A quench in which water is the quenching medium. The major disadvantage of water quenching is its poor efficiency at the beginning or hot stage of the quenching process. 以水为淬火介质的淬火。水淬的主要缺点是在淬火过程的开始或热阶段效率低。 |
| Damage tolerance | 损伤容限 |
(defect tolerance) A design philosophy that takes into account initial imperfections, crack-growth rates and conditions at final fracture, and uses fracture mechanics to demonstrate that cracks should not grow to their critical length within the design life (or at least should be capable of ready detection). （缺陷公差）考虑初始缺陷、裂纹扩展速率和最终断裂条件的设计理念，并使用断裂力学证明裂纹不应在设计寿命内增长到其临界长度（或至少应能够随时检测）。 |
| Bearing strength | 承载强度 |
The maximum bearing stress that a material is capable of sustaining. 材料能够承受的最大承载应力。 |
| Fatigue crack growth rate (da/dN) | 疲劳裂纹扩展率（da/dN） |
The rate of crack extension caused by constant-amplitude fatigue loading, expressed in terms of crack extension per cycle of load application. 恒幅疲劳荷载引起的裂纹扩展速率，以每次荷载施加循环的裂纹扩展表示。 |
| Acceleration-error constant | 加速度误差常数 |
When the reference (demand) input to a control system is parabolic, the output signal will also be parabolic in steady state. The signal that is constant in this situation is the acceleration and thus for a parabolic input the steady-state error, referred to as the acceleration-error constant, is the error in the acceleration. 当控制系统的参考（需求）输入是抛物线时，输出信号在稳定状态下也将是抛物线。在这种情况下恒定的信号是加速度，因此对于抛物线输入，称为加速度误差常数的稳态误差是加速度中的误差。 |
| Coalescence | 聚结 |
Growth of grains at the expense of the remainder by absorption or the growth of a phase or particle at the expense of the remainder by absorption or reprecipitation. 通过吸收以牺牲剩余为代价的晶粒的生长或以通过吸收或再沉淀为代价的以剩余为代价的相或颗粒的生长。 |
| Dynamic load rating (Unit N) | 额定动载荷（单位N） |
The allowable load on a component or structure when the loading is not static. 当负载不是静态时，组件或结构上的允许负载。 |
| Corrosion failure | 腐蚀失效 |
1. The failure of a component or structure after corrosion has reduced the load-bearing area to an unsupportable level. 2. A situation in which a mechanism cannot function owing to corrosion products preventing free movement at joints. 1、部件或结构在腐蚀后失效，使承重面积减少到无法支撑的程度。2.由于腐蚀产物阻止关节处的自由运动，导致机构无法运行的情况。 |
| Angle of torsion | 扭转角 |
(angle of twist) (Unit ° or rad) The angle relative to a chosen section, normal to the axis of twist, through which another part of a component rotates when subjected to a torque. （扭转角）（单位°或弧度）相对于选定截面的角度，垂直于扭转轴，部件的另一部分在受到扭矩时通过该角度旋转。 |
| Thermal insulation (insulation) | 隔热（绝缘） |
A material that may be a low-conductivity solid, or a porous solid or fabric in which there are voids containing air or another gas, resulting in overall low thermal conductivity. When applied to the surface of a hot or cold object, surface heat transfer is generally reduced. 一种材料，可以是低导电性固体，或多孔固体或织物，其中存在含有空气或其他气体的空隙，从而导致整体低导热性。当应用于热或冷物体的表面时，表面传热通常减少。 |
| Working fluid | 工作流体 |
In thermodynamics, the fluid contained within the boundary of a system that experiences changes in its properties during any fluid dynamic or thermodynamic process. 在热力学中，包含在系统边界内的流体，在任何流体动力学或热力学过程中其性质发生变化。 |
| Bioengineering | 生物工程 |
(biological engineering) The application of engineering principles to biology, medicine, agriculture, etc. （生物工程）工程原理在生物学、医学、农业等方面的应用。 |
| Stress ratio (A or R) | 应力比（A或R） |
The algebraic ratio of two specified stress values in a stress cycle. Two commonly used stress ratios are the ratio of the alternating stress amplitude to the mean stress, A = Sa/Sm, and the ratio of the minimum stress to the maximum stress, R = Smin/Smax. 应力循环中两个指定应力值的代数比。两种常用的应力比是交变应力振幅与平均应力之比，A=Sa/Sm，以及最小应力与最大应力之比R=Smin/Smax。 |
| Athermal transformation | 非热变化 |
A reaction that proceeds without benefit of thermal fluctuations; that is, thermal activation is not required. In contrast, a reaction that occurs at constant temperature is an isothermal transformation; thermal activation is necessary in this case and the reaction proceeds as a function of time. 在没有热波动的情况下进行的反应；也就是说，不需要热激活。相反，在恒温下发生的反应是等温转变。在这种情况下，热活化是必要的，并且反应作为时间的函数进行。 |
| Ductile fracture | 韧性断裂 |
Fracture characterized by tearing of metal accompanied by appreciable gross plastic deformation and expenditure of considerable energy. A fracture of a component or structure which is preceded by extensive ductile deformation so that the broken pieces cannot be re-fitted to regain the original size and shape of the component or structure. 以金属撕裂为特征的断裂，伴随着明显的总塑性变形和相当大的能量消耗。一种部件或结构的断裂，在断裂前会发生大范围的延性变形，从而使断裂的碎片无法重新装配以恢复部件或结构原来的尺寸和形状。 |
| Pneumatic control valve | 气动控制阀 |
(pneumatic valve) A valve in which the position of the valve stem, which varies the open area, is determined by the net force generated by compressed air acting on a diaphragm operating against the force of a compression spring. Depending upon the arrangement of the spring, in the event of air-supply failure, the valve may open or close. （气动阀）一种阀门，其中阀杆的位置随开口面积的变化而变化，由压缩空气作用在隔膜上产生的净力决定，隔膜克服压缩弹簧的力进行操作。根据弹簧的布置，在供气故障的情况下，阀门可以打开或关闭。 |
| Design load (Unit N) | 设计荷载（单位N） |
The greatest load that a component or structure is expected to experience under normal operating conditions. 部件或结构在正常运行条件下预期承受的最大负载。 |
| Stress corrosion cracking (SCC) | 应力腐蚀开裂（SCC） |
A common form of Stress cracking in which an Electrolyte encourages the growth of a crack in a highly stressed bolt. Only a tiny quantity of electrolyte need be present, at the tip or face of the crack. A time-dependent process in which a metallurgically susceptible material fractures prematurely under conditions of simultaneous corrosion and sustained loading at lower stress levels than would be required in the absence of a corrosive environment. Tensile stress is required at the metal surface and may be a residual stress resulting from heat treatment or fabrication of the metal or the result of external loading. Cracking may be intergranular or transgranular, depending on the combination of alloy and environment. 一种常见的应力开裂形式，其中电解液促使高应力螺栓中的裂纹扩展。在裂纹尖端或表面，只需存在少量电解质。一种随时间变化的过程，其中冶金敏感材料在同时腐蚀和持续加载的条件下过早断裂，其应力水平低于无腐蚀环境时的要求。在金属表面需要拉应力，拉应力可以是金属的热处理或制造或外部负载产生的残余应力。裂纹可能是沿晶开裂或穿晶开裂，这取决于合金和环境的组合。 |
| Progressive aging | 渐进时效 |
Aging by increasing the temperature in steps or continuously during the aging cycle. 通过在时效周期中逐步或连续升高温度进行增加时效。 |
| Shear joint | 剪切接头 |
A joint which is subjected primarily to loads acting more or less perpendicular to the axes of the bolts. 主要承受或多或少垂直于螺栓轴线的载荷的接头。 |
| Compression wave | 压缩波 |
(dilatation wave) In a fluid or a solid, a progressive wave or wavefront that compresses the medium through which it propagates. （膨胀波）在流体或固体中，压缩介质传播的行波或波前。 |
| Crest | 波峰 |
The highest point of a wave or of a screw thread. 波浪或螺纹的最高点。 |
| Shear strength | 抗剪强度 |
The maximum shear stress that a material is capable of sustaining. Shear strength is calculated from the maximum load during a shear or torsion test and is based on the original dimensions of the cross section of the specimen. 材料能够承受的最大剪切应力。抗剪强度根据剪切或扭转试验期间的最大载荷计算，并基于试样横截面的原始尺寸。 |
| Bulk density (Unit kg/m³) | 容重（单位kg/m³） |
The average density of a mass of granular or powdered material at ambient conditions. 在环境条件下大量粒状或粉状材料的平均密度。 |
| Heat capacity (C) (Unit J/K) | 热容量（C）（单位J/K） |
The energy required to raise the temperature of a body by 1K without change of phase. Heat capacity is an extensive thermodynamic property dependent on temperature and pressure. 在不发生相变的情况下将物体的温度提高1K所需的能量。热容量是一种广泛的热力学性质，取决于温度和压力。 |
| Axial load (Unit N) | 轴向载荷（单位N） |
In general, a tensile or compressive load directed along the axis of a component. Strictly the load should pass through the centroid of the cross section to avoid inducing bending moments and be perpendicular to the plane of the section. 通常，沿部件的轴定向的拉伸或压缩载荷。严格来说，载荷应通过横截面的质心以避免产生弯矩并垂直于横截面。 |
| Left hand screw | 左螺旋 |
One that screws into the mating part or advances when turned to the left or counter clockwise. 旋入配合部分或向左或逆时针旋转时前进的螺钉。 |
| Screw | 螺钉 |
Threaded fastener designed to be used in a tapped or untapped (e.g., wood screw) hole, but not with a nut. A fastener with a screw thread cut or rolled into its cylindrical or conical shank, intended either to cut its own thread (as in a wood screw) or engage in a threaded hole. A self-tapping screw (sheet-metal screw, tapping screw) has a sufficiently hard thread that it cuts an internal thread in thin sheet or a component made of soft material when driven into a hole in the sheet or component. The screw head is the part of a screw used to apply torque to the screw. Common screw-head designs are circular in cross section with a diametral slot or cross, or hexagonal and recessed with a cross or hexagon. A screw thread is one or more continuous helical grooves of uniform section along either the exterior surface (male thread) or the interior surface (female thread) of a cylindrical or conical body. The three-dimensional shape that results when the thread cross section is rotated and axially advanced along an axis is called a helicoid, the angle that the thread makes when projected on to the axis being called the angle of inclination. Threads are employed in fasteners such as bolts, nuts, and screws; location and measuring instruments; in power drives; in some electrical fittings (Edison thread); and on the ends of crankshafts to suppress oil leakage (thrower thread). Parallel threads are formed on cylinders; tapered threads on cones, typically with a taper rate of 1:16. A screw with a righthanded thread appears to move away from the observer when turned clockwise. All standard screws, bolts and nuts have right-hand threads, but left-handed threads are sometimes employed. The axial distance between corresponding points on adjacent threads is called the screw pitch or screw rate and, for a single continuous helical groove (a single-start thread), is the same as the change in axial distance (the lead) between a nut and the head of a bolt during one revolution, the number of thread forms per mm then being the reciprocal of the pitch. For the same screw diameter, coarse threads have fewer threads per mm than fine threads. A multiple-start screw thread (usually coarse, see later) consists of two or more identical threads running simultaneously along its axis so as to provide greater bearing area and greater velocity ratio. The starts are separated by 180° (double start), 120° (triple start), 90° (quadruple start) etc., depending upon the number of threads. Thus, in double-start threads, the lead is twice the pitch; and so on. The axial distance between corresponding points on two adjacent threads in a multiple start thread is called the divided pitch. The position on a screw thread where there is equal distance between the flanks on the solid part of the thread and in the space between the threads is the pitch point, the associated diameter of which is termed the pitch diameter. The basic nomenclature for threads, some of which is common with that for toothed gearing, is shown in the diagrams. A helix formed or cut on a cylindrical surface which may advance along the axis to the right or left. The helix may be single or multiple. 一种螺纹紧固件，设计用于攻丝或未攻丝（如木螺钉）孔，但不与螺母配合使用。其螺纹被切割或卷成圆柱形或锥形柄，用于切割自身螺纹（如木螺钉）或嵌入螺纹孔。自攻螺钉（钣金螺钉、自攻螺钉）具有足够硬的螺纹，当打入薄板或部件中的孔时，它会在薄板或软材料部件中切割内螺纹。螺钉头是螺钉的一部分，用于向螺钉施加扭矩。常见的螺钉头设计为横截面为圆形，带有直径槽或十字，或为六边形，并带有十字或六边形凹槽。螺纹是沿圆柱形或锥形体的外表面（外螺纹）或内表面（内螺纹）具有均匀截面的一个或多个连续螺旋槽。当螺纹横截面旋转并沿轴轴向前进时产生的三维形状称为螺旋面，螺纹投影到轴上时形成的角度称为倾角。螺纹用于紧固件，如螺栓、螺母和螺钉；定位和测量仪器；在动力驱动中；在一些电气配件中（爱迪生螺纹）；并安装在曲轴端部，以抑制漏油（抛掷器螺纹）。在圆柱体上形成平行螺纹；圆锥上的锥形螺纹，通常具有1:16的锥形率。当顺时针旋转时，具有右手螺纹的螺钉似乎会远离观察者。所有标准螺钉、螺栓和螺母都有右手螺纹，但有时使用左手螺纹。相邻螺纹上对应点之间的轴向距离称为螺距或螺纹率，对于单个连续螺旋槽（单个起始螺纹），与螺母和螺栓头之间的轴向间距（导程）在一周内的变化相同，每mm的螺纹形式数为螺距的倒数。对于相同的螺钉直径，粗螺纹的每毫米螺纹数少于细螺纹。多头螺纹（通常为粗螺纹，见下文）由两个或多个沿其轴线同时延伸的相同螺纹组成，以提供更大的承载面积和更大的速比。根据螺纹的数量，起点之间的间隔为180°（双起点）、120°（三起点）、90°（四起点）等。因此，在双起始螺纹中，导程是螺距的两倍；多起点螺纹中两个相邻螺纹上对应点之间的轴向距离称为分割螺距。螺纹上的位置，即螺纹实体部分的侧面和螺纹之间的空间之间的距离相等，即节点，其相关直径称为节径。图中显示了螺纹的基本术语，其中一些与齿轮传动的基本术语相同。在圆柱面上形成或切割的螺旋线，可沿轴线向右或向左前进。螺旋可以是单个或多个。 |
| Caustic cracking | 苛性开裂 |
A form of stress-corrosion cracking most frequently encountered in carbon steels or iron-chromiumnickel alloys that are exposed to concentrated hydroxide solutions at temperatures of 200 to 250 °C (400 to 480 °F). Also known as caustic embrittlement. 在200至250°C（400至480°F）的温度下暴露于浓氢氧化物溶液中的碳钢或铁铬镍合金中最常遇到的一种应力腐蚀开裂形式。也称为碱脆。 |
| Ratchet coupling | 棘轮联轴器 |
A joint employing a ratchet system between two shafts, so that not only does the driven shaft run in one direction only, but also the driven shaft can, if necessary, run more quickly than the driving shaft. 在两个轴之间采用棘轮系统的接头，这样不仅从动轴只能在一个方向上运行，而且在必要时，从动轴可以比驱动轴运行得更快。 |
| Screw area (Unit m²) | 螺丝面积（单位m²） |
The area of a circle described by the tips of a propeller. 螺旋桨尖端所描述的圆的面积。 |
| Thermochemical treatment | 热化学处理 |
Heat treatment carried out in a medium suitably chosen to produce a change in the chemical composition of the object by exchange with the medium. 在适当选择的介质中进行热处理，以通过与介质交换产生物体化学成分的变化。 |
| Coefficient of friction (μ) | 摩擦系数（μ） |
(coefficient of kinetic friction, coefficient of sliding friction, friction coefficient, μ) The ratio of the frictional force F to the normal force N between two surfaces in contact, i.e. μ = F/N. Static friction is when there is no relative sliding; kinetic friction when there is. For structural components sliding on one another, the coefficient of friction is the ratio of the force causing the sliding to the force perpendicular to the sliding component surfaces. The coefficient of friction is dimensionless with values between zero and one. The number characterising the force necessary to slide or roll one material along the€surface of another. If an object has a weight N and the coefficient of friction is μ, then the force F necessary to move it without acceleration along a level surface is F = μN. The coefficient of static friction determines the force necessary to initiate movement; the coefficient of kinetic friction determines the force necessary to maintain movement. Kinetic friction is usually smaller than static friction. （动摩擦系数、滑动摩擦系数、摩擦系数，μ）两个接触表面之间摩擦力F与法向力N的比值，即μ=F/N。静摩擦是指没有相对滑动时；有摩擦时的动摩擦。对于相互滑动的结构部件，摩擦系数是引起滑动的力与垂直于滑动部件表面的力的比值。摩擦系数是无量纲的，其值介于0和1之间。代表一种材料沿另一种材料的表面滑动或滚动所需的力的数字。如果一个物体的重量为N并且摩擦系数为μ，那么在没有加速度的情况下沿水平表面移动它所需的力F为F=μN。静摩擦系数决定了启动运动所需的力；动摩擦系数决定了保持运动所需的力。动摩擦通常小于静摩擦。两个物体之间的力（F）与将这些物体压在一起的法向力（N）的无量纲比：μ（或f）=（F/N）。 |
| Torsion-bar suspension | 扭杆悬架 |
A type of motor-vehicle suspension in which one end of a torsion bar is rigidly fixed to the chassis while the other carries a lever to which are attached the components that carry a wheel. In a torsion-beam suspension, a beam connects the wheels on either side of the vehicle. 一种汽车悬架，其中扭力杆的一端刚性固定在底盘上，而另一端带有一个杠杆，杠杆上连接着承载车轮的部件。在扭转梁悬架中，梁连接车辆两侧的车轮。 |
| Dimensioning | 尺寸标注 |
The specification on an engineering drawing of the size (e.g. length, radius, angle, or spacing) and the relative location (e.g. angular position) of each feature of a component. The numerical values often include the tolerances. There should be no more dimensions than are necessary to manufacture the component. 工程图纸上对部件每个特征的尺寸（例如长度、半径、角度或间距）和相对位置（例如角位置）的规范。数值通常包括公差。尺寸不应超过制造组件所需的尺寸。 |
| Degradation | 降解 |
The reduction with time of the physical properties of a material. 材料的物理性质随时间的减少。 |
| Quarter hard | （1/4H）低硬（回火） |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength aboutmidway between that of dead soft and half hard tempers. 非铁合金和某些铁合金的一种回火，其特点是抗拉强度介于软态和半硬态之间。 |
| Composite material | 复合材料 |
(composite structure) A general term used of two or more materials or structures acting in combination (e.g. concrete, reinforced concrete, filamentreinforced polymers, laminated materials, particulate-reinforced materials, flitched beams), resulting in values of strength, stiffness, or toughness greater than the base matrix material alone. （复合结构）用于组合作用的两种或多种材料或结构的通用术语（例如混凝土、钢筋混凝土、纤维增强聚合物、层压材料、颗粒增强材料、切割梁），从而产生强度、刚度或韧性值大于单独的基体材料。 |
| Uniaxial strain | 单轴应变 |
Increase (or decrease) in length resulting from a stress acting parallel to the longitudinal axis of the specimen. 由平行于试样纵轴的应力引起的长度增加（或减少）。 |
| Malleable cast iron | 可锻铸铁 |
A cast iron made by prolonged annealing of white cast iron in which decarburization or graphitization, or both, take place to eliminate some or all of the cementite. The graphite is in the form of temper carbon. If decarburization is the predominant reaction, the product will exhibit a light fracture surface, hence, “whiteheart malleable;” otherwise, the fracture surface will be dark, hence, “blackheart malleable.” Ferritic malleable has a predominantly ferritic matrix; pearlitic malleable may contain pearlitic, spheroidite or tempered martensite depending on heat treatment and desired hardness. 白口铸铁一种通过长时间退火制成的铸铁，脱碳，石墨化，或两者都发生，以消除部分或全部渗碳体。石墨是回火碳的形式。如果脱碳是主要反应，产品将呈现出较轻的断裂表面，“白心可锻”。否则，断裂表面将变暗，“黑心可锻”。铁素体可锻性材料主要为铁素体基体；根据热处理和所需硬度，珠光体可锻材料可能包含珠光体、球状体或回火马氏体。 |
| Reverse pitch (Unit °) | 反向螺距（单位°） |
The pitch of a variable-pitch propeller that produces negative thrust. 产生负推力的变桨距螺旋桨的桨距。 |
| Density | 密度 |
The mass per unit volume of a solid material. (mass density, ρ) (Unit kg/m³) The mass per unit volume of a substance that satisfies the continuum assumption. The reciprocal of specific volume. 固体材料每单位体积的质量。（质量密度，ρ）（单位kg/m³）满足连续统假设的物质每单位体积的质量。和比容相关联。 |
| Hysteresis | 滞后 |
The phenomenon of permanently absorbed or lost energy that occurs during any cycle of loading or unloading when a material is subjected to repeated loading. 当材料经受重复加载时，在任何加载或卸载循环期间发生的永久吸收或损失能量的现象。 |
| Air conditioning | 空调 |
The process of controlling the temperature and humidity in rooms, buildings, aircraft, passenger vehicles, etc. More generally it includes control of dust, levels of radiant heat, etc. 控制房间、建筑物、飞机、客运车辆等的温度和湿度的过程。更一般地说，它包括控制灰尘、辐射热水平等。 |
| Adhesive wear | 粘着磨损 |
Wear that develops when two surfaces slide across one another under pressure. The removal or displacement of material from a surface by the welding together and subsequent shearing of minute areas of two surfaces that slide across each other under pressure. In advanced stages, may lead to galling. Contrast with abrasive wear. 当两个表面在压力下相互滑动时产生的磨损。通过焊接在一起并随后剪切在压力下相互滑动的两个表面的微小区域，从表面去除或置换材料。在晚期，可能会导致擦伤。与磨料磨损形成对比。 |
| Crank angle (Unit °) | 曲柄角度（单位°） |
The angle between the crank of a slider-crank mechanism and a line from the crankshaft centreline to the piston axis. 曲柄滑块机构的曲柄与曲轴中心线到活塞轴线的直线之间的角度。 |
| Spring load (Unit N) | 弹簧载荷（单位：N） |
A load exerted on a component by bending, compressing, extending, or twisting an attached spring. Mechanical energy stored in the spring can be released if any constraints on the component are removed. 通过弯曲、压缩、延伸或扭转连接的弹簧而施加在部件上的载荷。如果部件上的任何约束被移除，则可以释放弹簧中存储的机械能。 |
| Peel strength (Unit N) | 剥离强度（单位：N） |
(peel test) The strength of an adhesive bond between two materials as measured by the force required in a given direction to peel apart adhered strips. This force depends on the dimensions and thickness of the adhered strips and their yield stress, together with the fracture toughness of the bond. （剥离试验）两种材料之间的粘合强度，通过给定方向上剥离粘合条所需的力来测量。该力取决于粘合条的尺寸和厚度及其屈服应力，以及粘合剂的断裂韧性。 |
| Effective discharge area (Unit m²) | 有效排放面积（单位m²） |
A nominal area for flow through a pressure relief valve used to determine the valve’s flow capacity given the pressure difference across it, the fluid density and correction factors to allow for compressibility, the back pressure and the coefficient of discharge. 流经泄压阀的标称面积，用于确定阀门的流量，给定压力差、流体密度和允许可压缩性的校正因子、背压和排放系数。 |
| Batch | 一批 |
A definite quantity of some product or material produced under conditions that are considered uniform. A batch is usually smaller than a lot. 在被认为是均匀的条件下生产的一定数量的某些产品或材料。批次通常小于很多。 |
| Tooth lock washers | 带齿锁紧垫圈 |
These washers serve to lock fasteners, such as bolts and nuts, to the component parts of an assembly, or increase the friction between the fasteners and the assembly. They are designated in a manner similar to helical spring lock washers, and are available in carbon steel. 这些垫圈用于将紧固件（如螺栓和螺母）锁定到组件的零部件上，或增加紧固件与组件之间的摩擦力。它们的设计方式类似于螺旋弹簧锁紧垫圈，可采用碳钢。 |
| Granular fracture | 粒状断裂 |
A type of irregular surface produced when metal is broken that is characterized by a rough, grainlike appearance, rather than a smooth or fibrous one. It can be subclassified as transgranular or intergranular. 金属破碎时产生的一种不规则表面，其特征是粗糙的颗粒状外观，而不是光滑或纤维状的外观。它可以细分为穿晶或晶间。 |
| Fahrenheit | 华氏度 |
The temperature scale based on the freezing point of water (32ºF) and the boiling point of water (212ºF). The interval between these points is divided into 180 equal parts. Although replaced by the Celsius scale, the Fahrenheit scale is still sometimes used for non-scientific measurements. 温标基于水的冰点（32ºF）和水的沸点（212ºF）。这些点之间的间隔被分成180等份。尽管被摄氏刻度所取代，华氏刻度有时仍用于非科学测量。 |
| Friction loss (Unit J) | 摩擦损失（单位J） |
The conversion of mechanical energy to heat due to friction within a machine, mechanism, linkage, etc. 由于机器、机构、连杆等内部的摩擦而将机械能转化为热能。 |
| Corrosion fatigue | 腐蚀疲劳 |
Cracking produced by the combined action of repeated or fluctuating stress and a corrosive environment at lower stress levels or fewer cycles than would be required in the absence of a corrosive environment. 由重复或波动的应力和腐蚀环境的联合作用产生的开裂，其应力水平低于没有腐蚀环境时所需的应力水平或循环次数更少。 |
| Cohesive strength | 内聚强度 |
(Unit Pa) A theoretical fracture strength for solids based on interatomic forces, approximately equal to E/10 where E is Young’s modulus. （单位Pa）基于原子间力的固体理论断裂强度，大约等于E/10，其中E是杨氏模量。 |
| Knot (kn) | 节（kn） |
A non-SI unit defined as one nautical mile per hour. The conversion to SI is 1 kn = 5.144 444 444×10−1 m/s. 非国际单位制单位，定义为每小时一海里。转换为SI为1kN=5.144444×10−1米/秒。 |
| Surface hardness | 表面硬度 |
(superficial hardness) Indentation hardness on, and for some distance below, the surface of a component, as opposed to its bulk hardness. Depending on the resolution required, micro- or nano-hardness testing machines are employed. （表面硬度）与整体硬度相反，部件表面及其下方一定距离的压痕硬度。根据所需的分辨率，可使用微型或纳米硬度测试机。 |
| Quick coupling | 快速接头 |
(quick disconnect, fast coupling) A hose connection allowing rapid assembly or disassembly and comprising a socket and a plug incorporating a springloaded locking mechanism. （快速断开、快速连接）一种软管连接，允许快速组装或拆卸，包括插座和带有弹簧加载锁定机构的插头。 |
| Stress amplitude | 应力幅值 |
One-half the algebraic difference between the maximum and minimum stress in one cycle of a repetitively varying stress. 重复变化应力的一个循环中最大和最小应力之间代数差的一半。 |
| Tension | 拉伸 |
The force or load that produces elongation. 1. The condition in a bar, belt, cable, spring, string, wire, etc. that is being pulled from either end. 2. (tensile force) (unit N) The force associated with tension as in (1). It is measured by a tension meter. 伸长力产生伸长的力或载荷。1.从两端拉出的杆、带、电缆、弹簧、线、线等的状态。2.（张力）（单位N）与张力相关的力。 |
| Water jacket | 水套 |
A casing, typically of sheet metal, surrounding a machine, such as an engine, that requires cooling. Water is circulated through the jacket and a heat exchanger where the heat is removed. 机壳一种机壳，通常由金属板制成，围绕着需要冷却的机器，如发动机。水通过夹套和热交换器循环，在热交换器中热量被去除。 |
| Forge | 锻造 |
To shape metal while holt and plastic by a hammering or forcing process. Dies used in process. 通过锤击或强制过程使金属成型，同时保持塑料成型。过程会使用模具。 |
| Tightness, acceptable | 密封性，可接受的 |
Wholly leak-free joints are impossible, at least if the contained fluid is a gas, so it has been proposed that the design of a gasketed joint should start with the selection of an ‘‘acceptable’’ leak rate. The designer would dimension bolts and joint members so that the actual leak rate would never exceed this. Three standard levels of tightness have been proposed as well. 至少在所含流体为气体的情况下，完全无泄漏的接头是不可能的，因此有人建议，垫圈接头的设计应从选择“可接受”的泄漏率开始。设计师将确定螺栓和接头构件的尺寸，以便实际泄漏率永远不会超过此值。还提出了三种标准的密封性等级。 |
| Surface roughness (roughness) | 表面粗糙度 |
The small-scale, irregular peaks and troughs in a solid surface which are quantified using a surface analyser. Roughness may be a consequence of wear and corrosion, or of the manufacturing process. It leads to increased friction in solid– solid contact or fluid flow over a surface. Errors of form and waviness are excluded, but surface texture includes roughness and waviness. Surface topography incorporates the small-scale, three-dimensional geometry of a surface including surface roughness, machined, and etched features, typically at sub-mm scales. 固体表面中的小尺度不规则峰谷，使用表面分析仪进行量化。粗糙度可能是磨损和腐蚀或制造过程的结果。它会导致表面上的固-固接触或流体流动中的摩擦增加。不包括形状和波纹度误差，但表面纹理包括粗糙度和波纹度。表面形貌包括表面的小尺度三维几何结构，包括表面粗糙度、机加工和蚀刻特征，通常为亚毫米尺度。 |
| Electrode | 电极 |
The two metallic bodies in a battery or Corrosion cell which give up electrons (the Anode) or which attract them (the Cathode). 电池或腐蚀电池中释放电子（阳极）或吸引电子（阴极）的两个金属体。 |
| Mole (mol) | 摩尔（mol） |
The base unit of the amount of substance in the SI system. It was previously defined as the amount of substance of a system that contains as many elementary entities as there are atoms in 0.012 kg of carbon-12. From 20 May 2019 it has been defined as the amount of substance containing exactly 6.022 140 76 × 1023 elementary entities. SI国际单位制中物质量的基本单位。此前，它被定义为一个系统中的物质量，该系统包含的基本实体数量与0.012千克碳-12中的原子数量相同。从2019年5月20日起，它已被定义为包含6.02214076×1023个基本实体的物质量。 |
| Permissible variation | 允许偏差 |
For testing machines, the maximum allowable error in the value of the quantity indicated. It is convenient to express permissible variation in terms of the percent error. 对于试验机，所示数量值的最大允许误差。用误差百分比表示允许偏差是很方便的。 |
| Absorptance | 吸收率 |
(absorptivity, absorption coefficient, α) The fraction of radiant flux incident on a surface that is absorbed by the surface. The term also applies to absorption of radiation by a volume of fluid. For a semi-transparent surface, α + ρ + τ = 1, where ρ is the reflectance and τ is the transmittance. （吸收率，吸收系数，α）入射到表面的辐射通量被表面吸收的部分。该术语也适用于一定体积的流体对辐射的吸收。对于半透明表面，α+ρ+τ=1，其中ρ是反射率，τ是透射率。 |
| Fastener testing | 紧固件测试 |
A determination or verification that the fastener meets its specification requirements. 确定或验证紧固件符合其规范要求。 |
| Blue annealing | 蓝色退火 |
Heating hot-rolled ferrous sheet in an open furnace to a temperature within the transformation range and then cooling in air, in order to soften the metal. The formation of a bluish oxide on the surface is incidental. 在开放式炉中将热轧铁板加热到转变范围内的温度，然后在空气中冷却，以软化金属。在表面上形成蓝色氧化物是偶然的。 |
| Temper | 回火 |
(1) In heat treatment, reheating hardened steel or hardened cast iron to some temperature below the eutectoid temperature for the purpose of decreasing hardness and increasing toughness. The process also is sometimes applied to normalized steel. (2) In tool steels, temper is sometimes used, but inadvisedly, to denote the carbon content. (3) In nonferrous alloys and in some ferrous alloys (steels that cannot be hardened by heat treatment), the hardness and strength produced by mechanical or thermal treatment, or both, and characterized by a certain structure, mechanical properties, or reduction in area during cold working. （1）在热处理中，将硬化钢或硬化铸铁重新加热到共析温度以下的温度，以降低硬度和增加韧性。该工艺有时也适用于正火钢。（2）在工具钢中，有时使用回火来表示碳含量，但这是不恰当的。（3）在非铁合金和一些铁合金（不能通过热处理硬化的钢）中，通过机械或热处理或两者产生的硬度和强度，其特征是在冷加工过程中具有一定的结构、机械性能或面积减小。 |
| Dead centre | 止点 |
The point at which, in a crank mechanism, the piston connecting rod and crank are all in line so that there can be no driving moment. 在曲柄机构中，活塞连杆和曲柄都在一条线上，因此不会有驱动力矩。 |
| Mode of failure | 故障模式 |
The various ways in which a material can fail when subjected to loading, surface damage, chemical attack, heating, cooling, or radiation, in either isolation or combination. The failure modes include fracture, fatigue, creep, corrosion, erosion, and embrittlement. 材料在受到载荷、表面损伤、化学侵蚀、加热、冷却或辐射时，可能发生失效的各种方式，无论是单独还是组合。失效模式包括断裂、疲劳、蠕变、腐蚀、侵蚀和脆化。 |
| Forced-air quench | 强制空气淬火 |
A quench utilizing blasts of compressed air against relatively small parts such as a gear. 利用压缩空气冲击相对较小的零件（例如齿轮）进行的淬火。 |
| Machine | 机器 |
A mechanism that transmits power in the performance of a useful task. More than one machine in one place, either connected or performing separate functions, is termed machinery. 在执行有用任务时传递能量的机制。一个地方有一台以上的连接或执行单独的功能，称为机器。 |
| Creep fatigue | 蠕变疲劳 |
The effects of combined creep and fatigue at high homologous temperatures in metals, and in other materials such as polymers having time-dependent behaviour. 金属和其他材料（例如具有时间相关行为的聚合物）在高同源温度下的组合蠕变和疲劳的影响。 |
| Stress | 应力（单位Pa） |
The intensity of the internally distributed forces or components of forces that resist a change in the volume or shape of a material that is or has been subjected to external forces. Stress is expressed in force per unit area and is calculated on the basis of the original dimensions of the cross section of the specimen. Stress can be either direct (tension or compression)or shear. 1. Stress ‘at a point’ (i.e. over a volume of material that is very small compared with that of the component or structure) is the load per unit area for every face of an infinitesimal cube surrounding the point. 2. In fluid flow the stress tensor σij is the sum of an isotropic part −pδij, δij being the Kronecker delta, having the same form as the stress tensor for a fluid at rest, p being the static pressure, and the non-isotropic, deviatoric stress tensor dij which is due entirely to the fluid motion. 内部分布力或力分量的强度，这些力或力的分量抵抗正在或已经受到外力的材料的体积或形状的变化。应力以单位面积的力表示，并根据试样横截面的原始尺寸计算。应力可以是直接（拉伸或压缩）或剪切。1.“在一点”的应力（即在与组件或结构相比非常小的材料体积上）是围绕该点的无限小立方体的每个面的单位面积载荷。2. 在流体流动中，应力张量σij是各向同性部分-pδij的总和，δij是Kroneckerδ，具有与静止流体的应力张量相同的形式，p是静压，非各向同性, 偏应力张量 dij 完全由流体运动引起。 |
| Dew point analyzer | 露点分析仪 |
An atmosphere monitoring device that measures the partial pressure of water vapor in an atmosphere. 一种大气监测装置，用于测量大气中水蒸气的分压。 |
| Transformation temperature | 相变温度 |
The temperature at which a change in phase occurs. The term is sometimes used to denote the limiting temperature of a transformation range. The following symbols are used for iron and steels. 发生相位变化的温度。该术语有时用于表示转变范围的极限温度。以下符号用于钢铁。 |
| Graphitizing | 石墨化退火 |
Annealing a ferrous alloy in such a way that some or all of the carbon is precipitated as graphite. 以使部分或全部碳以石墨的形式沉淀的方式对铁合金进行退火。 |
| Materials selection | 材料选择 |
The process of selecting the most suitable material for a particular application. In the case of solid materials, it involves assessment of candidate materials in terms of their physical properties (density, elastic moduli, fracture toughness, yield strength, hardness, fatigue resistance, coefficient of thermal expansion, thermal conductivity, resistance to thermal shock, creep resistance, corrosion resistance, radiation resistance, etc), and such factors as the function of the final product, its shape, method of manufacture, required tolerances, number to be made, ease of inspection and quality control, cost, and design methodology employed. 为特定应用选择最合适材料的过程。对于固体材料，它涉及根据其物理特性（密度、弹性模量、断裂韧性、屈服强度、硬度、抗疲劳性、热膨胀系数、导热系数、抗热冲击性、抗蠕变性、耐腐蚀性、抗辐射性等）评估候选材料，以及诸如最终产品的功能、其形状、制造方法、所需公差、制造数量、检查和质量控制的容易程度、成本和采用的设计方法等因素。 |
| Helical spring | 螺旋弹簧 |
A spring manufactured by forming elastic wire into a helix which may be cylindrical, conical, barrel-shaped, or hourglass in overall form. Closed-coiled springs are used in tension; open-coiled in both tension and compression. 一种弹簧，通过将弹性线材制成螺旋形而制成，螺旋形的整体形状可以是圆柱形、圆锥形、桶形或沙漏形。拉力采用闭合盘簧；在拉伸和压缩中都开卷。 |
| Nut splitter | 螺母分离器 |
A tool for removing rusted-on and corroded nuts from bolts. It consists of a stiff steel ring that is placed around the nut. A screw thread passing through the ring bears diametrically on a wedged-shape tip that indents and cuts though a face of the nut. 从螺栓上去除锈蚀螺母的工具。它由一个围绕螺母放置的刚性钢环组成。穿过环的螺纹径向支撑在楔形尖端上，该尖端凹陷并穿过螺母的表面。 |
| Turning angle (θ) | 转向角（θ） |
The change in direction experienced by a gas flow passing through an oblique shock wave or Prandtl–Meyer expansion fan. 气流通过斜激波或Prandtl–Meyer膨胀风机时所经历的方向变化。 |
| Collar | 圈、箍 |
A ring secured to, or integral with, a shaft to give axial location. 固定在轴上或与轴成一体以提供轴向位置的环。 |
| Zirconia-toughened alumina composites | 氧化锆增韧氧化铝复合材料 |
(ZTA composites) Ceramic composites based on aluminium oxide to which zirconium oxide is added, resulting in improved fracture toughness. （ZTA复合材料）基于氧化铝的陶瓷复合材料，其中添加了氧化锆，从而提高了断裂韧性。 |
| Brake lining | 制动衬片 |
The replaceable friction material that covers a brake shoe in an internally expanding brake. 在内膨胀制动器中覆盖制动的可更换摩擦材料。 |
| Serrations | 锯齿 |
A row of notches or tooth-like projections on an edge or surface. On an engineering drawing, serrations on the surface of a circular component are shown over about 60° of arc. 边缘或表面上的一排凹口或齿状突起。在工程图纸上，圆形部件表面的锯齿超过约60°的圆弧。 |
| DIN | DIN |
Deutsches Institut für Normung, the German Institute for Standardization. Deutsches Institut für Normung，德国标准化研究所。 |
| Breaking stress | 断裂应力 |
The stress at failure. Also known as rupture stress. 失效时的应力。也称为破裂应力。 |
| Carbon potential | 碳势 |
A measure of the ability of an environment containing active carbon to alter or maintain, under prescribed conditions, the carbon level of the steel. Note: In any particular environment, the carbon level attained will depend on such factors as temperature, time, and steel composition. 衡量含有活性碳的环境在规定条件下改变或保持钢的碳含量的能力。注意：在任何特定环境中，所达到的碳含量将取决于温度、时间和钢成分等因素。 |
| Starting taper | 起始锥度 |
The taper on the end of a reamer or tap which aids in starting the cut. 铰刀或丝锥端部的锥度，有助于开始切割。 |
| Shrink ring | 预紧环 |
A ring, which is expanded by heating, is placed around an assembly of parts, and then contracts upon cooling to hold the assembly in place. 通过加热膨胀的环被放置在零件组件周围，然后在冷却时收缩以将组件固定到位。 |
| Kilogram (kg) | 千克（kg） |
The base unit of mass in the SI system. It was previously defined as being equal to the mass of the International Prototype Kilogram, a right cylinder of height and diameter 39.17 mm made of an alloy of 90% (by mass) platinum and 10% iridium. From 20 May 2019 it has been defined by taking the fixed numerical value of the Planck constant h to be 6.626 070 150 × 10−34 when expressed in the unit J.s, which is equal to kg.m².s. 国际单位制中的基本质量单位。它以前被定义为等于国际原型千克的质量，一个高度和直径为39.17毫米的右圆柱体，由90%（质量）的铂和10%的铱合金制成。从2019年5月20日起，普朗克常数h的固定数值被定义为6.626070150×10−34当以单位J.s表示时，和kg.m².s一样。 |
| Screw compressor | 螺杆压缩机 |
A positive-displacement rotary compressor in which gas is progressively compressed by two intermeshing, counter-rotating, helical screws. 一种容积式旋转压缩机，其中气体由两个相互啮合、反向旋转的螺旋螺杆逐渐压缩。 |
| Constant life diagram | 恒定寿命图 |
A plot of experimentally derived fatigue-life data; perhaps the most complex and complete of the popular charts used to represent such data. 实验得出的疲劳寿命数据图；可能是用于表示此类数据的最复杂和最完整的流行图表。 |
| Joule | 焦耳 |
The SI unit of energy. One joule is the work done by a force of one newton acting over a distance of one metre. The symbol is J, where 1 J = 1 N m. 国际单位制能量单位。一焦耳是一牛顿的力在一米的距离上所做的功。符号为J，其中1j=1m。 |
| Hydrogen damage | 氢损伤 |
A general term for the embrittlement, cracking, blistering, and hydride formation that can occur when hydrogen is present in some metals. 当氢存在于某些金属中时可能发生的脆化、开裂、起泡和氢化物形成的总称。 |
| Thermal compressor | 热压缩机 |
1. (thermocompressor) A jet compressor used to boost the pressure of low-pressure waste or exhaust steam. 2. A device consisting of an absorber, a generator, a pump, and a throttling device, used instead of a mechanical vapour compressor in an absorption-cooling refrigeration system. 1.（热压缩机）用于提升低压废蒸汽或排气压力的喷射压缩机。2.一种由吸收器、发电机、泵和节流装置组成的装置，用于替代吸收冷却制冷系统中的机械蒸汽压缩机。 |
| Coextrusion | 复合挤压 |
The simultaneous extrusion through the same die of two or more materials in combination. 通过同一模具同时挤出两种或多种材料的组合。 |
| Heat-capacity ratio (c*) | 热容量比（c*） |
A non-dimensional parameter that arises in the analysis of heat exchangers, defined as the ratio cMIN/cMAX where cMIN is the heat-capacity rate c for the fluid with the smaller value of c and cMAX the value for the fluid with the larger value of c. Different flow rates and specific-heat values give rise to different values for c. 热交换器分析中出现的无量纲参数，定义为比率cMIN/cMAX其中cMIN是流体的热容率c，c值较小，cMAX是流体的值具有较大的c值。不同的流速和比热值产生不同的c值。 |
| Wrist | 腕关节 |
The final three joints on a robot which simulate rotations provided by the human wrist and thus allow orientation of the end effector to which it is attached by the wrist socket. 机器人上的最后三个关节，模拟人类手腕提供的旋转，从而允许其通过手腕插座连接到的末端执行器的方向。 |
| Conditioning heat treatment | 调质热处理 |
A preliminary heat treatment used to prepare a material for desired reaction to a subsequent heat treatment. For the term to be meaningful, the exact heat treatment must be specified. 用于制备材料的初步热处理，以便对随后的热处理进行所需的反应。为了使该术语有意义，必须指定确切的热处理。 |
| Stress area | 应力面积 |
The effective cross-sectional area of the threaded section of a fastener. Used to compute average stress levels in that section. Based on the mean of pitch and minor diameters. 紧固件螺纹部分的有效横截面积。用于计算该截面中的平均应力水平。基于节距和小直径的平均值。 |
| Self-loosening | 自松动 |
The process by which a supposedly tightened fastener becomes loose, as a result of vibration, thermal cycles, shock, or anything else which cause transverse slip between joint members and between male and female threads. Vibration loosening is a common, but special, case of self-loosening. 由于振动、热循环、冲击或任何其他导致接头构件之间以及阳螺纹和阴螺纹之间横向滑动的原因，紧固件松动的过程。振动松动是自松动的一种常见但特殊的情况。 |
| Gauge pressure (Unit Pa) | 表压（单位Pa） |
The level of static pressure above the ambient pressure. 高于环境压力的静压水平。 |
| Safety valve (safety-relief valve) | 安全阀（安全泄压阀） |
A mechanical valve, fitted by law to all pressure vessels (e.g. steam boilers), which opens to prevent the internal pressure exceeding the maximum design value for that vessel. The valve closes again once the pressure reduces to a safe level. 根据法律安装在所有压力容器（如蒸汽锅炉）上的机械阀，其打开以防止内部压力超过该容器的最大设计值。一旦压力降至安全水平，阀门将再次关闭。 |
| Active accommodation | 主动适应能力 |
The use of information from sensors, for example, in a vision system, that allows a robot to show accommodation to the environment. 使用来自传感器的信息，例如在视觉系统中，允许机器人显示对环境的适应。 |
| Austenitic grain size | 奥氏体晶粒尺寸 |
The size attained by the grains of steel when heated to the austenitic region; may be revealed by appropriate etching of cross sections after cooling to room temperature. 当加热到奥氏体区域时钢晶粒达到的尺寸；冷却至室温后，可通过适当蚀刻横截面来显示。 |
| Fastener manufacturer | 紧固件制造商 |
An organization that fabricates raw steel into a fastener meeting specified standards. 将生钢加工成符合规定标准的紧固件的组织。 |
| Double-shear test | 双剪试验 |
A shear test having two stationary, shear blades and one moving one and that uses solid round bars as test specimens. 一种剪切试验，具有两个固定的剪切刀片和一个移动的刀片，并使用实心圆棒作为试样。 |
| Cleavage fracture | 解理断裂 |
A fracture, usually of a polycrystalline metal, in which most of the grains have failed by cleavage, resulting in bright reflecting facets. It is one type of crystalline fracture and is associated with low energy brittle fracture. Contrast with shear fracture. A fracture created by splitting (cleavage), as between layers in materials like slate or mica. In brittle metals, and brittle microconstituents in alloys, cleavage occurs along particular crystal planes. 一种通过分裂（劈裂）产生的裂缝断裂，通常是多晶金属的断裂，其中大部分晶粒因解理而失效，产生明亮的反射面。它是一种结晶性断裂，与低能脆性断裂有关。与剪切断裂相对。如板岩或云母等材料的层之间。在脆性金属和合金中的脆性微量成分中，沿特定晶面发生解理。 |
| Precipitation heat treatment | 沉淀热处理 |
Artificial aging in which a constituent precipitates from a supersaturated solid solution. 成分从过饱和固溶体沉淀的人工时效。 |
| Water hammer | 水锤 |
The reflected pressure surge that occurs in a liquid flowing through a pipe, usually as a consequence of sudden closure of a valve. The surge may cause the pipe to vibrate and a hammering noise to be heard. Key factors affecting the surge amplitude are the compressibility of the liquid (especially if it contains undissolved gas) and the elasticity of the pipe wall. 在流经管道的液体中发生的反射压力波动，通常是阀门突然关闭的结果。浪涌可能导致管道振动，并听到锤击噪音。影响喘振幅度的关键因素是液体的可压缩性（特别是当其含有未溶解气体时）和管壁的弹性。 |
| Thermal reactor | 热反应器 |
An enlarged exhaust manifold bolted directly to the cylinder head of a piston engine, in which the oxidation of carbon monoxide and unburned hydrocarbons in the exhaust gas is enhanced. 一种扩大的排气歧管，直接用螺栓固定在活塞式发动机的气缸盖上，其中一氧化碳和未燃烧碳氢化合物的氧化作用增强。 |
| Gamma iron | 加马铁 |
The face-centered cubic form of pure iron, stable from 910 to 1400 °C (1670 to 2550 °F). 纯铁的面心立方形式，在910至1400°C（1670 2550°F）温度范围内稳定。 |
| Brine quenching | 盐水淬火 |
A quench in which brine (salt water-chlorides, carbonates, and cyanides) is the quenching medium. The salt addition improves the efficiency of water at the vapor phase or hot stage of the quenching process. 一种淬火，其中盐水（盐水-氯化物、碳酸盐和氰化物）是淬火介质。添加盐提高了水在淬火过程的气相或热阶段的效率。 |
| Shim | 垫片 |
A thin piece of material, such as metal of accurately-known thickness, placed between two surfaces to ensure they are the correct distance apart. A thin piece of material placed between two surfaces to obtain a proper fit, adjustment, or alignment. The piece can also be analyzed to measure furnace carbon potential (that is, because while in the furnace it will quickly carburize to a level equal to the furnace carbon potential). 一块薄的材料，如厚度精确已知的金属，放置在两个表面之间，以确保它们之间的距离正确。放置在两个表面之间以获得适当配合、调整或对齐的一块薄材料。还可以对工件进行分析，以测量熔炉碳势（也就是说，在熔炉中，工件将快速渗碳至与熔炉碳势能相等的水平）。 |
| Standard | 标准 |
(standard specification) A set of specifications for components, machines, materials, or processes intended to achieve uniformity, efficiency, and a specified quality. In the UK, standards issued by the British Standards Institution (BSI) are now generally those of the International Organization for Standardization (ISO). （标准规范）为实现一致性、效率和特定质量而制定的一套组件、机器、材料或工艺规范。在英国，英国标准协会（BSI）发布的标准现在基本上是国际标准化组织（ISO）的标准。 |
| Bond strength (Unit Pa) | 结合强度（单位Pa） |
The tensile, compressive or shear stress at which joints fail, e.g. by fracture or excessive deformation. 接头失效的拉伸、压缩或剪切应力，例如断裂或过度变形。 |
| Critical point | 临界点 |
(1) The temperature or pressure at which a change in crystal structure, phase or physical properties occurs. Same as transformation temperature. (2) In an equilibrium diagram, that specific value of composition, temperature and pressure, or combinations thereof, at which the phases of a heterogeneous system are in equilibrium. （1） 晶体结构、相或物理性质发生变化的温度或压力。与转变温度相同。（2） 在平衡图中，指组成、温度和压力或其组合的特定值，在该值下，多相体系的相处于平衡状态。 |
| Uniform strain | 均匀应变 |
The strain occurring prior to the beginning of localization of strain (necking); the strain to maximum load in the tension test. 在应变局部化（颈缩）开始之前发生的应变；拉伸试验中最大载荷的应变。 |
| Pitch (Unit m) | 间距（单位：m） |
1. In a cascade of identical turbine or compressor blades, the distance between successive blades measured parallel to the leading edges. 2. For a screw thread, the distance between adjacent thread forms measured parallel to the thread axis. 3. For an aircraft, the vertical relationship between the nose and the horizon. The pitch axis is an axis in the plane of the wings of an aircraft, perpendicular to the centreline, about which the aircraft rotates. Pitch motion is the corresponding up or down movement of the aircraft nose. Pitch attitude is the angle between the centreline of an aircraft and the horizontal. The angle is positive when the nose is above its position when the centreline is horizontal. 1.在相同涡轮或压缩机叶片的叶栅中，平行于前缘测量的连续叶片之间的距离。2.对于螺纹，平行于螺纹轴线测量的相邻螺纹形状之间的距离。3.对于飞机，机头和水平线之间的垂直关系。俯仰轴是飞机机翼平面内垂直于中心线的轴，飞机绕中心线旋转。俯仰运动是飞机机头的相应向上或向下运动。俯仰姿态是飞机中心线与水平线之间的角度。当中心线水平时，当机头高于其位置时，角度为正。 |
| Pressure ratio | 压力比 |
One pressure divided by another which may be a reference pressure. In many flow and thermodynamic processes, the pressure ratio is more important than the absolute pressure levels. For example, in compressible gas flow the Mach number is determined by the ratio of the stagnation pressure to the static pressure. 一个压力除以另一个压力，该压力可以是参考压力。在许多流动和热力学过程中，压力比比绝对压力水平更重要。例如，在可压缩气流中，马赫数由停滞压力与静压之比决定。 |
| Forging | 锻造处理 |
The process of forming raw steel into specified shapes. Some examples of forged products would be hex bolts, clevises, and barrier pins. 1. A method of component manufacture by hammering metal by hand or by machine (drop forge, press). 2. A part made by the process of forging. 将生钢制成特定形状的过程。锻造产品的一些例子是六角螺栓、U形夹和障碍销。 1. 一种通过手工或机器锤击金属（落锻、压力机）制造部件的方法。2.通过锻造工艺制成的零件。 |
| Centrifugal force (Unit N) | 离心力（单位N） |
The inertial reaction force to the centripetal force. It is equal in magnitude but opposite in direction. 惯性反作用力对向心力。它的大小相等，但方向相反。 |
| Flange | 法兰 |
Flange refers to a head style for bolts where there is a circular ‘flange’ under the head that acts like a washer to distribute a load. A flange is a projected flat rim or collar. 1. Annular rims at the ends of pipes (flanged pipe) or shafts by which they may be coupled together using bolts that pass through holes in the flanges (flange coupling, flange union), or by toggle clamps around the periphery. 2. An extended rim on a wheel that positions it laterally on a track. Commonly used for railway rolling stock. 3. The top and bottom parts of an I-beam. 法兰是指螺栓的头部样式，其中头部下方有一个圆形“法兰”，其作用类似于垫圈以分配载荷。凸缘是凸出的平轮辋或凸缘。1.管道（法兰管）或轴端部的环形边缘，通过这些边缘，可以使用穿过法兰孔的螺栓（法兰联轴器、法兰接头）或通过周边的肘节夹将管道连接在一起。2.车轮上的延伸轮辋，将其横向定位在轨道上。通常用于铁路车辆。3.工字梁的顶部和底部。 |
| Press quenching | 压淬 |
A quench in which hot dies are pressed and aligned with a part before the quenching process begins. Then the part is placed in contact with a quenching medium in a controlled manner. This process avoids part distortion. 一种淬火方法，在淬火过程开始之前，热模具被压制并与零件对齐。然后将零件以受控方式放置在与淬火介质接触的位置。该过程避免了零件变形。 |
| Relative humidity (ϕ) | 相对湿度（ψ） |
The ratio or percentage of the actual mass of moisture in a given volume of air at a given temperature to the maximum possible mass of moisture at the same temperature. 给定温度下给定体积空气中的实际水分质量与相同温度下的最大可能水分质量的比率或百分比。 |
| Annealing twin | 退火孪晶 |
A twin form in a crystal during recrystallization. 重结晶过程中晶体中的孪晶形式。 |
| Wind pump | 风泵 |
A pump driven directly by a windmill on a tower. Widely used in remote locations. 由塔上的风车直接驱动的泵。广泛应用于偏远地区。 |
| Rated load (Unit N) | 额定负荷（单位：N） |
The maximum load that a structure or component has been designed to carry. 结构或部件设计承受的最大荷载。 |
| Blank nitriding | 空白渗氮 |
Simulating the nitriding operation without introducing nitrogen. This is usually accomplished by using an inert material in place of the nitriding agent or by applying a suitable protective coating to the ferrous alloy. 在不引入氮气的情况下模拟氮化操作。这通常通过使用惰性材料代替氮化剂或通过在铁合金上施加合适的保护涂层来实现。 |
| Double tempering | 双回火 |
A treatment in which a quench-hardened ferrous metal is subjected to two complete tempering cycles, usually at substantially the same temperature, for the purpose of ensuring completion of the tempering reaction and promoting stability of the resulting microstructure. 一种处理，其中淬火硬化的黑色金属经过两个完整的回火循环，通常在基本相同的温度下，以确保完成回火反应并提高所得微观结构的稳定性。 |
| Spring | 弹簧 |
An elastic component which stores mechanical energy and exerts a force when deformed. The slope of the curve of applied force F to the deflexion of a spring x, dF/dx, is termed the spring rate or spring modulus k with unit N/m. For a linear spring, the F(x) curve is proportional and k is called the spring constant. An elastic device which yields under stress or pressure but returns to its original state or position when the stress or pressure is removed. 储存机械能并在变形时施加力的弹性部件。作用力F与弹簧x偏转的曲线斜率dF/dx称为弹簧率或弹簧模量k，单位为N/m。对于线性弹簧，F（x）曲线成比例，k称为弹簧常数。一种弹性装置，在应力或压力下屈服，但在应力和压力消除后恢复到其原始状态或位置。 |
| Dead space | 死区 |
(dead volume) (Unit m³) That volume of a gas-filled thermometer in which the gas is not at the same temperature as that being measured. （死容）（单位m³）充气温度计的体积，其中气体的温度与被测温度不同。 |
| Acceleration due to gravity | 重力加速度 |
(acceleration of free fall, gravitational acceleration, g) (Unit m/s²) The acceleration of a freely-falling body in a vacuum, with a mean value at sea level of approximately 9.81 m/s². （自由落体加速度，重力加速度，g）（单位m/s²）自由落体在真空中的加速度，在海平面处的平均值约为9.81m/s²。 |
| Compression member | 压缩构件 |
A structural component, the major loading on which is compressive. 一种结构部件，其上的主要载荷是压缩的。 |
| Young’s modulus | 杨氏模量 |
A term used synonymously with modulus of elasticity. The ratio of tensile or compressive stresses to the resulting strain. 与弹性模量同义的术语。拉伸或压缩应力与产生应变的比率。 |
| Compressive stress (Unit Pa) | 压缩应力（单位Pa） |
The compressive load per unit area at a point in a component. 部件中某点的每单位面积的压缩载荷。 |
| Compression pressure (Unit Pa) | 压缩压力（单位Pa） |
The pressure produced in a cylinder of a piston engine by compression of air in the absence of fuel. 在没有燃料的情况下通过压缩空气在活塞发动机的气缸中产生的压力。 |
| Stead’s brittleness | 斯特德脆性 |
A condition of brittleness that causes transcrystalline fracture in the coarse grain structure that results from prolonged annealing of thin sheets of low-carbon steel previously rolled at a temperature below about 705 °C (1300 °F). The fracture usually occurs at about 45° to the direction of rolling. 一种脆性状态，导致粗晶结构中发生穿晶断裂，这是由于之前在低于约705°C（1300°F）的温度下轧制的低碳钢薄板经过长时间退火造成的。断裂通常发生在与轧制方向约45°处。 |
| Crystalline defects | 结晶缺陷 |
The deviations from a perfect three-dimensional atomic packing that are responsible for much of the structure-sensitive properties of the materials. Crystal defects can be point defects (dislocations) or surface defects (vacancies), line defects (dislocations), or surface defects (grain boundaries). 与完美的三维原子堆积的偏差是造成材料的大部分结构敏感特性的原因。晶体缺陷可以是点缺陷（位错）或表面缺陷（空位）、线缺陷（位错）或表面缺陷（晶界）。 |
| Austempering | 等温淬火 |
A heat treatment for ferrous alloys in which a part is quenched from the austenitizing temperature at a rate fast enough to avoid formation of ferrite or pearlite and then held at a temperature just above Ms until transformation to bainite is complete. Although designated as bainite in both austempered steel and austempered ductile iron (ADI), austempered steel consists of two phase mixtures containing ferrite and carbide, while austempered ductile iron consists of two phase mixtures containing ferrite and austenite. Heat treatment comprising austenitization of a steel article, cooling it to a bainitic range at a rate higher than the critical cooling rate and holding at a fixed temperature until the completion of bainitic transformation. 一种铁合金的热处理，其中零件从奥氏体化温度以足够快的速度淬火，以避免形成铁素体或珠光体，然后保持在略高于Ms的温度，直到完全转变为贝氏体。虽然在奥氏体钢和奥氏体球铁(ADI)中都被指定为贝氏体，但奥氏体钢由含有铁素体和碳化物的两相混合物组成，而奥氏体球墨铸铁由含有铁素体和奥氏体的两相混合物组成。热处理包括钢制品的奥氏体化，以高于临界冷却速率的速率将其冷却到贝氏体范围，并保持在固定温度直到贝氏体转变完成。 |
| Cavitation damage | 气蚀损坏 |
Erosion of a solid surface through the formation and collapse of cavities or bubbles in an adjacent liquid that contains vapor and/or gas. 通过在包含蒸汽和/或气体的相邻液体中形成空穴或气泡并破坏固体表面。 |
| Ausforming | 形变热处理 |
Thermomechanical treatment of steel in the metastable austenitic condition below the recrystallization temperature followed by quenching to obtain martensite and/or bainite. 在低于再结晶温度的亚稳态奥氏体条件下对钢进行热机械处理，然后淬火以获得马氏体和/或贝氏体。 |
| Snap temper | 快速回火 |
A precautionary interim stress-relieving treatment applied to high-hardenability steels immediately after quenching to prevent cracking because of delay in tempering them at the prescribed higher temperature. 在淬火后立即对高淬透性钢进行预防性临时应力消除处理，以防止因在规定的更高温度下回火延迟而开裂。 |
| Allotropy | 同素异形体 |
A near synonym for polymorphism. Allotropy is generally restricted to describing polymorphic behavior in elements, terminal phases, and alloys whose behavior closely parallels that of the predominant constituent element. 多态性的近义词。同素异形体通常仅限于描述元素、终端相和合金中的多晶型行为，其行为与主要组成元素的行为非常相似。 |
| Screw machine | 螺丝机 |
A machine tool for high-volume manufacture of small turned components from rod or bar. 一种用棒或棒大批量制造小零件的机床。 |
| Torque coefficient | 扭矩系数 |
1. (KT) For a propeller of diameter D, a non-dimensional parameter defined by KT = T/ρΩ2D5 where Ω is the rotational speed (in rad/s) and ρ is the fluid density. 2. (CT) An alternative to (1) for a wind turbine, defined by CT = 2T/ρV2AR where V is the wind speed, A is the swept area of the blades, and R is the blade radius. 3. (K) An empirical coefficient used to calculate the torque T required to achieve an axial load F in a bolt according to T = KFd where d is the nominal bolt diameter. 1.（KT）对于直径为D的螺旋桨，由KT=T/ρΩ2D5定义的无量纲参数，其中Ω是转速（单位为rad/s），ρ是流体密度。2.（CT）对于风力涡轮机（1）的替代方案，由CT=2T/ρV2AR定义，其中V是风速，a是叶片的扫掠面积，R是叶片半径。3.（K）经验系数，用于根据T=KFd计算螺栓中实现轴向载荷F所需的扭矩T，其中d是螺栓标称直径。 |
| Coated abrasive | 涂附磨具 |
An abrasive tool consisting of a flexible backing material, such as a woven cloth, paper or vulcanized fibre, a bond material, such as a glue or synthetic resin, and grit. 一种研磨工具，由柔性背衬材料（例如编织布、纸或硫化纤维）、粘合材料（例如胶水或合成树脂）和砂砾组成。 |
| Dowel | 销钉 |
A headless cylindrical pin that fits into corresponding holes in mating components, thus ensuring relative location. A round metal or wooden pin. A pin, usually of circular shape like a cylinder, used to pin or fasten something in position temporarily or permanently. 一种圆头金属或木制圆柱销，可插入配合组件的相应孔中，从而确保相对位置，用于暂时或永久地将某物固定或固定到位。 |
| Preload relaxation | 预载松弛 |
Local yielding, due to excess bearing stress under nuts and bolt heads (caused by high local spots, rough surface finish, and lack of perfect squareness of bolt and nut bearing surfaces), may result in preload relaxation after preloads are first applied to a bolt. 由于螺母和螺栓头下的轴承应力过大（由局部斑点高、表面粗糙以及螺栓和螺母轴承表面缺乏完美的方正度造成），局部屈服可能会在首次向螺栓施加预载荷后导致预载荷松弛。 |
| Sliding-vane compressor | 滑片压缩机 |
(rotary-vane compressor, vane compressor) A rotary compressor in which gas is compressed as the spaces between spring-loaded sliding vanes held in an offset rotor reduce as the rotor revolves within a cylindrical housing. （旋转叶片压缩机，叶片压缩机）一种旋转式压缩机，当转子在圆柱形外壳内旋转时，偏置转子中的弹簧加载滑动叶片之间的空间减小，从而压缩气体。 |
| Radial wave equation | 径向波动方程 |
A differential equation describing the transmission of a wave in a system with radial symmetry. 描述波在径向对称系统中传输的微分方程。 |
| Chain | 链 |
A series of connected links, typically of steel. For lifting, pulling, securing, etc., each link is a closed loop, often in the form of a ring. For power transmission, the links are designed to mesh with the teeth of a sprocket wheel. In contrast to belt drives, chain drives tend to be employed in high-torque applications. 一系列连接的链接，通常是钢制的。对于提升、拉动、固定等，每个链节都是一个闭合环，通常呈环形。对于动力传输，链节设计为与链轮的齿啮合。与皮带传动相比，链传动往往用于高扭矩应用。 |
| Wrap-around bend | 环绕弯曲 |
The bend obtained when a specimen is wrapped in a closed helix around a cylindrical mandrel. This term is sometimes applied to a semiguided bend of 180° or less. 当试样缠绕在圆柱形心轴周围的闭合螺旋中时获得的弯曲。该术语有时适用于180°或更小的半导弯曲。 |
| Oldham coupling | 十字联轴节 |
(double-slider coupling) A device for connecting a pair of misaligned parallel shafts, on the end of each of which are flanges having diametral tenons (tongues) that engage with matching slots spaced at 90° in an intermediate disc. As the coupling rotates, the disc compensates for shaft offset by sliding along each tenon in turn. Low-friction surfaces are requisite and the disc is often made of a polymer. An alternative arrangement has the slots in the flanges and the tenons on the disc. （双滑块联轴器）一种连接一对未对准平行轴的装置，在每个平行轴的端部有法兰，法兰具有直径榫（舌），与中间盘中间隔90°的匹配槽接合。当联轴器旋转时，圆盘通过依次沿每个榫头滑动来补偿轴偏移。低摩擦表面是必需的，阀盘通常由聚合物制成。另一种布置方式是法兰上的槽和阀盘上的榫头。 |
| Fatigue | 疲劳 |
The phenomenon leading to fracture under repeated or fluctuating stresses having a maximum value less than the ultimate tensile strength of the material. Fatigue failure generally occurs at loads that, applied statically, would produce little perceptible effect. Fatigue fractures are progressive, beginning as minute cracks that grow under the action of the fluctuating stress. A term referring, in components and structures subjected to either random or cyclic periodically-varying loads, to a progressive reduction in strength leading to failure at stresses lower than those that cause failure under monotonic loading. Variable loads arise from outof-balance machinery and other vibration sources, wind gusts, etc., and a large proportion of service failures is caused by fatigue. Fatigue results from the initiation and slow propagation of cracks. In manufactured components, crack initiation usually occurs at a point of stress concentration. After a period, often of millions of stress cycles, the crack reaches a critical length at which the next peak load causes sudden brittle or ductile fracture. Fracture surfaces resulting from fatigue display characteristic striations or progression marks emanating from the crack initiation site during the slow crack growth period, with a different surface appearance for the final fracture. 在最大值小于材料极限抗拉强度的重复或波动应力下导致断裂的现象。疲劳失效通常发生在静态施加的载荷下，不会产生明显影响。疲劳断裂是渐进性的，从在波动应力作用下生长的微小裂纹开始。在承受随机或周期性变化载荷的部件和结构中，指强度逐渐降低，导致在低于单调载荷下导致失效的应力下发生失效的术语。可变负载由失衡的机械和其他振动源、阵风等引起，大部分故障是由疲劳引起的。疲劳是裂纹萌生和缓慢扩展的结果。在制造部件中，裂纹萌生通常发生在应力集中点。在一段时间（通常是数百万次应力循环）后，裂纹达到临界长度，此时下一个峰值载荷会导致突然脆性或韧性断裂。疲劳产生的断裂表面在缓慢裂纹扩展期间显示出从裂纹萌生部位发出的特征条纹或进展标记，最终断裂的表面外观不同。 |
| Concentration ratio | 浓度比 |
For a concentrating solar collector, the ratio of the projected area of the concentrator facing the solar beam to the actual area of the receiver. 对于聚光太阳能集热器，集中器面向太阳光束的投影面积与接收器的实际面积之比。 |
| Binary vapour cycle | 二元蒸气循环 |
A power cycle which combines a steam cycle at relatively low temperature (the bottoming cycle) with a higher temperature cycle (the topping cycle) in which a working fluid such as mercury, sodium or potassium is used. 一种动力循环，它将相对低温的蒸汽循环（底部循环）与高温循环（顶部循环）相结合，其中使用了诸如汞、钠或钾之类的工作流体。 |
| Dynamic recovery | 动态恢复 |
A process occurring in hot working of metals in which a fine subgrain structure forms within the elongated grains due to annihilation of dislocations due to easy cross slip and climb. It results in a lowering of the flow stress. Dynamic recovery, as opposed to dynamic recrystallization that occurs in hot working, occurs in metals of high stacking fault energy such as aluminum, αiron, and most bcc metals. 金属热加工中发生的一种过程，由于易于交叉滑动和攀爬，位错湮灭，细长晶粒内形成细亚晶粒结构。这导致流动应力降低。与热加工中发生的动态再结晶相反，动态回复发生在高层错能金属中，如铝、α铁和大多数bcc金属。 |
| Cavitation | 空蚀空化 |
The formation of vapour- or gas-filled cavities in a liquid due to reduction of the local pressure, often due to acceleration of the fluid, such as in flow through a convergent nozzle. If there is no dissolved gas in the liquid, vaporous cavitation occurs when the pressure falls below the saturated vapour pressure. If the bubbles are formed due to high temperature, the process is termed boiling. If there is dissolved gas, gaseous cavitation occurs due to pressure reduction, temperature increase, or diffusion (degassing). At the tips of marine propellers and in hydraulic machinery, the collapse of cavitation bubbles can cause noise and vibration and lead to surface damage in the form of pitting. 由于局部压力降低而在液体中形成充满蒸汽或气体的空腔，通常原因是流体的加速，例如收敛喷嘴的流动。如果液体中没有溶解气体，当压力降至饱和蒸汽压力以下时，会发生蒸汽空化。如果气泡是由于高温形成的，则该过程称为沸腾。如果存在溶解气体，则由于压力降低、温度升高或扩散（脱气），会发生气穴。在船用螺旋桨尖端和液压机械中，空化气泡的破裂可能会引起噪音和振动，并导致以点蚀形式出现的表面损坏。 |
| Alloy steels | 合金钢 |
Steels that contain alloying elements such as chromium, nickel, molybdenum, manganese, silicon, tungsten, and vanadium. These are added to improve properties such as the hardenability, toughness, strength, wear resistance, and corrosion resistance compared with those of plain-carbon steel. Low-alloy steels have a total alloy content (including carbon) of less than about 8%. They are hardenable and have strength up to 30% higher than plain-carbon steels. High-alloy steels contain considerably more alloy content and are developed for specific properties such as superior corrosion and chemical resistance. 含有铬、镍、钼、锰、硅、钨和钒等合金元素的钢。添加这些是为了提高与普通碳钢相比的淬透性、韧性、强度、耐磨性和耐腐蚀性等性能。低合金钢的总合金含量（包括碳）小于约8%。它们是可硬化的，强度比普通碳钢高出30%。高合金钢含有相当多的合金含量，并针对特定性能而开发，例如卓越的耐腐蚀性和耐化学性。 |
| Net weight (Unit N) | 净重（单位：N） |
The difference between the gross weight of any container including its contents and the tare weight of the empty container. 任何容器（包括其内容物）的毛重与空容器皮重之间的差值。 |
| Valve spring | 气门弹簧 |
The spring that restores a valve to its closed position after having been opened, and is also intended to prevent valve bounce. 在阀门打开后将其恢复到关闭位置的弹簧，也用于防止阀门反弹。 |
| Sample average | 样本平均值 |
The sum of all the observed values in a sample divided by the sample size. It is a point estimate of the population mean. Also known as arithmetic mean. 样本中所有观察值的总和除以样本大小。它是总体平均值的点估计。也称为算术平均值。 |
| Water column | 水柱 |
Water in a tube, which may be vertical or inclined. If the tube is open to the atmosphere, the vertical height h from a datum level to the water surface is a measure of the water static pressure p at the datum level given by p − B = ρgh where B is the barometric pressure, ρ denotes the water density, and g is the acceleration due to gravity. 管道中的水，可以是垂直的或倾斜的。如果管道向大气开放，则从基准面到水面的垂直高度h是基准面处水静压p的量度，由p给出−B=ρgh，其中B是大气压力，ρ表示水密度，g是重力引起的加速度。 |
| Rupture stress | 断裂应力 |
The stress at failure. Also known as breaking stress. 失效时的应力。也称为破裂应力。 |
| Relaxation | 松弛 |
The loss of tension, and therefore Clamping force, in a bolt and joint as a result of Embedment, vibration loosening, gasket creep, differential thermal expansion, etc. 由于嵌入、振动松动、垫圈蠕变、热膨胀差等原因，螺栓和接头中的张力损失，因此夹紧力损失。 |
| Rosette | 玫瑰形的结 |
Strain gages arranged to indicate, at a single position, strain in three different directions. 应变计布置成在单个位置指示三个不同方向的应变。 |
| Honing | 珩磨 |
Honing is a controlled, low-speed sizing and surface-finishing process in which stock is removed by the shearing action to the bonded abrasive grains of a honing stone, or stick. Finish polishing of surfaces and cutting edges in which very fine abrasive powders, such as rouge, are employed. Honing is usually applied to cylindrical surfaces and lapping to flat, but the usage is not consistent. 珩磨是一种受控的低速尺寸和表面精加工工艺，其中通过对珩磨石或棒的粘结磨粒的剪切作用去除原料。表面和切削刃的精抛光，其中使用了非常细的研磨粉，例如胭脂。珩磨通常用于圆柱面，研磨至平面，但用法并不一致。 |
| Surface tension (σ, γ) (Unit N/m) | 表面张力（σ，γ）（单位：N/m） |
At the interface between a liquid and a gas or two immiscible liquids, unbalanced cohesive forces acting on the liquid molecules at the interface lead to the property surface tension which causes tensile forces to develop as if it were a skin or membrane. 液体和气体或两种不混溶液体之间的界面处，作用在界面处的液体分子上的不平衡内聚力导致表面张力的性质，从而导致张力的发展，就像皮肤或薄膜一样。 |
| Gasket factors | 垫片系数 |
Experimentally derived ‘‘constants’’ used to define the behavior of a gasket or the assembly and in-service conditions required for acceptable behavior. 实验得出的“常数”用于定义垫圈的行为或可接受行为所需的组件和使用条件。 |
| Displacement | 移位 |
The distance that a chosen measurement point on a cracked specimen displaces normal to the crack plane as the crack grows. 随着裂纹扩展，裂纹试样上选定的测量点垂直于裂纹平面位移的距离。 |
| Swept volume (Unit m³) | 扫描体（单位m³) |
In the cylinder of a piston engine or other device, the volume between top and bottom dead centre positions of a piston; equal to πR2S where R is the piston radius and S is the stroke. 在活塞发动机或其他装置的气缸中，活塞上止点和下止点位置之间的体积；等于πR2S，其中R是活塞半径，S是冲程。 |
| Fracture mechanics | 断裂力学 |
The stress analysis of bodies containing cracks. The use of stressconcentration factors and other correction factors of traditional strength of materials is inadequate when flaws are present initially (or develop during loading), since fracture depends not only on stress but also the size of the crack. Traditional strength of materials stress calculations cannot predict either the safe working stress in the presence of a known flaw, or the critical size of flaw just tolerable with a given working stress. 含裂纹物体的应力分析。当初始存在缺陷（或在加载过程中形成缺陷）时，使用应力集中系数和传统材料强度的其他修正系数是不够的，因为断裂不仅取决于应力，还取决于裂纹的大小。传统的材料强度应力计算既不能预测已知缺陷存在时的安全工作应力，也不能预测给定工作应力下可容忍的缺陷临界尺寸。 |
| Homogeneous carburizing | 均匀渗碳 |
Use of a carburizing process to convert a low-carbon ferrous alloy to one of uniform and higher carbon content throughout the section. 使用渗碳工艺将低碳铁合金转化为整个截面中碳含量均匀且较高的合金。 |
| Ball screw and nut | 滚珠丝杠和螺母 |
A nut and bolt assembly having semi-circular helical grooves, as opposed to threads, in which run ball bearings. On rotation of the nut, the balls move along the helix and carry the axial load. Balls reaching the end of the groove are recirculated back to the beginning. Such devices have low friction and very little backlash, and are used in some steering mechanisms. 一种螺母和螺栓组件，具有半圆形螺旋槽，与螺纹相反，在其中运行滚珠轴承。在螺母旋转时，滚珠沿螺旋线移动并承受轴向载荷。到达凹槽末端的滚珠被循环回起点。这种装置具有低摩擦和非常小的背隙，并且用于一些转向机构。 |
| Blow moulding | 吹塑 |
The manufacture of hollow polymer objects (e.g. bottles) by expanding, with internal air pressure, a tube sealed at one end (parison) against the walls of a cavity mould. 通过使用内部气压使一端密封的管子（型坯）靠在型腔模具的壁上膨胀来制造中空聚合物物体（例如瓶子）。 |
| Semi-rotary pump | 半回转泵 |
A form of self-priming pump, often hand-operated, suitable for pumping water and light oils such as diesel oil and petrol. As shown in the diagram, liquid is sucked into one side of the pump through flap valves and simultaneously ejected from the other side on one stroke. The sequence is reversed on each successive stroke. 一种自吸泵，通常是手动的，适用于泵送水和轻油，如柴油和汽油。液体通过翻板阀吸入泵的一侧，同时在一个冲程中从另一侧排出。在每个连续冲程上，顺序颠倒。 |
| Breaking load (Unit N) | 断裂负荷（单位N） |
The load applied at some point to a component or structure which leads to fracture. The breaking stress (breaking strength) is the average stress at which a member breaks, given by the breaking load divided by the area over which it acts. 在某个点施加到导致断裂的部件或结构的载荷。断裂应力（断裂强度）是构件断裂时的平均应力，由断裂载荷除以其作用的面积给出。 |
| Socket head | 凹头 |
Screw head having a hexagonal or other form of recessed socket in the head so that the screw can be turned with a wrench or key, as a hexagon key. 螺钉头上有六角或其他形式的凹座，可以用扳手或钥匙（如六角钥匙）转动螺钉。 |
| Effective radius of nut, bolt head, or threads | 螺母、螺栓头或螺纹的有效半径 |
Distance between the geometric center of the part and the circle of points through which the resultant contact forces between mating parts passes. Must be determined by integration. 零件几何中心与配合零件之间的合力通过的点圆之间的距离。必须通过积分来确定。 |
| Shore hardness | 肖氏硬度 |
A measure of the hardness of materials such as elastomers, plastics, and rubbers determined using a Shore durometer which measures the penetration depth of a hardened steel rod (the indenter) 1.1–1.4 mm in diameter into the test material for a given force applied rapidly with a calibrated spring. There are two main indenter designs: type A (for softer materials) for which the end of the rod is a truncated 35° cone tapering to a diameter of 0.79 mm, and type D (harder materials) for which the end is a 30° cone with a 0.1 mm radius tip. The spring force is 8.05 N for type A and 44.45 N for type D. The hardness value is related to the penetration depth (limited to a maximum of 2.5 mm) such that for zero penetration the hardness is 100 and for maximum penetration the hardness is zero. The relevant standards are ISO 48-1, 48-4, and 48-7. Shore hardness values of selected materials are as follows: ABS 100, cellulose acetate 50–95, high-density polyethylene 60–70, low density polyethylene 40–50, polymethylmethacrylate 90–99, PTFE 50–65, and plasticized PVC 15–70. 使用肖氏硬度计测量弹性体、塑料和橡胶等材料的硬度，肖氏硬度仪测量直径为1.1–1.4mm的硬化钢棒（压头）在用校准弹簧快速施加的给定力下渗入试验材料的深度。有两种主要的压头设计：A型（适用于较软的材料），其杆端为截头35°锥形，逐渐变细至直径0.79 mm；D型（较硬的材料），端部为30°锥形，尖端半径为0.1mm。A型的弹簧力为8.05N，D型为44.45N。硬度值与渗透深度相关（最大限制为2.5mm），因此，对于零渗透，硬度为100，对于最大渗透，硬度是零。相关标准为ISO 48-1、48-4和48-7。所选材料的肖氏硬度值如下：ABS100、醋酸纤维素50-95、高密度聚乙烯60-70、低密度聚乙烯40-50、聚甲基丙烯酸甲酯90-99、PTFE50-65和塑化PVC15-70。 |
| Hydrodynamics | 流体力学 |
A term sometimes used to mean fluid dynamics, even when the fluid is a gas or a liquid other than water. 有时用于表示流体动力学的术语，即使流体是气体或水以外的液体。 |
| Hot isostatic pressing | 热等静压 |
Sintering of powdered materials at high temperature and high hydrostatic pressure in order to minimize porosity. 在高温和高静水压力下烧结粉末材料，以尽量减少孔隙率。 |
| Crest of screw thread | 螺纹牙顶 |
The top surface joining the two sides of flanks of a thread. 连接螺纹牙侧两侧的顶面。 |
| Ball mill | 球磨机 |
A mill for grinding and pulverizing materials, consisting of a horizontal rotating drum containing loose steel or ceramic balls. 一种用于研磨和粉碎物料的磨机，由装有松散钢球或陶瓷球的水平旋转滚筒组成。 |
| Ion carburizing | 离子渗碳 |
A method of surface hardening in which carbon ions are diffused into a workpiece in a vacuum through the use of high-voltage electrical energy. Synonymous with plasma carburizing or glowdischarge carburizing. 一种表面硬化方法，利用高压电能将碳离子在真空中扩散到工件中。与等离子渗碳或辉光放电渗碳同义。 |
| Crank pin | 曲柄销 |
It is a short shaft parallel to the axis of the crankshaft but radially offset from it, to which is attached the big end of a connecting rod in a bearing. Sometimes the crank pin is supported at one end only (a wrist pin) but in built-up or one-piece forged crankshafts, the crank pin is supported by thick plates (crank arms, crank webs) at either end. 它是一个短轴，平行于曲轴的轴线，但径向偏移，轴承中连杆的大端连接到该短轴上。有时曲柄销仅在一端支撑（腕销），在组合式或整体锻造曲轴中，曲柄销在两端由厚板（曲柄臂、曲柄腹板）支撑。 |
| Pressure gauge | 压力表 |
An instrument used to measure absolute or gauge pressure. The sensing element may be a tube which deflects when pressurized, as in a Bourdon gauge, a bellows as in an aneroid barometer, a piezoelectric crystal, a piezoresistive element, etc. 测量绝对压力或表压的仪器。传感元件可以是加压时会偏转的管，如波登压力表、无液气压计中的波纹管、压电晶体、压阻元件等。 |
| Fastener specification | 紧固件规格 |
A precise statement of set requirements to be satisfied by a fastener, its material, or its processing. It also indicates the procedure used to determine whether the requirements given are satisfied. 对紧固件、其材料或加工过程要满足的设定要求的精确陈述。它还指出了用于确定是否满足给定要求的程序。 |
| Fatigue limit | 疲劳极限 |
The maximum stress that presumably leads to fatigue fracture in a specified number of stress cycles. The value of the maximum stress and the stress ratio also should be stated. Compare with endurance limit. 在指定数量的应力循环中可能导致疲劳断裂的最大应力。还应说明最大应力值和应力比。与耐力极限比较。 |
| Centrifugal clutch | 离心离合器 |
A clutch that engages and disengages at a defined speed of rotation of the driving shaft, as when expanding friction shoes act against the inside of a drum. 一种离合器，以驱动轴规定的旋转速度接合和分离，如当膨胀的摩擦片作用在滚筒内部时。 |
| Arbitration bar | 抗弯试棒 |
A test bar, cast with a heat of material, used to determine chemical composition, hardness, tensile strength, and deflection and strength under transverse loading in order to establish the state of acceptability of the casting. 用热材料铸造的测试棒，用于确定化学成分、硬度、抗拉强度、横向载荷下的挠度和强度，以确定铸件的可接受状态。 |
| Screw extractor | 螺钉拔 |
A device for removing broken-off screws from threaded holes. It resembles a drill with, for broken right-hand threads, a fast (long-pitch) left-hand thread that is driven into a hole drilled in the broken screw, thus untwisting it. 从螺纹孔中去除断裂螺钉的装置。它类似于一个钻头，对于断裂的右螺纹，一个快速（长螺距）的左螺纹被打入在断裂螺钉上钻的孔中，从而将其松开。 |
| Compression fitting | 压缩接头 |
A screwed joint for pipework made resistant to leakage by permanent deformation of a closely-fitting ring, called a ferrule or olive, on tightening. 一种用于管道的螺纹接头，通过紧密配合的环（称为套圈或橄榄形）在拧紧时的永久变形来防止泄漏。 |
| Pin expansion test | 插头膨胀试验 |
A test for determining the ability of a tube to be expanded or for revealing the presence of cracks or other longitudinal weaknesses in it, made by forcing a tapered pin into the open end of the tube, similar to flare test. 通过将锥形销压入管道开口端来确定管道膨胀能力或揭示其存在裂纹或其他纵向缺陷的试验，类似于扩口试验。 |
| B-basis | B-基础 |
Mechanical property value above which at least 90% of the population of values is expected to fall, with a confidence of 95%. 机械性能值超过该值时，至少90%的值预计会下降，置信度为95%。 |
| Screw feeder | 螺旋给料机 |
A mechanism for handling bulk materials in which a rotating helicoidal screw moves the material axially forward. Similar to a screw conveyor, but required to discharge material at a controlled rate very accurately. It operates with the screw completely full. 一种用于处理散装物料的机构，其中旋转的螺旋螺杆使物料轴向向前移动。类似于螺旋输送机，但需要以受控速率非常精确地排出物料。它在螺杆完全充满的情况下运行。 |
| Annealing | 退火 |
A generic term denoting a treatment, consisting of heating to and holding at a suitable temperature followed by cooling at a suitable rate, used primarily to soften metallic materials, but also to simultaneously produce desired changes in other properties or in microstructure. 一个通用术语，表示一种处理，包括加热并保持在合适的温度，然后以合适的速率冷却，主要用于软化金属材料，但也同时产生其他性能或微观结构的所需变化。 |
| Mechanical properties of solid materials | 固体材料的力学性能 |
The strength and stiffness properties of solid materials such as fracture toughness, the moduli of elasticity, percent elongation, 固体材料的强度和刚度特性，例如断裂韧性、弹性模量、伸长率、 |
| Shear | 扭剪 |
The type of force that causes or tends to cause two contiguous parts of the same body to slide relative to each other in a direction parallel to their plane of contact. 导致或倾向于导致同一物体的两个相邻部分在平行于其接触面的方向上相对滑动的力的类型。 |
| Slug wrench | 缓动扳手 |
A box wrench with an anvil on the end of the handle. Torque is produced by striking the anvil with a sledge hammer. 柄端有铁砧的套筒扳手。扭矩是通过用大锤敲击铁砧产生的。 |
| Cyaniding | 氰化 |
A case-hardening process in which a ferrous material is heated above the lower transformation range in a molten salt containing cyanide to cause simultaneous absorption of carbon and nitrogen at the surface and, by diffusion, create a concentration gradient. Quench hardening completes the process. 一种表面硬化工艺，将含铁材料在含氰化物的熔融盐中加热至低于较低转变范围，使其表面同时吸收碳和氮，并通过扩散形成浓度梯度。淬火硬化完成该过程。 |
| Hooke’s law | 胡克定律 |
Within the limit of proportionality, the extension of a material is proportional to the applied force. Approximately, it is the relationship between stress and strain in an elastic material when it is stretched. The law states that the stress (force per unit area) is proportional to the strain (a change in dimensions). The law, which holds only approximately and over a limited range, was discovered in 1676 by Robert Hooke. 在比例极限内，材料的延伸与所施加的力成比例。近似地说，它是弹性材料拉伸时应力和应变之间的关系。该定律指出，应力（单位面积的力）与应变（尺寸变化）成比例。该定律仅适用于有限的范围，由罗伯特·胡克于1676年发现。 |
| Check valve | 止回阀 |
(clack valve, non-return valve) A mechanical device that allows fluid flow in one direction only. The numerous designs include ball, diaphragm, disc, lift, split disc, and swing check valves. （瓣阀、止回阀）一种仅允许流体单向流动的机械装置。众多设计包括球阀、隔膜阀、盘阀、升降阀、分体盘阀和旋启式止回阀。 |
| Crack size (a) | 裂纹尺寸（a） |
A lineal measure of a principal planar dimension of a crack. This measure is commonly used in the calculation of quantities descriptive of the stress and displacement fields. In practice, the value of crack size is obtained from procedures for measurement of physical crack size, original crack size, or effective crack size, as appropriate to the situation under consideration. 裂纹主平面尺寸的线性度量。这种测量通常用于计算描述应力场和位移场的量。在实践中，裂纹尺寸的值是通过测量物理裂纹尺寸、原始裂纹尺寸或有效裂纹尺寸的程序获得的，视情况而定。 |
| Impact strength 1. (Unit Pa) | 冲击强度1.（单位Pa） |
The stress to cause failure (by yielding or fracture) under conditions of high strain rate. 2. (Unit J) A term sometimes used to describe the energy required to fracture a specimen in a Charpy or Izod impact test even though the unit is not that of strength. 在高应变率条件下导致失效（通过屈服或断裂）的应力。2.（单位J）有时用于描述在夏比或悬臂梁式冲击试验中使样品断裂所需的能量，即使单位不是强度单位。 |
| Bypass valve | 旁通阀 |
A valve that directs flow through a bypass. 引导流过旁路的阀门。 |
| Fracture mechanisms | 断裂机制 |
The microstructural mechanisms that cause fracture, such as void initiation, growth and coalescence, cleavage. 导致断裂的微观结构机制，如空隙的萌生、生长和聚结、解理。 |
| Pressure (p) (Unit Pa) | 压力（p）（单位Pa） |
In thermodynamics and fluid mechanics, the compressive force exerted by the fluid per unit area. The pressure exerted by a fluid on a surface acts normal to the surface. 在热力学和流体力学中，每单位面积流体施加的压缩力。流体施加在表面上的压力垂直于表面。 |
| Hot shortness | 热脆性 |
The reduction of ductility in steels at high temperatures caused by melting of sulfides that wet grain boundaries and spread along them. 高温下钢的延展性降低，这是由于硫化物的熔化润湿晶界并沿晶界扩散而引起的。 |
| Ideal critical diameter | 理想临界直径 |
(DI). Under an ideal quench condition, the bar diameter that has 50% martensite at the center of the bar when the surface is cooled at an infinitely rapid rate (that is, when H = ∞, where H is the quench severity factor). （DI）在理想淬火条件下，当表面以无限快的速度冷却时（即H=∞, 其中H是淬火严重度因子）。 |
| Air pump | 气泵 |
A machine for providing a flow of air or for increasing or decreasing the mass and pressure of air in a closed container. The term pump is more usual when the working fluid is a liquid, while compressor is more usual for gases. 一种用于提供空气流动或用于增加或减少密闭容器中空气质量和压力的机器。当工作流体是液体时，术语泵更常用，而气体更常用压缩机。 |
| Abradant | 研磨剂 |
The differently sized grits of hard materials such as emery employed for grinding, polishing, etc. The abrasive grade is determined by the grit size (grit number) originally related to the hole sizes in wire sieves. 用于研磨、抛光等的硬质材料（例如金刚砂）的不同尺寸粒度。磨料等级由最初与金属丝筛孔尺寸相关的粒度（粒度数）决定。 |
| Ultimate strength | 极限应力 |
The maximum tensile strength a bolt or material can support prior to rupture. Always found in the plastic region of the stress–strain or force–elongation curve, and so is not a design strength. Also called Tensile strength and ultimate tensile strength. The maximum stress (tensile, compressive, or shear) a material can sustain without fracture, determined by dividing maximum load by the original cross-sectional area of the specimen. Also known as nominal strength or maximum strength. 螺栓或材料在断裂前可支撑的最大抗拉强度。总是出现在应力-应变或力-伸长率曲线的塑性区域，因此不是设计强度。也称为抗拉强度和极限抗拉强度。材料在不断裂的情况下能够承受的最大应力（拉伸、压缩或剪切），通过将最大载荷除以试样的原始横截面积来确定。也称为标称强度或最大强度。 |
| Fin neck carriage bolt | 翼颈圆头方颈螺栓 |
A plain, circular, oval head bolt with two oppositely located fins to prevent rotation. 一种普通的圆形椭圆头螺栓，有两个相对的翼片以防止旋转。 |
| Time quenching | 时间淬火 |
A term used to describe a quench in which the cooling rate of the part being quenched must be changed abruptly at some time during the cooling cycle. 用于描述淬火的术语，其中被淬火零件的冷却速率必须在冷却循环的某个时间突然改变。 |
| Mass flow rate (ṁ) (Unit kg/s) | 质量流量（ṁ）（单位kg/s） |
The mass of a material, usually a fluid or powder, that flows across a surface or through a pipe or other duct per unit time. The corresponding mass flux (ṁ″), with unit kg/s.m², is the mass flow across a real surface or through a duct, divided by the surface or cross-sectional area A, i.e. ṁ″ = ṁ/A or ṁ″ = ρV where ρ is the material density and V is its velocity normal to the surface. 单位时间内流过表面或通过管道或其他管道的材料质量，通常是流体或粉末。相应的质量通量（ṁ″），单位为kg/s.m²，是通过真实表面或通过管道的质量流量除以表面或横截面积A，即ṁ″=ṁ/A或ṁ″=ρV，其中ρ是材料密度，V是其垂直于表面的速度。 |
| Planar anisotropy | 平面异向性 |
A variation in physical and/or mechanical properties with respect to direction within the plane of material in sheet form. 在片状材料平面内，物理和/或机械性能相对于方向的变化。 |
| Critical temperature ranges | 临界温度范围 |
Synonymous with transformation ranges, which is the preferred term. 与转换范围同义，这是首选术语。 |
| Stress cycles endured (N) | 承受的应力循环（N） |
The number of cycles of a specified character (that produce fluctuating stress and strain) that a specimen has endured at any time in its stress history. 试样在其应力历史中任何时间所经受的特定特征（产生波动应力和应变）的循环次数。 |
| Heat balance (heat budget) | 热平衡（热预算） |
An energy balance involving only heat transfer across the system boundary and the stored energy. 仅涉及跨系统边界的热传递和存储能量的能量平衡。 |
| Scale effect | 规模效应 |
The change in behaviour with size of a material, component, or structure. For example, cube-square scaling where one element changes with volume and another with area, as in the range of a projectile or ship, droplet formation, and fracture mechanics. 性能随材料、部件或结构尺寸的变化。例如，立方体平方比例，其中一个元素随体积变化，另一个元素因面积变化，如在射弹或飞船的射程、液滴形成和断裂力学中。 |
| Waste heat | 废热 |
1. Heat generated by internal-combustion engines, gas turbines, electrical generators, electrical equipment, and industrial processes that is not used directly but is expelled to the environment, often in hot flue or exhaust gases. 2. Heat generated from waste 1.内燃机、燃气轮机、发电机、电气设备和工业过程产生的热量，这些热量不是直接使用的，而是通过热烟气或废气排放到环境中。2.废物产生的热量 |
| Vapour–pressure curve | 蒸汽压力曲线 |
For a pure substance, the curve of saturation pressure plotted vs saturation temperature. 对于纯物质，绘制了饱和压力与饱和温度的曲线。 |
| Die threading | 模具螺纹 |
Die threading is a machining process for cutting external threads in cylindrical or tapered surfaces by the use of solid or self-opening dies. Die threading is a slower method of producing external threads than thread rolling, but it is faster than single-point threading in a lathe. 模具螺纹加工是一种通过使用实心或自开模具在圆柱形或锥形表面上切削外螺纹的加工工艺。模具螺纹加工是一种比滚丝加工更慢的外螺纹加工方法，但它比车床中的单点螺纹加工要快。 |
| Oxidation | 氧化 |
(1) A reaction in which there is an increase in valence resulting from a loss of electrons. (2) A corrosion reaction in which the corroded metal forms an oxide; usually applied to reaction with a gas containing elemental oxygen, such as air. （1）因电子损失而导致价态增加的反应。（2）腐蚀反应，其中被腐蚀的金属形成氧化物；通常用于与含有元素氧的气体如空气反应。 |
| Torque converter | 变矩器 |
A turbomachine used for torque amplification consisting of an impeller, a turbine, and a reaction member. Applications include motor-vehicle transmissions. 用于扭矩放大的涡轮机，由叶轮、涡轮机和反作用构件组成。应用包括机动车变速器。 |
| Total head (hT) (Unit m) | 总水头（hT）（单位：m） |
Total pressure pT expressed in terms of the vertical height of a column of liquid, typically water or mercury, i.e. hT = pT/ρg where g is the acceleration due to gravity and ρ is the liquid density. 总压力pT以液体柱（通常为水或汞）的垂直高度表示，即hT=pT/ρg，其中g为重力加速度，ρ为液体密度。 |
| Total-loss lubrication | 全损耗润滑 |
A system in which the lubricating oil for an internal-combustion engine is burned together with the fuel. 内燃机润滑油与燃料一起燃烧的系统。 |
| Dilatation (dilation) | 膨胀 |
A change of volume caused by external load, compression, temperature change, chemical action, etc. 由外部载荷、压缩、温度变化、化学作用等引起的体积变化。 |
| Balance weight | 平衡器 |
A corrective mass used in the static or dynamic balancing of a rotating object. 用于旋转物体的静态或动态平衡的校正质量。 |
| Union (union joint) | 活接头 |
A threaded pipe fitting that allows two pipes to be connected anddetached without the need for either to be rotated, and without damaging the pipe ends. 一种螺纹管件，允许连接和拆卸两个管道，而无需旋转任何一个管道，且不会损坏管道端部。 |
| Pulse | 脉冲 |
An increase or decrease in the magnitude of a physical quantity, such as pressure, voltage, or force, with a time scale short compared with other time scales in a process, after which there is a return to the original level. 物理量的大小的增加或减少，如压力、电压或力，与过程中的其他时间尺度相比，时间尺度较短，之后返回到原始水平。 |
| Shoulder screw | 轴肩螺钉 |
A screw having two or more diameters or shoulders and commonly used for supporting levers and other machine parts that have to operate freely. 一种具有两个或两个以上直径或轴肩的螺钉，通常用于支撑杠杆和其他必须自由操作的机器部件。 |
| Swift cup test | 斯威夫特杯测试 |
A simulative cupping test in which circular blanks of various diameters are clamped in a die ring and deep drawn into cups by a flat-bottomed cylindrical punch. 一种模拟拔杯试验，将不同直径的圆形坯料夹紧在模环中，并用平底圆柱冲头将其深拉入杯中。 |
| Diagonal pitch (Unit m) | 对角线间距（单位米） |
The distance, when components in an assembly are staggered, between the position of a component in one row or column and the position of the corresponding component in the next row or column. The term is applied to rivets, turbine or compressor blades in a cascade, vortex generators on the surface of a wing, etc. 当部件中的零部件交错时，一行或一列中零部件的位置与下一行或下一列中相应零部件的位置之间的距离。该术语适用于铆钉、叶栅中的涡轮或压缩机叶片、机翼表面的涡流发生器等。 |
| Track rod | 横拉杆 |
A bar connecting the ends of the steering arms in an automotive vehicle. 连接汽车转向臂端部的杆。 |
| Transition metals | 过渡金属 |
Metallic elements from groups (columns) 3 to 12 of the periodic table. They include important metals such as titanium, vanadium, chromium, manganese, iron, cobalt, zirconium, niobium, molybdenum, tantalum, tungsten, and the noble metals. They have either body-centred cubic, face-centred cubic, or hexagonal close-packed crystal structure at room temperature and have a wide range of mechanical and physical properties. 元素周期表第3组至第12组（列）中的金属元素。它们包括重要的金属，如钛、钒、铬、锰、铁、钴、锆、铌、钼、钽、钨和贵金属。它们在室温下具有体心立方、面心立方或六方密排晶体结构，并具有广泛的机械和物理性能。 |
| Atomic volume | 原子体积 |
Volume of unit cell per atom. 每个原子的晶胞体积。 |
| Coefficient of discharge (CD) | 流量系数（CD） |
For flow through a nozzle or orifice plate, the ratio of the actual mass flow rate to the theoretical mass flow rate calculated assuming the flow to be isentropic. The coefficient of velocity (velocity coefficient) is the corresponding ratio of the actual average velocity to the theoretical value. For incompressible flow, the theoretical flow rate and velocity can be calculated using Bernoulli’s equation. 对于通过喷嘴或孔板的流量，实际质量流量与假设流量为等熵计算的理论质量流量之比。速度系数（速度系数）是实际平均速度与理论值的对应比。对于不可压缩流，可以使用伯努利方程计算理论流量和速度。 |
| Coefficient of rolling friction | 滚动摩擦系数 |
The ratio of force parallel to a surface, on which an object rolls, to the normal force. Unlike sliding friction, rolling friction depends on the size of the contact patch and the radius of the rolling element, and the behaviour depends on whether the contact is elastic, viscoelastic, or plastic and on hysteresis losses. 平行于物体滚动表面的力与法向力之比。与滑动摩擦不同，滚动摩擦取决于接触片的大小和滚动元件的半径，其行为取决于接触是弹性的、粘弹性的还是塑性的以及滞后损失。 |
| Centrifugal pump | 离心泵 |
A pump into which liquid enters axially through the eye of the casing and is then accelerated through an impeller, thereby increasing both its kinetic energy and pressure before being delivered to a ring diffuser (the volute) that further increases the liquid pressure and from which it leaves. 一种泵，液体通过泵壳的眼轴向进入，然后通过叶轮加速，从而在输送到环形扩散器（蜗壳）之前增加其动能和压力，从而进一步增加液体压力并从中流出树叶。 |
| Bolt gage | 螺栓量规 |
An ultrasonic instrument used to measure the stress or strain in bolts. 用于测量螺栓应力或应变的超声波仪器。 |
| Captive nut | 松脱螺母 |
A nut attached loosely or rigidly to a sheet member that is too thin to thread and which engages with a cap screw. 松脱地或刚性地连接到薄板构件上的螺母，该螺母太薄而无法拧入，并与带帽螺钉接合。 |
| Vice | 老虎钳 |
A workshop tool used to hold a workpiece and consisting of two jaws, one fixed and the other moved by turning a screw. 一种用于夹持工件的车间工具，由两个钳口组成，一个固定，另一个通过转动螺钉移动。 |
| Wind energy (Unit kJ) | 风能（单位kJ） |
The kinetic energy associated with wind that can be converted by a wind energy conversion system (WECS) into electrical or mechanical power by a rotor, such as a multi-bladed propeller, exposed to the wind. If the air density is ρ and the wind speed is V, then the kinetic energy flux is ρV3/2. The actual wind power that can be extracted by a wind turbine intercepting a cross section of wind A is CPρAV3/2 where CP is an empirical efficiency factor termed the power coefficient. The wind-energy distribution is a histogram of the calculated wind power that can be generated annually from the windspeed frequency distribution at a given location. A windmill generates mechanical power whereas a wind turbine (wind generator) generates electrical power. The largest wind turbine, manufactured by MHI Vestas, has a power rating of 9.5 MW, a rotor diameter of 164 m, and a hub height of 105 m (the highest wind turbines have heights in the region of 190 m). A wind farm is an array of wind turbines, typically ten to several hundred, at a single location, either onshore or offshore. Energy derived from wind is a major contributor to sustainable energy generation. The largest operational offshore wind farm, located in the Irish Sea, has 87 turbines and a total generating capacity of 659 MW. The largest onshore wind farm is in Kern County, California with some 586 turbines and a total capacity of 1 550 MW. 风能转换系统（WECS）可通过暴露于风中的转子（如多叶片螺旋桨）将与风相关的动能转换为电能或机械能。如果空气密度为ρ，风速为V，则动能通量为ρV3/2。可由截获风a横截面的风力涡轮机提取的实际风功率为CPρAV3/2，其中CP是称为功率系数的经验效率因子。风能分布是根据给定位置处的风速频率分布每年可产生的计算风力的直方图。风车产生机械功率，而风力涡轮机（风力发电机）产生电功率。MHI Vestas制造的最大风力涡轮机的额定功率为9.5MW，转子直径为164m，轮毂高度为105m（最高风力涡轮机的高度为190m）。风电场是一系列风力涡轮机，通常为十到几百台，位于单一位置，无论是陆上还是海上。风能是可持续能源发电的主要贡献者。最大的海上风电场位于爱尔兰海，拥有87台涡轮机，总发电容量为659MW。最大的陆上风电场位于加利福尼亚州克恩县，拥有约586台涡轮机，总容量为1550兆瓦。 |
| Accelerated testing | 加速测试 |
A type of testing, for rates of wear, fatigue, corrosion etc., in which failure times are reduced by employing greater loads, more frequent power cycling, higher vibration levels, higher humidity, higher temperatures, greater potential differences etc. than would be encountered in normal operation. 一种测试类型，用于测试磨损率、疲劳率、腐蚀率等，通过采用比正常运行中更大的负载、更频繁的功率循环、更高的振动水平、更高湿度、更高温度、更大的电位差等，减少故障时间。 |
| Quench (quenching) | 淬火 |
Rapid cooling. When applicable, the following more specific terms should be used: brine quenching, caustic quenching, cold die quenching, forced-air quenching, intense quenching, oil quenching, press quenching, spray quenching, direct quenching, fog quenching, hot quenching, interrupted quenching, selective quenching, time quenching, and water quenching. 1. The process of rapid-cooling by plunging an object into a bath of water, oil, salt, molten metal, or other media. It is a method of heat treatment used particularly to form martensite preparatory to tempering steels. The bath temperature is the quench temperature. 2. The suppression of combustion. 3. In a piston engine, the cooling of a fraction of the gases during combustion, typically by reducing the clearance between the piston crown and the cylinder head. 快速冷却。适用时，应使用以下更具体的术语：盐水淬火、碱淬火、冷模淬火、强制空气淬火、强淬火、油淬火、压力淬火、喷射淬火、直接淬火、雾淬火、热淬火、间断淬火、选择性淬火、时间淬火和水淬火。1.通过将物体放入水、油、盐、熔融金属或其他介质的浴中快速冷却的过程。这是一种热处理方法，特别用于形成回火钢前的马氏体。浴温度是淬火温度。2.燃烧的抑制。3.在活塞式发动机中，燃烧过程中一部分气体的冷却，通常通过减小活塞顶和气缸盖之间的间隙来实现。 |
| Centigrade heat unit | 摄氏热量单位 |
(Celsius heat unit, CHU) An obsolete (i.e. non-SI) unit equal to the energy required to increase the temperature of one pound of pure, air-free water from 14.5°C to 15.5°C at a pressure of one standard atmosphere. （摄氏热量单位，CHU）一个已被淘汰的（即非国际单位制）单位，等于在一个标准大气压的压力下将一磅纯净的无空气水的温度从14.5°C提高到15.5°C所需的能量. |
| Pressure difference (Unit Pa) | 压差（单位Pa） |
(pressure differential, Δp) The difference between two pressures, one of which may be a reference pressure such as barometric pressure. In many flow processes, the pressure difference is more important than the absolute pressure level. （压差，Δp）两个压力之间的差值，其中一个压力可以是参考压力，如大气压力。在许多流动过程中，压差比绝对压力水平更重要。 |
| International System of Units | 国际单位制 |
(SI system of units, Le Système international d’unités) The standard system of units now used almost universally in science and engineering except in the United States. The definitive reference on the SI is a booklet published by the International Bureau of Weights and Measures, often referred to as the BIPM SI Brochure. There are seven base units: metre (symbol m) for length; kilogram (kg) for mass; mole (mol) for amount of substance; second (s) for time; kelvin (K) for temperature; ampere (A) for electric current; and candela (cd) for luminous intensity. New SI unit definitions, based upon the values of the universal constants of nature (also termed the fundamental physical constants: the Avogadro constant, the Boltzmann constant, and the Planck constant), came into effect on 20 May 2019. Minor adjustments were also made to the values of these constants. In addition to the base units, there are 22 coherent derived units, including radian (rad) for plane angle, steradian (sr) for solid angle, hertz (Hz) for frequency, newton (N) for force, pascal (Pa) for pressure, joule (J) for energy, work, and amount of heat, and watt (W) for power and radiant flux. Recommended practice is to avoid combinations such as N/mm², MN/m² being preferred.(kg) for mass; mole (mol) for amount of substance; second (s) for time; kelvin (K) for temperature; ampere (A) for electric current; and candela (cd) for luminous intensity. New SI unit definitions, based upon the values of the universal constants of nature (also termed the fundamental physical constants: the Avogadro constant, the Boltzmann constant, and the Planck constant), came into effect on 20 May 2019. Minor adjustments were also made to the values of these constants. In addition to the base units, there are 22 coherent derived units, including radian (rad) for plane angle, steradian (sr) for solid angle, hertz (Hz) for frequency, newton (N) for force, pascal (Pa) for pressure, joule (J) for energy, work, and amount of heat, and watt (W) for power and radiant flux. Recommended practice is to avoid combinations such as N/mm², MN/m² being preferred. （国际单位制，Le Système international d\\\'unités）目前美国除外，在科学和工程中几乎是普遍使用的标准单位制。SI的最终参考是国际度量衡局出版的小册子，通常称为BIPM SI小册子。有七个基本单位：米（符号m）表示长度；质量为千克（kg）；物质量的摩尔（mol）；时间为秒；开尔文（K）表示温度；电流为安培（A）；而坎德拉（cd）表示发光强度。新的国际单位制定义于2019年5月20日生效，该定义基于自然界的普遍常数（也称为基本物理常数：阿伏伽德罗常数、玻尔兹曼常数和普朗克常数）。这些常数的值也进行了少量调整。除了基本单位外，还有22个相干导出单位，包括平面角的弧度（rad）、立体角的斯特拉迪安（sr）、频率的赫兹（Hz）、力的牛顿（N）、压力的帕斯卡（Pa）、能量、功和热量的焦耳（J）以及功率和辐射通量的瓦特（W）。建议的做法是避免N/mm²、MN/m²等组合。 |
| Feather key | 滑键 |
A parallel key fastened in either the shaft or in the hub of a member sliding on it. When fastened in the shaft, it must be long enough to hold or drive the sliding member in any of its positions on the shaft. When in the sliding member the key need only be as long as the hub. 一种平行键，固定在轴上或在其上滑动的构件的轮毂上。当固定在轴上时，其长度必须足以将滑动构件固定或驱动在轴上的任何位置。当处于滑动构件中时，键只需与轮毂一样长。 |
| Alpha iron | 阿尔法铁 |
The body-centered cubic form of pure iron, stable below 910 °C (1670 °F). 纯铁的体心立方形式，在910°C(1670°F)以下稳定。 |
| Fatigue wear | 疲劳磨损 |
Wear of a solid surface caused by fracture arising from material fatigue. 由材料疲劳引起的断裂引起的固体表面磨损。 |
| Nonlinear behavior | 非线性行为 |
A fastener or joint system is said to exhibit nonlinear behavior when the relationship between the External load on the joint and deformation of the parts is nonlinear, or when the relationship between increasing Preload and deformation is nonlinear. 当接头上的外部载荷与零件变形之间的关系是非线性的，或者当增加的预载荷与变形之间的联系是非线性的时，可以说紧固件或接头系统表现出非线性行为。 |
| Oxygen probe | 定氧测头 |
An atmosphere-monitoring device that electronically measures the difference between the partial pressure of oxygen in a furnace or furnace supply atmosphere and the external air. 一种大气监测装置，以电子方式测量熔炉或熔炉供应大气中的氧分压与外部空气之间的差值。 |
| Wire rope | 钢丝绳 |
A type of cable formed from individual strands of wire with a helical twist. 一种线缆，由具有螺旋扭曲的单独的线股形成。 |
| International Bureau of Weights and Measures | 国际度量衡局IBWM |
(BIPM, Bureau International des Poids et Mesures) The intergovernmental organization which has the mandate to provide the basis for a single, coherent system of measurements, traceable to the International System of Units. （BIPM，国际计量局）政府间组织，其任务是为可追溯到国际单位制的单一、一致的计量系统提供基础。 |
| Corrosive wear | 腐蚀磨损 |
Wear in which chemical or electrochemical reaction with the environment is significant. 与环境发生显着化学或电化学反应的磨损。 |
| Lockbolt | 锁紧螺栓 |
A fastener which bears a superficial resemblance to a bolt, but which engages a collar (instead of a nut) with annular grooves (instead of threads). The collar is swaged over the grooves on the male fastener to develop preload. 表面上类似于螺栓的紧固件，但与环槽（而不是螺纹）接合的轴环（而不是螺母）。套环在阳紧固件上的凹槽上锻造，以产生预紧力。 |
| Actual value | 实际价值 |
The output of a plant that is being controlled, i.e. the controlled variable. Not directly accessible by the control system, as it can only be measured by a sensor which may distort the measurement. 受控设备的输出，即受控变量。控制系统不能直接访问，因为它只能由可能会扭曲测量结果的传感器测量。 |
| Combined dimensioning | 组合尺寸标注 |
The use of chain dimensioning and parallel dimensioning on the same engineering drawing. 在同一工程图上使用链式尺寸标注和平行标注。 |
| Plane strain | 平面应变 |
The stress condition in linear-elastic fracture mechanics in which there is zero strain in a direction normal to both the axis of applied tensile stress and the direction of crack growth (i.e., parallel to the crack front); most nearly achieved in loading thick plates along a direction parallel to the plate surface. Under plane-strain conditions, the plane of fracture instability is normal to the axis of the principal tensile stress. 线弹性断裂力学中的应力条件，其中在垂直于施加拉应力轴和裂纹扩展方向（即平行于裂纹前沿）的方向上存在零应变；最接近于沿平行于板表面的方向加载厚板。在平面应变条件下，断裂失稳平面垂直于主拉应力轴。 |
| Collapse load (Unit N) | 毁坏荷载（单位N） |
The applied load at which a structure becomes a mechanism owing to the formation of sufficient plastic hinges for collapse to occur. 由于形成足够的塑性铰链以发生坍塌，结构成为机制的施加载荷。 |
| Computer-aided design (CAD) | 计算机辅助设计（CAD） |
Generally, design and calculations performed by computer; more specifically, the use of computer graphics and models to communicate design concepts. Computer-aided design and computer-aided manufacturing (CAD/CAM) is where component dimensions resulting from CAD are passed by electronic means directly to machines for manufacture. 一般由计算机进行设计和计算，更具体地说，使用计算机图形和模型来传达设计概念。计算机辅助设计和计算机辅助制造（CAD/CAM）是由CAD产生的组件尺寸通过电子方式直接传递到机器进行制造。 |
| Milling | 铣削 |
A machining process, typically for metals and plastics, in which a multi-tooth rotary cutter removes material to produce flat or profiled surfaces, slots, grooves, etc. Milling is a machining process in which metal is removed by a rotating multiple-tooth cutter; each tooth removes a small amount of metal with each revolution of the spindle. Because both workpiece and cutter can be moved in more than one direction at the same time, surfaces having almost any orientation can be machined. 一种加工工艺，通常用于金属和塑料，其中多齿旋转刀具去除材料以产生平坦或异形表面、槽、槽等。金属由旋转多齿刀具去除；主轴每转一圈，每个齿都会去除少量金属。因为工件和刀具可以同时在多个方向上移动，所以几乎可以加工任何方向的表面。 |
| Bioenergy | 生物能源 |
1. Energy derived from materials such as purpose-grown energy crops, including sugar cane, maize, wheat, and rice, as well as wood, straw, and animal waste, including sewage, manure, and animal litter. 2. A term sometimes used to cover biomass and biofuels together. 1.来自特定种植的能源作物（包括甘蔗、玉米、小麦和大米）以及木材、稻草和动物粪便（包括污水、粪便和动物垃圾）等材料的能源。2.有时用于同时涵盖生物质和生物燃料的术语。 |
| Pressure loss (Unit Pa) | 压力损失（单位Pa） |
The loss in stagnation pressure in internal flow due to wall friction and minor losses in fittings. 壁面摩擦引起的内部流动停滞压力损失和配件的微小损失。 |
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