| 词或词组 | 中文 | 英文解释中文解释 |
|---|---|---|
| Combined heat and power plant | 热电联产电厂 |
(CHP plant, COGEN, cogeneration plant, total-energy plant) A plant for the simultaneous production of more than one useful form of energy from the same energy source, such as process heat and electric power. In the arrangement shown, partially expanded steam is extracted from the steam turbine and used to produce process heat. （CHP工厂、COGEN、热电联产工厂、总能源工厂）从同一能源（如过程热能和电力）同时生产一种以上有用能源的工厂。在所示的布置中，部分膨胀的蒸汽从蒸汽轮机中提取并用于产生过程热量。 |
| Solenoid | 螺线管 |
A coil of electrically-conducting wire wrapped around a metal core, typically iron, to produce a magnetic field and hence a force on the core when an electric current passes through the coil. Solenoids are widely used to produce linear movement to actuate valves (solenoid valves) and other devices. 绕在金属芯（通常为铁）上的导线线圈，当电流通过线圈时产生磁场，从而在芯上产生力。电磁阀广泛用于产生线性运动以驱动阀（电磁阀）和其他装置。 |
| Kinetic energy | 动能 |
Energy that an object possesses because it is in motion. It is the energy given to an object to set it in motion. On impact, it is converted into other forms of energy such as strain, heat, sound and light. 物体因运动而拥有的能量。它是赋予物体使其运动的能量。撞击时，它被转换成其他形式的能量，如应变、热、声和光。 |
| T-bolt | T型螺栓 |
A threaded bolt having a square or rectangular end which fits into the T slot of a machine table for clamping workpieces. 一种带有方形或矩形端头的螺栓，可嵌入机床工作台的T形槽中，用于夹紧工件。 |
| Breaking load | 断裂载荷 |
The maximum load (or force) applied to a test specimen or structural member loaded to rupture. 施加到加载到破裂的试样或结构构件上的最大载荷（或力）。 |
| Engine | 引擎 |
A machine that converts energy, including the chemical energy in a fuel and electrical energy, into mechanical energy, usually to produce power delivered through a rotating shaft or thrust. Examples include internal-combustion engines, gas and steam turbines, rocket engines, electric, hydraulic and pneumatic motors. 一种将能量（包括燃料中的化学能和电能）转换为机械能的机器，通常通过旋转轴或推力产生动力。例子包括内燃机、燃气轮机和蒸汽轮机、火箭发动机、电动、液压和气动马达。 |
| Toothed gearing | 齿轮传动 |
In principle, friction between circular discs in tangential contact could be used to transmit rotation and power between shafts, but the power level would be very limited and the velocity ratio affected by slip. To make the drive positive, gear wheels are used instead in which teeth extend above and below the diameters (the pitch-circle diameters) of discs in ideal rolling contact. The diagram shows the nomenclature for spur gears, the simplest type of gearing between parallel shafts, which are cylindrical in shape with straight teeth parallel to the axis of rotation. 原则上，切向接触的圆盘之间的摩擦可用于在轴之间传递旋转和动力，但动力水平非常有限，速比受滑动的影响。为了使驱动积极，使用齿轮代替，齿轮中的齿延伸到理想滚动接触的圆盘直径（节圆直径）的上方和下方。该图显示了直齿轮的名称，这是平行轴之间最简单的齿轮传动类型，其形状为圆柱形，直齿平行于旋转轴。 |
| Precision | 精确 |
The closeness of agreement between the results of individual replicated measurements or tests. The standard deviation of the error of measurement may be used as a measure of “imprecision.” 单个重复测量或测试结果之间的一致性。测量误差的标准偏差可用作“不精确性”的度量 |
| Yield point (Unit Pa) | 屈服点（单位Pa） |
The first stress in a material, usually less than the maximum attainable stress, at which an increase in strain occurs without an increase in stress. Only certain metals—those which exhibit a localized, heterogeneous type of transition from elastic to plastic deformation—produce a yield point. If there is a decrease in stress after yielding, a distinction may be made between upper and lower yield points. The load at which a sudden drop in the flow curve occurs is called the upper yield point. The constant load shown on the flow curve is the lower yield point. (yield strength, yield stress, Rel, Rel) The stress at which the onset of permanent (plastic) deformation (yielding) occurs in a body under increasing loading. In some materials, a yield-point phenomenon occurs in which stress falls on initial yielding and plastic deformation continues without increase in stress as strain increases further. The yield criterion is the combination of normal and shear stresses which produces yielding under multiaxial loading. 材料中的第一应力，通常小于可达到的最大应力，在该应力下应变增加而应力不增加。只有某些金属——表现出从弹性变形到塑性变形的局部、非均匀类型的金属——才会产生屈服点。如果屈服后应力降低，可区分上屈服点和下屈服点。流量曲线突然下降时的荷载称为上屈服点。流量曲线上显示的恒定载荷为较低屈服点。（屈服强度，屈服应力，Rel）在不断增加的载荷下，物体发生永久（塑性）变形（屈服）时的应力。在某些材料中，会出现屈服点现象，即应力在初始屈服时下降，随着应变进一步增加，塑性变形继续，而应力没有增加。屈服准则是在多轴载荷下产生屈服的正应力和剪应力的组合。 |
| Principal stress (normal) | 主应力（正常） |
The maximum or minimum value of the normal stressat a point in a plane considered with respect to all possible orientations of the considered plane. On such principal planes the shear stress is zero. There are three principal stresses on three mutually perpendicular planes. The state of stress at a point may be: (1) uniaxial, a state of stress in which two of the three principal stresses are zero; (2) biaxial, a state of stress in which only one of the three principal stresses is zero; or (3) triaxial, a state of stress in which none of the principal stresses is zero. Multiaxial stress refers to either biaxial or triaxial stress. 相对于所考虑平面的所有可能方向，所考虑平面中某点处的法向应力的最大值或最小值。在这样的主平面上，剪切应力为零。在三个相互垂直的平面上有三个主应力。一点的应力状态可以是：（1）单轴，三个主应力中的两个为零的应力；（2）双轴，三个主应力中只有一个为零的应力状态；或（3）三轴，即主应力均不为零的应力状态。多轴应力是指双轴或三轴应力。 |
| Air-cooled engine | 风冷发动机 |
An internal-combustion engine directly cooled by airflow, rather than by water flowing through the engine block being cooled by a radiator. 一种由气流直接冷却的内燃机，而不是通过流经发动机缸体的水被散热器冷却。 |
| constitutive equation | 本构方程 |
(constitutive relation) 1. In solid mechanics or fluid mechanics, an algebraic or numerical relation for the dependency of stress on deformation, strain, strain rate, temperature, etc. in a material. In solid mechanics such a relation is sometimes called an equation of state. Simple linear examples include Hooke’s law and Newton’s viscosity law. 2. In heat transfer, a relation, such as Fourier’s law of heat conduction, connecting heat flux with temperature gradient. （本构关系）1.在固体力学或流体力学中，应力与材料的变形、应变、应变率、温度等之间的代数或数值关系。在固体力学中，这种关系有时称为状态方程。简单的线性例子包括胡克定律和牛顿粘度定律。2.在传热学中，将热流与温度梯度联系起来的一种关系，如傅立叶热传导定律。 |
| Flattening test | 压扁试验 |
This term as applied to tubing refers to a method of testing a section of tubing by flattening it until the inside walls are parallel and separated by a given distanceusually equal to three times the wall thickness for seamless tubes and five times the wall thickness for lap-welded tubes. Boiler tubes subjected to this test should show no cracks or flaws. The flattening test applied to rivets, consists in flattening a rivet head while hot to a diameter equal to 21⁄2 times the diameter of the shank or body of the rivet. Good rivet steel must not crack at the edges of the flattened head. 该术语适用于管材，是指通过压扁管材直至内壁平行并隔开给定距离（通常等于无缝钢管壁厚的三倍，搭接焊管壁厚的五倍）来测试管材截面的方法。进行该试验的锅炉管应无裂纹或缺陷。适用于铆钉的压扁试验包括在热态下压扁铆钉头，使其直径等于铆钉柄或铆钉体直径的21⁄2倍。良好的铆钉钢不得在扁平头部边缘开裂。 |
| Clearance | 间距 |
(Unit m or μm) 1. The distance (if any) between mating components in an assembly. 2. The distance between two moving parts, or a moving part and stationary part, in a machine (e.g. the gap between a piston and a cylinder head). 3. With threads, the major clearance is the distance between the design form at the root of an internal thread and the crest of its mating external thread; the minor clearance is the corresponding dimension between the crest of an internal thread and the root of the external thread. （单位m或μm）1.装配体中配合组件之间的距离（如果有）。2.机器中两个运动部件之间的距离，或运动部件和静止部件之间的距离（例如活塞和气缸盖之间的间隙）。3.带螺纹时，主要间隙是内螺纹根部的设计形状与其配合的外螺纹牙顶之间的距离；小间隙是内螺纹牙顶和外螺纹牙根之间的对应尺寸。 |
| Fastener identification marking | 紧固件识别标记 |
A stamp, paint, or other permanent identifier that may include manufacturer information and applicable grade markings for certification purposes. 印章、油漆或其他永久性标识符，其中可能包括制造商信息和用于认证的适用等级标记。 |
| Square thread | 方螺纹 |
A form of screw thread in which the cross–section of the thread forms a square, making the width of the thread equal to the space between the threads. 螺纹的一种形式，螺纹的横截面形成正方形，使螺纹的宽度等于螺纹之间的间距。 |
| Q-factor | 品质因素 |
(quality factor, sharpness of resonance) A non-dimensional parameter that describes, for a given resonant mode, the sharpness of the peak in the frequency response of a lightly-damped linear oscillator: Q = ωRES/Δω where ωRES is the resonance frequency and Δω is the half-power bandwidth of the resonance. It is inversely related to the damping such that a broad peak corresponds to high damping and a narrow peak to low damping. （品质因数，共振尖锐度）一个无量纲参数，用于描述给定共振模式下，轻阻尼线性振荡器频率响应峰值的尖锐度：Q=ωRES/Δω，其中ωRES是共振频率，Δω是共振的半功率带宽。它与阻尼成反比，因此宽峰值对应于高阻尼，窄峰值对应于低阻尼。 |
| 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。 |
| Resistance factor | 阻力系数 |
Probabilistic factor representing the uncertainties in the designer’s estimate of the strength of a shear joint. Used in Load and resistance factor design. 概率系数，表示设计人员对剪切接头强度估计的不确定性。用于载荷和阻力系数设计。 |
| Controlled cooling | 控制冷却 |
Cooling from an elevated temperature in a predetermined manner, to avoid hardening, cracking, or internal damage, or to produce desired microstructure or mechanical properties. 以预定方式从升高的温度冷却，以避免硬化、开裂或内部损坏，或产生所需的微观结构或机械性能。 |
| Sharp-notch strength | 锐缺口强度 |
The notch tensile strength measured using specimens with very small notch root radii (approaching the limit for machining capability); values of sharp-notch strength usually depend on notch root radius. 使用缺口根部半径非常小（接近加工能力极限）的试样测量的缺口抗拉强度；锐缺口强度值通常取决于缺口根部半径。 |
| 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。 |
| Effective crack size (ae) | 有效裂纹尺寸（ae） |
The physical crack size augmented for the effects of cracking plastic deformation. Sometimes the effective crack size is calculated from a measured value of a physical crack size plus a calculated value of a plastic-zone adjustment. A preferred method for calculation of effective crack size compares compliance from the secant of a load-deflection trace with the elastic compliance from a calibration for the type of specimen. 由于裂纹塑性变形的影响，物理裂纹尺寸增大。有时，根据物理裂纹尺寸的测量值加上塑性区调整的计算值来计算有效裂纹尺寸。计算有效裂纹尺寸的首选方法是将载荷-挠度轨迹正割的柔度与试样类型校准的弹性柔度进行比较。 |
| 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。 |
| 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。 |
| Diaphragm compressor | 隔膜式压缩机 |
A machine in which compression is achieved by the reciprocating motion of a flexible membrane of metal, plastic, or elastomeric material. This arrangement is ideally suited to pumping high-purity, toxic, or explosive gases. A similar machine incorporating check valves is a self-priming positive-displacement pump (diaphragm pump, membrane pump). 通过金属、塑料或弹性材料的柔性薄膜的往复运动实现压缩的机器。这种布置非常适合泵送高纯度、有毒或爆炸性气体。装有止回阀的类似机器是自吸容积泵（隔膜泵、隔膜泵）。 |
| Heat-treatable alloy | 可热处理合金 |
An alloy that can be hardened by heat treatment. 一种可以通过热处理硬化的合金。 |
| Grub screw | 平头螺丝 |
A short headless screw with a recess at one end to receive a screw driver or key. 一种短的无头螺钉，一端有一个凹槽，用于安装螺丝刀或钥匙。 |
| Isothermal annealing | 等温退火 |
Austenitizing a ferrous alloy and then cooling to and holding at a temperature at which austenite transforms to a relatively soft ferrite carbide aggregate. 将铁合金奥氏体化，然后冷却至奥氏体转变为相对软的铁素体碳化物集合体的温度并保持该温度。 |
| Modulus of rupture | 断裂模量 |
Nominal stress at fracture in a bend test or torsion test. In bending, modulus of rupture is the bending moment at fracture divided by the section modulus. In torsion, modulus of rupture is the torque at fracture divided by the polar section modulus. 弯曲试验或扭转试验中的标称断裂应力。在弯曲中，断裂模量是断裂时的弯矩除以截面模量。在扭转中，断裂模量是断裂时的扭矩除以极截面模量。 |
| Aspect ratio | 纵横比 |
The ratio of the longest to the shortest dimension of a shape or object e.g. the chord-to-thickness ratio of an aerofoil or the span-to-chord ratio of a wing. 形状或物体的最长与最短尺寸之比，例如机翼的弦厚比或机翼的翼展弦比。 |
| Mohs hardness test | 莫氏硬度测试 |
A scratch hardness test for determining comparative hardness using 10 standard minerals—from talc (the softest) to diamond (the hardest). 刮擦硬度测试，用于使用从滑石（最软）到钻石（最硬）的10种标准矿物测定比较硬度。 |
| Adhesive joint | 粘合接头 |
The point or area in which two structures are held together by an adhesive. 两个结构通过粘合剂粘合在一起的点或区域。 |
| Constant-force spring | 恒力弹簧 |
A spring that has the same restoring force regardless of displacement. The most common type takes the form of a coiled strip that, owing to tight coiling during manufacture, is pre-stressed (a steel measuring tape is an example). The uncoiling force is approximately constant as the change of curvature of the strip is approximately constant. Not to be confused with a clockwork spring from which power can be obtained. 无论位移如何，具有相同恢复力的弹簧。最常见的类型是卷绕带，由于制造过程中的紧密卷绕，该卷绕带是预应力的（钢卷尺就是一个例子）。随着带材曲率的变化近似恒定，开卷力近似恒定。不要与可获得动力的发条弹簧混淆。 |
| Continuous-type furnace | 连续式炉 |
A furnace used for heat treating materials that progress continuously through the furnace, entering one door and being discharged from another. See belt furnac, direct-fired tunnel-type furnac, rotary retort furnace, shaker-hearth furnace. 一种用于热处理材料的炉子，该炉子连续通过炉子，进入一个门并从另一个门排出。参见带式高炉、直燃隧道式高炉、旋转罐式炉、振动炉。 |
| 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）。 |
| Scratching | 刮擦 |
In tribology, the mechanical removal or displacement, or both, of material from a surface by the action of abrasive particles or protuberances sliding across the surfaces. 在摩擦学中，通过在表面上滑动的磨粒或突起的作用，材料从表面上的机械移除或移位，或两者兼而有之。 |
| Flat head | 平头 |
Flat top surface and a conical bearing surface. 平顶表面和锥形轴承表面。 |
| Torsional stress | 扭转应力 |
The shear stress on a transverse cross section resulting from a twisting action. 扭转作用在横截面上产生的剪切应力。 |
| Crack-extension force (G) | 裂纹扩展力（G） |
The elastic energy per unit of new separation area that would be made available at the front of an ideal crack in an elastic solid during a virtual increment of forward crack extension. 在向前裂纹扩展的虚拟增量期间，在弹性固体中理想裂纹的前端可获得的每单位新分离面积的弹性能量。 |
| 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。 |
| Volume (Unit m³) | 体积（单位m³） |
The amount of space occupied by a specified mass of substance or by an object. 一定质量的物质或物体占据的空间量。 |
| Thermal efficiency | 热效率 |
The ratio, for a heat engine or thermodynamic cycle, of the net work output to the net heat input into the system. 对于热机或热力循环，净功输出与系统净热输入的比率。 |
| Gage length | 标距 |
The original length of the portion of a specimen over which strain, change of length, or other characteristics are determined. 确定应变、长度变化或其他特性的试样部分的原始长度。 |
| Thermodynamics laws | 热力学定律 |
The zeroth, first, second, and third laws of thermodynamics. 热力学第零、第一、第二和第三定律。 |
| Stiffness | 刚度 |
(1) The ability of a metal or shape to resist elastic deflection.(2) The rate of stress increase with respect to the rate of increase in strain induced in the metal or shape; the greater the stress required to produce a given strain, the stiffer the material is said to be. （1）金属或形状抵抗弹性变形的能力。（2）所述应力增加速率相对于在所述金属或形状中诱导的应变增加速率；产生给定应变所需的应力越大，材料就越硬。 |
| Knoop hardness test | 努氏硬度试验 |
An indentation-hardness test using calibrated machines to force a rhombic-based pyramidal diamond indenter having specified edge angles, under specified conditions, into the surface of the material under test and to measure the long diagonal after removal of the load. An indentation hardness test in which the indenter is an elongated diamond pyramid that gives an impression in the form of a parallelogram, in which the longer diagonal is about seven times the shorter. Used for studies of anisotropy in solid materials. 使用校准机器进行的一种压痕硬度试验，在规定条件下，将具有规定边缘角的菱形棱锥金刚石压头压入受试材料表面，并在移除荷载后测量长对角线。其中压头是一个细长的菱形棱锥，以平行四边形的形式给出压痕，其中较长的对角线约为较短的七倍。用于研究固体材料的各向异性。 |
| 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。 |
| Torsion bar | 扭杆 |
A metal bar designed to act as an elastic spring when torque is applied. 当施加扭矩时用作弹性弹簧的金属棒。 |
| Relaxed stress | 松弛应力 |
The initial stress minus the remaining stress at a given time during a stress-relaxation test. 在应力松弛试验期间，初始应力减去给定时间的剩余应力。 |
| Power | 力能 |
The rate of doing work or of producing or consuming energy. The unit of power is the watt, W, where 1 W = 1 N m/s. 做功或产生或消耗能量的速度。功率单位为瓦特，W，其中1W=1N m/s。 |
| Tensile stress (Unit Pa) | 拉应力（单位Pa） |
A stress that causes two parts of an elastic body, on either side of a typical stress plane, to pull apart. A stress that tends to stretch a component, or local region of a component, when under load. In simple tension it results from the applied axial load, but tensile stresses occur in bending, torsion and other forms of loading. 一种应力，使弹性体的两个部分在典型应力平面的任一侧分离。在负载下，倾向于拉伸部件或部件局部区域的应力。在简单拉伸中，它由施加的轴向载荷产生，但拉伸应力发生在弯曲、扭转和其他形式的载荷中。 |
| Tyre | 轮胎 |
A flexible ring-shaped cover mounted on a wheel rim that supports the weight of a vehicle, such as a motor vehicle, aircraft, or bicycle, and transmits power and torque to a road surface. Some pneumatic tyres are inflated directly, others have a separate inner tube that is inflated. For certain applications, solid tyres are used. 车轮罩安装在轮辋上的柔性环形罩，用于支撑车辆（如机动车、飞机或自行车）的重量，并将动力和扭矩传递到路面。有些充气轮胎是直接充气的，有些轮胎有单独的内胎充气。对于某些应用，使用实心轮胎。 |
| Effective length of a bolt | 螺栓的有效长度 |
The grip length plus some portion of the bolt (often one-half of the thickness of the nuts) which lies within the nut(s) plus some portion (often one-half the thickness) of the head. 握持长度加上位于螺母内的螺栓的某些部分（通常是螺母厚度的二分之一）加上头部的某些部分（通常是厚度的二分之一）。 |
| Slip joint | 滑动接头 |
A mechanical connection which allows limited endwise relative movement of two components such as pipes, rods, and ducts. 一种机械连接，允许两个部件（如管道、杆和管道）进行有限的轴向相对运动。 |
| Frequency | 频率 |
(temporal frequency, f) (Unit Hz) The number of cycles per second in an oscillation or the repetition rate for a cyclic process. （时间频率，f）（单位Hz）振荡中每秒的周期数或循环过程的重复率。 |
| Coining | 压印 |
A forging operation, employing a closely-fitting punch and die from which no metal is allowed to escape, in which the surface pattern on the punch and die is imprinted on the blank. 一种锻造操作，采用紧密配合的凸模和模具，不允许金属逸出，其中凸模和模具上的表面图案印在坯料上。 |
| Observed value | 观测值 |
The particular value of a characteristic determined as a result of a test or measurement. 作为测试或测量结果确定的特性的特定值。 |
| Starting torque (Unit N.m) | 起动扭矩（单位：N.m） |
The torque developed by a motor at zero rotational speed in order to initiate rotation of the applied load. 电机在零转速下产生的扭矩，以启动所施加负载的旋转。 |
| Abrasion | 磨损 |
The removal of surface material by the scratching action of hard particles, either deliberately (abrasive papers, abrasive cleaning, abrasive machining) or as a consequence of operation (wear). 通过硬质颗粒的刮擦作用去除表面材料，可以是故意的（砂纸、研磨清洁、研磨加工），也可以是操作的结果（磨损）。 |
| Maximum stress-intensity factor (Kmax) | 最大应力强度因子（Kmax） |
The maximum value of the stress-intensity factorin a fatigue cycle. 疲劳循环中应力强度因子的最大值。 |
| Stress-intensity factor | 应力强度因子 |
A scaling factor, usually denoted by the symbol K, used in linear-elastic fracture mechanics to describe the intensification of applied stress at the tip of a crack of known size and shape. At the onset of rapid crack propagation in any structure containing a crack, the factor is called the critical stress-intensity factor, or the fracture toughness. 一种标度因子，通常用符号K表示，在线弹性断裂力学中用于描述已知尺寸和形状的裂纹尖端施加应力的增强。在任何含有裂纹的结构中，裂纹快速扩展开始时，该因子称为临界应力强度因子，或断裂韧性。 |
| Threshold stress for stress-corrosion cracking (σth) | 应力腐蚀开裂阈值应力（σth） |
An experimentally determined critical gross-section stress below which stress-corrosion cracking will not occur under specified test conditions. 实验确定的临界总截面应力，低于该应力，在规定的试验条件下不会发生应力腐蚀开裂。 |
| Free joint | 万向节 |
The joint on a robot arm and wrist that causes the greatest end-effector movement when a specified force is applied to the end effector, i.e. that has the lowest stiffness with regard to the force. 机器人手臂和手腕上的关节，当指定的力施加到末端执行器时，会导致末端执行器的最大运动，即相对于力具有最低刚度。 |
| Flange rotation | 法兰转角 |
Angular distortion of a flange under the influence of bolt and reaction forces. Measured with respect to the center of the cross section of the flange. 法兰在螺栓和反作用力影响下的角度变形。相对于法兰横截面的中心测量。 |
| Newton’s law of viscosity | 牛顿内摩擦定律 |
The shear stress between two parallel layers of fluid is proportional to the velocity of one relative to that of the other, and inversely proportional to the distance between them. The constant of proportionality is the dynamic viscosity μ. For a Newtonian fluid μ is independent of pressure gradient, shear stress, and strain, but may change with temperature and pressure. 两个平行流体层之间的剪切应力与其中一层相对于另一层的速度成正比，与它们之间的距离成反比。比例常数是动态粘度μ。对于牛顿流体，μ与压力梯度、剪切应力和应变无关，但可能随温度和压力而变化。 |
| Stress distribution | 应力分布 |
The manner in which tensile, compressive, and shear stresses are distributed within a loaded body, indicated by loci of constant stress. 拉应力、压应力和剪应力在受载物体内的分布方式，由恒定应力轨迹表示。 |
| Fretting fatigue | 微动疲劳 |
Fatigue fracture that initiate at a surface area where fretting has occurred. The progressive damage to a solid surface that arises from fretting. 在发生微动的表面区域开始的疲劳断裂。由微动引起的对固体表面的渐进性损坏。 |
| Coarse threads | 粗螺纹 |
Threads with relatively large separation between corresponding points on the threads. 螺纹上相应点之间的间距相对较大的螺纹。 |
| 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。 |
| Stress-intensity calibration | 应力强度校准 |
A mathematical expression, based on empirical or analytical results, that relates the stress-intensity factor to load and crack length for a specific specimen planar geometry. Also known as Kcalibration. 基于经验或分析结果的数学表达式，该表达式将特定试样平面几何形状的应力强度因子与载荷和裂纹长度联系起来。也称为K校准。 |
| Clevis joint | U形接头 |
A joint formed by two parallel cantilever beams pressed upon a component between the beams. 由两个平行悬臂梁压在梁之间的部件上形成的接头。 |
| 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。 |
| Austenitic stainless steels | 奥氏体不锈钢 |
Austenitic stainless steels are non-magnetic. They contain significant additions of chromium (16–30%), but have the austenite (FCC) crystal structure, stabilized by the addition of nickel in the composition range 6–20%. Carbon content ranges from about 0.03 to 0.15%. The ‘18–8’ stainless steels containing approximately 18% chromium and 8% nickel are typical of the class. Austenitic stainless steels have high strength and corrosion resistance even at elevated temperatures, good ductility, good low-temperature properties, and good weldability. Used for aircraft and transport equipment, cutlery, chemical and food-processing equipment, surgical instruments, and cryogenic vessels. 奥氏体不锈钢是非磁性的。它们含有显着添加的铬（16–30%），但具有奥氏体（FCC）晶体结构，通过在6–20%的成分范围内添加镍来稳定。碳含量范围约为0.03至0.15%。含有大约18%铬和8%镍的“18-8”不锈钢是该级别的典型不锈钢。奥氏体不锈钢即使在高温下也具有高强度和耐腐蚀性，良好的延展性，良好的低温性能和良好的焊接性。用于飞机和运输设备、餐具、化学和食品加工设备、手术器械和低温容器。 |
| Vernier | 游标 |
A short auxiliary scale that slides along the main instrument scale to permit more accurate fractional reading of the least main division of the main scale. 一种短辅助刻度，沿主仪表刻度滑动，以便更准确地读取主刻度的最小主刻度。 |
| Dynamic load (Unit N) | 动态负载（单位N） |
1. Loading of a component or structure by a moving object whose point of application changes with time, e.g. the live load of a train passing over a bridge. 2. A load applied to a particular part of a component or structure in a short time interval. 1. 应用点随时间变化的移动物体对部件或结构的加载，例如通过桥梁的火车的活荷载。2. 在短时间内施加到部件或结构的特定部分的载荷。 |
| Critical crack length (Unit m) | 临界裂纹长度（单位米） |
The crack length at which a given stress applied to a body will result in crack propagation and fracture. 施加到物体上的给定应力将导致裂纹扩展和断裂的裂纹长度。 |
| Stress equalizing | 应力均衡 |
A low-temperature heat treatment used to balance stresses in cold-worked material without an appreciable decrease in the mechanical strength produced by cold working. 一种低温热处理，用于平衡冷加工材料中的应力，而不会明显降低冷加工产生的机械强度。 |
| Graphitic carbon | 石墨碳 |
Free carbon in steel or cast iron. 钢或铸铁中的游离碳。 |
| Shear lip | 剪切唇 |
A narrow, slanting ridge along the edge of a fracture surface. The term sometimes also denotes a narrow, often crescent-shaped, fibrous region at the edge of a fracture that is otherwise of the cleavage type, even though this fibrous region is in the same plane as the rest of the fracture surface. 沿断裂面边缘的狭窄倾斜脊。该术语有时还表示断裂边缘处的狭窄、通常为新月形的纤维区域，否则为解理型，即使该纤维区域与断裂表面的其余部分位于同一平面内。 |
| Statistic | 统计 |
A summary value calculated from the observed values in a sample. 根据样本中的观察值计算得出的汇总值。 |
| Tension testing | 张力测试 |
A method of determining the behavior of materials subjected to uniaxial loading, which tends to stretch the metal. A longitudinal specimen of known length and diameter is gripped at both ends and stretched at a slow, controlled rate until rupture occurs. Also known as tensile testing. 一种确定材料在单轴载荷下的行为的方法，这种载荷倾向于拉伸金属。将已知长度和直径的纵向试样夹持在两端，并以缓慢、受控的速率拉伸，直到发生断裂。也称为拉伸测试。 |
| Acicular ferrite | 针状铁素体 |
A highly substructured non-equiaxed ferrite that forms upon continuous cooling by a mixed diffusion and shear mode of transformation that begins at a temperature slightly higher than the temperature transformation range for upper bainite. It is distinguished from bainite in that it has a limited amount of carbon available; thus, there is only a small amount of carbide present. Ferrite crystallite growing, apparently, as in the course of bainitic transformation. It has a lath-like shape and an increased dislocation 一种高度亚结构的非等轴铁素体，在连续冷却时通过混合扩散和剪切相变模式形成，其开始温度略高于上贝氏体的温度转变范围。它与贝氏体的区别在于它的碳含量有限。因此，仅存在少量碳化物。显然，铁素体微晶在贝氏体转变过程中生长。它具有板条状的形状和增加的位错。 |
| 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。 |
| Stress-relaxation curve | 应力松弛曲线 |
A plot of the remaining, or relaxed, stress in a stress-relaxation test as a function of time. The relaxed stress equals the initial stress minus the remaining stress. Also known as a stress-time curve. 应力松弛试验中剩余应力或松弛应力随时间变化的曲线图。松弛应力等于初始应力减去剩余应力。也称为应力-时间曲线。 |
| Stress difference (Unit Pa) | 应力差（单位Pa） |
The algebraic difference between the largest and least principal stresses in a loaded body, equal to twice the greatest shear stress in the system. For σ1 > σ2 > σ3, it is given by (σ1 − σ3). 载荷体中最大和最小主应力之间的代数差，等于系统中最大剪应力的两倍。由（σ1− σ3).，可得σ1＞σ2＞σ3。 |
| 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。 |
| Pitch angle (Unit °) | 俯仰角（单位°） |
For a bevel gear, the angle between the axis and the pitch-cone generator. 对于锥齿轮，轴与节锥生成器之间的角度。 |
| Millimetre of water | 毫米水柱 |
A non-SI unit of pressure equal to the pressure exerted by a vertical column of water 1 mm high. Approximately equal to 9.81 Pa. 一种非SI压力单位，等于1毫米高的垂直水柱施加的压力。大约等于9.81Pa。 |
| Lubricant | 润滑剂 |
Any substance interposed between two surfaces for the purpose of reducing the friction or wear between them. 为了减少两个表面之间的摩擦或磨损而置于两个表面间的任何物质。 |
| Fog quenching | 雾淬 |
Quenching in a fine vapor or mist. 在细蒸汽或薄雾中淬火。 |
| Auxetic materials | 拉胀材料 |
Those man-made materials for which Poisson’s ratio is negative, so that the cross section expands when subjected to a longitudinal tensile stress and contracts when subjected to a longitudinal compressive stress. 泊松比为负的人造材料，其横截面在受到纵向拉应力时会膨胀，在受到纵向压应力时会收缩。 |
| Grain refiner | 晶粒细化机 |
A material added to a molten metal to induce a finer-than-normal grain size in the final structure. 添加到熔融金属中以在最终结构中产生比正常晶粒尺寸更细的材料。 |
| 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。 |
| Corrosion | 腐蚀 |
The deterioration of an exposed metal surface due to electrochemical oxidation with its surroundings. In the oxidation reaction, metal atoms give up electrons which are transferred to form another chemical species by a reduction reaction, usually with hydrogen and/or oxygen. A common example is the formation of the iron oxide rust Fe(OH)3 on iron or steel in moist air or water. Rust breaks away easily, exposing fresh iron to the atmosphere, whereas the corrosion product of some metals forms an adherent layer that prevents further oxidation reaction at fresh metal, an effect known as passivation. Examples include aluminium oxide on aluminium, chromium oxide on chromium, chromium oxide on alloys containing chromium such as stainless steels, and the patina formed on copper and zinc. Corrosion protection takes many forms. Good design to avoid crevices and stress is important. In some situations, substances known as inhibitors may be added to the environment to decrease its corrosiveness. The electrochemical nature of corrosion results in some metals having a greater tendency for oxidation than others. Zinc has a stronger tendency than iron and this is made use of in galvanizing. This is one example of cathodic protection, in which one metal is connected electrically to a more reactive metal, called a sacrificial anode, that oxidizes by giving up electrons and so protects the first metal. Coatings may be used to resist corrosion. Paints, plating, and diffusion coatings are the most common and the electrochemical process of anodizing is used to deliberately form a passive layer of oxide on aluminium alloys. Material selection plays a major role. For example, stainless steels with their high chromium content are widely used in corrosive environments. 暴露的金属表面由于与周围环境的电化学氧化而劣化。在氧化反应中，金属原子放弃电子，这些电子通过还原反应（通常与氢和/或氧）转移形成另一种化学物质。一个常见的例子是在潮湿的空气或水中在铁或钢上形成氧化铁锈Fe(OH)3。铁锈很容易脱落，将新鲜铁暴露在大气中，而一些金属的腐蚀产物形成一层粘附层，防止新鲜金属发生进一步的氧化反应，这种效果称为钝化。实例包括铝上的氧化铝、铬上的氧化铬、含铬合金上的氧化铬如不锈钢，以及铜和锌上形成的铜绿。腐蚀防护有多种形式。避免裂缝和应力的良好设计非常重要。在某些情况下，可以向环境中添加称为抑制剂的物质，以降低其腐蚀性。腐蚀的电化学性质导致一些金属比其他金属具有更大的氧化倾向。锌比铁具有更强的倾向性，这可用于镀锌。这是阴极保护的一个例子，其中一种金属与活性更强的金属（称为牺牲阳极）电连接，牺牲阳极通过释放电子进行氧化，从而保护第一种金属。涂层可用于抗腐蚀。油漆、电镀和扩散涂层是最常见的，阳极氧化的电化学过程用于有意在铝合金上形成一层钝化氧化物。材料选择起着重要作用。例如，铬含量高的不锈钢广泛用于腐蚀性环境。 |
| Joint diagrams | 接合处关系图 |
Mathematical diagrams which illustrate the forces on and deflections of fasteners and joint members. 说明紧固件和连接件上的力和变形的数学图。 |
| Shear stress (Unit Pa) | 剪应力（单位Pa） |
(1) A stress that exists when parallel planes in metal crystals slide across each other. (2) The stress component tangential to the plane on which the forces act. Also known as tangential stress. (shearing stress, tangential stress, τ) 1. The stress which acts parallel to any plane within a solid material. It can arise due to a bending moment, a shear force, or torque applied to the body. 2. The stress corresponding to velocity gradients within a flowing viscous fluid. （剪应力，切向应力，τ）（1）当金属晶体中的平行平面彼此滑动时存在的应力。（2）与力作用平面相切的应力分量。也称为切向应力。1.平行于固体材料内任何平面的应力。它可能是由于施加在身体上的弯矩、剪力或扭矩引起的。2.对应于流动粘性流体内的速度梯度的应力。 |
| Initial stress | 初始应力 |
The stress produced by strain in a specimen immediately on achieving the given constant-strain conditions in a stress-relaxation test before stress-relaxation occurs. Sometimes referred to as instantaneous stress. 在应力松弛发生之前，在应力松弛试验中达到给定的恒定应变条件时，试样立即应变所产生的应力。有时称为瞬时压力。 |
| Active vibration suppression | 主动振动抑制 |
The reduction of undesirable vibration in components by feedback control. 通过反馈控制减少部件中的不良振动。 |
| Modulus of elasticity (E) | 弹性模量（E） |
The measure of rigidity or stiffness of a metal; the ratio of stress, below the proportional limit, to the corresponding strain. In terms of the stress-strain diagram, the modulus of elasticity is the slope of the stress-strain curve in the range of linear proportionality of stress to strain. 金属的刚度或刚度的量度；低于比例极限的应力与相应应变之比。根据应力应变图，弹性模量是应力应变曲线在应力应变线性比例范围内的斜率。 |
| Erosion | 侵蚀 |
Progressive loss of original material from a solid surface due to mechanical interaction between that surface and a fluid, a multicomponent fluid, or impinging liquid or solid particles. 由于固体表面与流体、多组分流体或撞击液体或固体颗粒之间的机械相互作用，原始材料从固体表面逐渐损失。 |
| 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。 |
| 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。 |
| 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。 |
| Intergranular fracture | 沿晶破裂 |
Brittle fracture of a metal in which the fracture is between the grains, or crystals, that form the metal. Also called intercrystalline fracture. 金属的脆性断裂，断裂位于形成金属的晶粒或晶体之间。又称晶间破裂。 |
| Elastic recovery | 弹性恢复 |
Amount the dimension of a stressed elastic material returns to its original (unstressed) dimension on release of an applied load. In hardness testing, the shortening of the original dimensions of the indentation upon release of the applied load. 在释放施加的载荷时，受应力弹性材料的尺寸恢复到其原始（无应力）尺寸的量。在硬度测试中，当释放所施加的载荷时，压痕的原始尺寸缩短。 |
| 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。 |
| Freezing point | 冰点 |
The temperature at which a substance changes phase (or state) from liquid to solid. The freezing point for most substances increases as pressure increases. The reverse process, from solid to liquid, is melting; melting point is the same as freezing point. 物质从液态变为固态的温度。大多数物质的冰点随着压力的增加而增加。从固体到液体的逆过程是熔化；熔点与凝固点相同。 |
| Crossed threads | 交叉螺纹 |
When the axis of a nut offered up to a bolt is not aligned with the axis of a bolt (or a screw to a threaded member), it may be possible for the threads to engage incorrectly and even for the nut or screw to advance a turn or more, but ultimately the misaligned threads become locked together. Forcing the nut in such circumstances may irretrievably damage the threads on both. 当提供给螺栓的螺母的轴线与螺栓（或螺纹构件的螺钉）的轴线不对齐时，螺纹可能会错误接合，甚至螺母或螺钉会提前一圈或更多，但最终未对齐的螺纹会锁定在一起。在这种情况下强行拧入螺母可能会对两侧的螺纹造成无法修复的损坏。 |
| Fine pitch | 细牙螺纹 |
Fine pitch threads are often used within the automotive industry. They are more easily tapped into harder materials and have less tendency to loosen. 细螺距螺纹通常用于汽车行业。它们更容易被敲入较硬的材料中，并且不太容易松动。 |
| Densimeter | 密度计 |
An instrument used to determine the density or relative density of a solid or liquid. 用于测定固体或液体的密度或相对密度的仪器。 |
| Vickers hardness test | 维氏硬度测试 |
An indentation hardness test employing a 136° diamond pyramid indenter (Vickers) and variable loads, enabling the use of one hardness scale for all ranges of hardness—from very soft lead to tungsten carbide. Also know as diamond pyramid hardness test. 采用136°金刚石棱锥压头（维氏硬度计）和可变载荷的压痕硬度测试，能够对从极软铅到碳化钨的所有硬度范围使用一个硬度标度。也称为钻石金字塔硬度测试。 |
| Tensometer | 拉力计 |
A bench-top device, used to perform tension and compression tests. 用于进行拉伸和压缩试验的台式装置。 |
| Double aging | 双级时效 |
Employment of two different aging treatments to control the type of precipitate formed from a supersaturated matrix in order to obtain the desired properties. The first aging treatment, sometimes referred to as intermediate or stabilizing, is usually carried out at higher temperature than the second. 采用两种不同的时效处理来控制由过饱和基质形成的沉淀物类型，以获得所需的性能。第一次时效处理，有时称为中间处理或稳定处理，通常在比第二次更高的温度下进行。 |
| Abrasive wear | 磨料磨损 |
The removal or displacement of material from a surface when hard particles slide or roll across the surface under pressure. The particles may be loose or may be part of another surface in contact with the surface being worn. Contrast with adhesive wear. 当硬质颗粒在压力下在表面上滑动或滚动时，材料从表面上的去除或位移。颗粒可能是松散的或可能是与被磨损表面接触的另一个表面的一部分。与粘着磨损形成对比。 |
| Centre of pressure | 压力中心 |
1. The location, on an aerofoil or other body that develops lift, of the resultant lift force. 2. The location, on a surface submerged in a liquid, of the resultant force due to the pressure acting on the surface. Because hydrostatic pressure increases with depth, the centre of pressure is generally below the centroid of the surface. 1.在产生升力的机翼或其他物体上，合成升力的位置。2.在浸没在液体中的表面上，由于作用在表面上的压力而产生的合力的位置。由于静水压力随深度增加，压力中心通常低于表面质心。 |
| Hexagon nut | 六角螺母 |
A nut having six sides and shaped like a hexagon. 六边形的螺母。 |
| Auxiliary power unit (APU) | 辅助动力装置（APU） |
In aircraft–gas–turbine applications, a small gas turbine used to provide start-up power, electrical and hydraulic power, and compressed air for cabin ventilation. In other applications, an APU may be a gas turbine or internal-combustion engine used to provide emergency power. 在飞机-燃气轮机应用中，小型燃气轮机用于提供启动动力、电力和液压动力以及用于机舱通风的压缩空气。在其他应用中，APU可以是用于提供应急动力的燃气轮机或内燃机。 |
| Autonomous energy system | 自主能源系统 |
(stand-alone energy system) A sole source of electricity, usually small-scale, for applications remote from a grid, especially with energy storage in the system. Hydroelectric, photovoltaic, wind-power and other renewable systems are well suited to stand-alone applications. （独立能源系统）一种唯一的电力来源，通常是小规模的，用于远离电网的应用，尤其是系统中的能量存储。水电、光伏、风力和其他可再生能源系统非常适合独立应用。 |
| Shear strain rate(Unit 1/s) | 剪切应变率（单位1/s） |
In the deformation of solids, the rate at which shear strain is applied in a test or changes with time in a loaded component or structure. 在固体变形中，在试验中施加剪切应变的速率，或在加载部件或结构中随时间变化的速率。 |
| Relaxation rate | 松弛率 |
The absolute value of the slope of a stress-relaxation curve at a given time. 给定时间应力松弛曲线斜率的绝对值。 |
| 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。 |
| Hypereutectic alloy | 过共晶合金 |
In an alloy system exhibiting a eutectic, any alloy whose composition has an excess of alloying element compared with the eutectic composition, and whose equilibrium microstructure contains some eutectic structure. 在呈现共晶的合金系统中，任何合金，其组成与共晶组成相比具有过量的合金元素，并且其平衡微观结构包含一些共晶结构。 |
| Calorie | 卡路里 |
(cal, gram calorie, small calorie) An obsolete (i.e. non-SI) unit of energy equal to 4.186 8 J. It is the amount of energy needed to raise the temperature of 1 gram of pure airfree water from 14.5°C to 15.5°C at standard atmospheric pressure. （卡，克热量，小热量）一种已被淘汰的（即非SI）能量单位，等于4.1868J。它是在标准大气压力下将1克纯无空气水的温度从14.5℃升高到15.5℃所需的能量。 |
| 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。 |
| Equation, long form | 方程，长格式 |
An equation which relates the torque applied to a bolt to the preload created in it, and involves fastener geometry and the coefficient of friction between mating surfaces. A theoretical equation based on rigid body mechanics and the assumption that the geometry of the fastener is perfectly described by blueprint dimensions. 将施加在螺栓上的扭矩与螺栓中产生的预载荷联系起来的方程，该方程涉及紧固件几何形状和配合面之间的摩擦系数。基于刚体力学和紧固件几何结构由蓝图尺寸完美描述的假设的理论方程。 |
| Torsion | 扭矩 |
A twisting deformation of a solid body about an axis in which lines that were initially parallel to the axis become helices. The twisting of an object about an axis due to an applied couple (torque). 一种固体绕轴的扭转变形，在该变形中，最初平行于轴的线变成螺旋线。由于施加的力偶（扭矩），物体绕轴扭曲。 |
| Thermodynamic properties | 热力学性质 |
Temperature, pressure, and the intensive properties that define the state of a working fluid: specific internal energy, specific enthalpy and specific entropy. 温度、压力和定义工作流体状态的密集属性：比内能、比焓和比熵。 |
| Gearbox | 变速箱 |
A mechanism consisting of meshing gears which transmit power and torque to an output shaft from an input shaft directly connected to an engine. The mechanism is normally contained within a casing filled with lubricating oil. The diagram shows a simple four-speed sliding-mesh gearbox in which gears with different numbers of teeth are slid along parallel splined shafts within the gearbox to mesh with each other and change the ratio of output to input speed (gear ratio). 一种由啮合齿轮组成的机构，将动力和扭矩从直接连接到发动机的输入轴传递到输出轴。该机构通常包含在充满润滑油的外壳内。示例一个简单的四速滑动啮合齿轮箱，其中具有不同齿数的齿轮沿着齿轮箱内的平行花键轴滑动，以相互啮合并改变输出与输入速度的比率（齿轮比）。 |
| Computer numerical control (CNC) | 计算机数控（CNC） |
A term relating to machine tools in which the movements of a tool and/or the workpiece are controlled by computer. 与机床相关的术语，其中工具和/或工件的运动由计算机控制。 |
| Atomizing humidifier | 雾化加湿器 |
A humidifier that functions by spraying fine droplets of water into an airstream. 一种加湿器，通过将细小的水滴喷射到气流中来发挥作用。 |
| Threaded fastener | 螺纹紧固件 |
Studs, bolts, and screws of all sorts, with associated nuts. One of the most interesting, complex, useful—and frustrating—components yet devised. 各种螺柱、螺栓和螺钉，以及相关的螺母。 |
| Superheating | 过热 |
Heating above the temperature at which an equilibrium phase transformation should occur without actually obtaining the transformation. 在不实际获得相变的情况下，加热到应发生平衡相变的温度以上。 |
| 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。 |
| Angle of thread | 螺纹角度 |
The included angle between the sides forming the groove of the screw thread. 形成螺纹凹槽的边之间的夹角。 |
| Fracture toughness | 断裂韧性 |
A generic term for measures of resistance to extension of a crack. The term is sometimes restricted to results of fracture mechanics tests, which are directly applicable in fracture control. However, the term commonly includes results from simple tests of notched or precracked specimens not based on fracture mechanics analysis. Results from tests of the latter type are often useful for fracture control, based on either service experience or empirical correlations with fracture mechanics tests. 裂纹扩展阻力测量的通用术语。该术语有时仅限于断裂力学试验的结果，这些结果直接适用于断裂控制。该术语通常包括非基于断裂力学分析的切口或预裂纹试样的简单试验结果。基于使用经验或与断裂力学试验的经验相关性，后一类试验的结果通常有助于断裂控制。 |
| Prevailing torque | 有效扭矩 |
Torque required to run a nut down against the joint when some obstruction, such as a plastic insert in the threads, or a noncircular thread, or other, has been introduced to help the fastener resist vibration loosening. Prevailing torque, unlike normal torque on a nut or bolt, is not proportional to the Preload in the fastener. 当引入了一些障碍物（如螺纹中的塑料插件或非圆螺纹或其他障碍物）以帮助紧固件抵抗振动松动时，将螺母向下压靠接头所需的扭矩。与螺母或螺栓上的正常扭矩不同，主要扭矩与紧固件中的预载不成比例。 |
| 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。 |
| 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。 |
| Circlip | 卡簧 |
(snap ring) An external or internal retaining ring that locates parts of circular cross section in an axial direction. It consists of an incomplete ring, with holes on either side of the gap, that may be expanded by a plier-like tool to pass into a groove in a shaft or contracted to pass into a groove in a bore. （卡环）在轴向定位圆形横截面部分的外部或内部保持环。它由一个不完整的环组成，在间隙的任一侧都有孔，可以通过钳形工具将其扩展以进入轴中的凹槽或收缩以进入孔中的凹槽。 |
| 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。 |
| Preload adjustments | 预载调整 |
Preloads may be applied directly by axial loading or indirectly by turning of the nut or bolt. When preload is applied by turning of nuts or bolts, a torsion load component is added to the desired axial bolt load. 预载荷可通过轴向载荷直接施加，或通过转动螺母或螺栓间接施加。当通过转动螺母或螺栓施加预载荷时，扭转载荷分量被添加到所需的轴向螺栓载荷中。 |
| Ideal gas laws | 理想气体定律 |
The law relating pressure, temperature and volume of an ideal (perfect) gas pV = mRT, where R is the gas constant. The law implies that at constant temperature T, the product of pressure p and volume V is constant (Boyle’s law), and at constant pressure, the volume is proportional to the temperature (Charles’ law). 与理想（完美）气体的压力、温度和体积相关的定律pV=mRT，其中R是气体常数。该定律意味着在恒定温度T下，压力p和体积V的乘积是恒定的（波义耳定律），而在恒定压力下，体积与温度成正比（查尔斯定律）。 |
| Butt joint | 对接接头 |
The end-to-end joining of two plates either by welding or by overlapping plates that are bolted or riveted. 通过焊接或通过螺栓或铆接的重叠板将两块板端对端连接。 |
| 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. |
| 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）。 |
| Two-dimensional flow | 二维流 |
A fluid flow in which the velocity at any time depends upon two spatial coordinates, such as the radial and axial locations in developing pipe flow. 一种流体流动，其中任何时候的速度取决于两个空间坐标，如发展中的管道流中的径向和轴向位置。 |
| Offset modulus | 补偿模量 |
The ratio of the offset yield stress to the extension at the offset point (plastics). 偏移屈服应力与偏移点（塑料）处延伸的比率。 |
| Breaks | 断裂 |
Creases or ridges usually in “untempered” or in aged material where the yield point has been exceeded. Depending on the origin of the break, it may be termed a cross break, a coil break, an edge break, or a sticker break. 通常在“未回火”或超过屈服点的老化材料中出现折痕或隆起。根据断裂的起源，它可能被称为交叉断裂、线圈断裂、边缘断裂或贴纸断裂。 |
| Recrystallization temperature | 再结晶温度 |
The approximate minimum temperature at which complete recrystallization of a cold-worked metal occurs within a specified time. 冷加工金属在规定时间内发生完全再结晶的近似最低温度。 |
| Thread milling | 螺纹铣削 |
Thread milling is a method of cutting screw threads with a milling cutter in a thread mill. Thread milling cutters are either single form or multiple form and are used in either conventional or planetary thread mills. 螺纹铣削是在螺纹铣刀中用铣刀切削螺纹的一种方法。螺纹铣刀为单形或多形，用于传统或行星式螺纹铣刀。 |
| Microindentation hardness test | 显微压痕硬度测试 |
Hardness test using a calibrated machine to force a diamond indenter of specific geometry, under a test load of 1 to 1000 gramforce, into the surface of the test material and to measure the diagonal or diagonals of the indentation optically. 使用校准机器进行硬度试验，以在1至1000克力的试验载荷下，将特定几何形状的金刚石压头压入试验材料表面，并光学测量压痕的对角线。 |
| Shoulder joint | 轴肩关节 |
The second joint on an articulated robot, which has a horizontal axis and is analogous to the human shoulder. 关节机器人上的第二个关节，具有水平轴，类似于人的肩膀。 |
| Austempered steels | 等温钢 |
Medium to high carbon steels with improved mechanical properties as a result of austempering. After heating to between 800° and 900°C to form the austenite phase, they are quenched to, and held at, just above the martensite transformation range (between 260° and 370°C) to form bainite, before cooling further. Austempering of ductile cast irons results in a microstructure of bainite and spheroidal graphite. Austempered ductile irons have excellent toughness and wear properties. 由于等温淬火，机械性能得到改善的中高碳钢。在加热到800°和900°C之间形成奥氏体相后，将它们淬火并保持在略高于马氏体转变范围（260°和370°C之间）以形成贝氏体，然后进一步冷却。球墨铸铁的等温淬火导致贝氏体和球状石墨的微观结构。等温淬火球墨铸铁具有优异的韧性和耐磨性。 |
| 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。 |
| Pressure chamber | 压力室 |
A chamber in which components or devices can be subjected to high or low fluid (liquid or gas) pressure. 部件或装置可承受高或低流体（液体或气体）压力的腔室。 |
| Fitted bolt | 装配螺栓 |
A bolt with a plain unthreaded portion immediately beneath the head. 一种螺栓，其头部正下方有一个普通的无螺纹部分。 |
| Push rod | 推杆 |
A rod which opens and closes a valve via a valve rocker in an overhead-valve piston engine. The rod is actuated by a camshaft located in the crankcase. 在顶置气门活塞发动机中，通过气门摇臂打开和关闭气门的杆。连杆由曲轴箱中的凸轮轴驱动。 |
| Carbon restoration | 碳修复 |
Replacing the carbon lost in the surface layer from previous processing by carburizing this layer to substantially the original carbon level. Sometimes called recarburizing. 通过将该层渗碳到基本上原始的碳水平来替换先前处理中在表面层中损失的碳。有时称为再碳化。 |
| Tribology | 摩擦学 |
The science and technology concerned with interacting surfaces in relative motion. 与相对运动中相互作用的表面有关的科学和技术。 |
| ABS polymer | ABS聚合物 |
A class of thermoplastic co-polymer consisting of the three monomers acrylonitrile, butadiene and styrene that has improved properties (particularly toughness) over the individual constituents. 一类由丙烯腈、丁二烯和苯乙烯三种单体组成的热塑性共聚物，其性能（特别是韧性）优于单个成分。 |
| Nanomanufacturing | 纳米制造 |
1. The manufacture of nanoscale materials. 2. The manufacture of components or devices that have critical dimensions of order 1 nm. 1.纳米材料的制造。2.具有1nm级临界尺寸的部件或装置的制造。 |
| Degradation of energy | 能源退化 |
Conversion of energy into forms of lower usefulness due to irreversibilities in energy transfer and conversion processes. The increase in entropy can be regarded as a measure of the degradation of energy. 由于能量转移和转换过程中的不可逆性，将能量转换为低效形式。熵的增加可以看作是能量退化的量度。 |
| 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。 |
| 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。 |
| 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。 |
| Compression stroke | 压缩冲程 |
The stroke in a reciprocating compressor or engine during which the working fluid is compressed. 往复式压缩机或发动机中工作流体被压缩的冲程。 |
| Square | 正方 |
1. A regular quadrilateral, i.e. a polygon with four equal sides and four right angles. 2. An instrument to check angles of internal and external surfaces and flatness. 1.正四边形，即具有四条等边和四个直角的多边形。2.一种检查内外表面角度和平面度的仪器。 |
| Design pressure (Unit Pa) | 设计压力（单位Pa） |
The greatest pressure that a closed container is expected to experience under normal operating conditions. 密闭容器在正常操作条件下预期承受的最大压力。 |
| Absorber | 吸收器 |
1. An auxiliary vibratory system that favourably modifies the vibration characteristics of a main system. 2. Part of an absorption refrigeration system in which the refrigerant is absorbed by a transport medium. 3. The absorber plate is the receiver of a concentrating solar collector where the radiation is absorbed. 1.一种辅助振动系统，可有利地改变主系统的振动特性。2.吸收式制冷系统的一部分，其中制冷剂被传输介质吸收。3.吸收板是吸收辐射的聚光太阳能集热器的接收器。 |
| Working load (Unit N) | 工作负荷（单位：N） |
The tension in a bolt in use; tension produced by a combination of Residual preload and a portion (usually) of any External load. The Joint diagram is usually used to predict the approximate working load a fastener will see in service. The load under which a component or structure is designed to operate under normal conditions. 螺栓在使用中的张力；残余预载荷和部分（通常）任何外部载荷的组合产生的张力。连接图通常用于预测紧固件在使用中的近似工作载荷。部件或结构设计为在正常条件下运行的荷载。 |
| Physical properties | 物理性质 |
Properties of a material the determination of which does not involve the deformation or destruction of the specimen—for example, density, electrical conductivity, coefficient of thermal expansion, magnetic permeability, and lattice parameter. Does not include chemical reactivity or the properties more appropriately regarded as mechanical properties. 不涉及试样变形或破坏的材料特性，例如密度、电导率、热膨胀系数、磁导率和晶格参数。不包括化学反应性或更适当地视为机械的性质。 |
| Orange peel | 橘皮 |
A surface roughening in the form of a pebble-grained pattern where a metal of unusually coarse grain is stressed beyond its elastic limit. Also known as pebbles and alligator skin. 一种以卵石颗粒图案形式出现的粗糙化表面，其中晶粒异常粗的金属受到的应力超过其弹性极限。也称为卵石和鳄鱼皮。 |
| Actuating system | 驱动系统 |
A system in which an electrical, pneumatic or hydraulic input supplied to an actuator produces force, torque, or displacement, usually in a controlled way. 一种系统，其中提供给执行器的电气、气动或液压输入通常以受控方式产生力、扭矩或位移。 |
| Achme thread | Achme螺纹 |
A screw thread having an included angle of 29° and largely used for feed screws on machine tools. 一种夹角为29°的螺纹，主要用于机床上的进给丝杠。 |
| 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。 |
| Deposit gauge | 沉积量计 |
(deposition gauge) An instrument employed in air pollution studies for measuring the amount of pollutant deposited on a given area in a given time under given conditions. （沉降计）在空气污染研究中使用的仪器，用于测量在给定条件下在给定时间内沉积在给定区域上的污染物量。 |
| Absolute manometer | 绝对压力计 |
A manometer that measures absolute pressure, i.e. pressure measured relative to a perfect vacuum. Absolute pressure cannot be negative. 测量绝对压力的压力计，即相对于完美真空测量的压力。绝对压力不能为负。 |
| Materials science | 材料科学 |
The study of the properties, behaviour, and application of solid substances such as metals, ceramics, glasses, polymers, composites, biomaterials, and semiconductors, at all scales from the atomic to the macroscopic. The topic has its origins in metallurgy. 研究金属、陶瓷、玻璃、聚合物、复合材料、生物材料和半导体等固体物质的特性、行为和应用，涵盖从原子到宏观的所有范围。起源于冶金学。 |
| Drift pin | 冲头 |
A round tapered steel pin used to align rivet holes so that the rivet will pass through the holes easily. 用于对齐铆钉孔的圆形锥形钢销，以便铆钉轻松穿过孔。 |
| 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。 |
| Initial preload | 初始预载 |
The tension created in a single bolt as it is tightened. Will usually be modified by subsequent assembly operations or by in-service loads and conditions. 拧紧单个螺栓时产生的张力。通常会通过后续的装配操作或在役负载和条件进行修改。 |
| 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。 |
| 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。 |
| 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。 |
| Plane-stress fracture toughness (Kc) | 平面应力断裂韧性（Kc） |
In linear-elastic fracture mechanics, the value of the crack-extension resistance at the instability condition determined from the tangency between the R-curve and the critical crack-extension force curve of the specimen. 在线弹性断裂力学中，由试样的R曲线和临界裂纹扩展力曲线之间的切线确定的不稳定条件下裂纹扩展阻力的值。 |
| Biomechanics | 生物力学 |
The application of mechanical-engineering principles, including thermodynamics, fluid mechanics, and solid mechanics together with materials engineering, to biological systems. 机械工程原理（包括热力学、流体力学和固体力学以及材料工程）在生物系统中的应用。 |
| Radioactive heat (Unit J) | 放射性热（单位J） |
Thermal energy released from the nucleus of an atom such as uranium235 by fission due to the absorption of a neutron. Heat is also produced by radioactive decay. 铀235等原子核因吸收中子而裂变释放的热能。放射性衰变也会产生热量。 |
| Batch furnace | 间歇式炉 |
A furnace used to heat treat a single load at a time. Batch-type furnaces are necessary for large parts such as heavy forgings and are preferred for complex alloy grades requiring long cycles. 用于一次热处理单个负载的炉子。对于重型锻件等大型零件，间歇式炉是必需的，对于需要长周期的复杂合金牌号来说是首选。 |
| 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。 |
| Seal | 密封件 |
A component which controls or prevents leakage of fluids into or out of parts of a machine. 控制或防止流体流入或流出机器部件的部件。 |
| Self-locking nut | 自锁螺母 |
A nut with an inherent locking action which minimizes loosening due to vibration. A self-locking screw locks itself in place without the need for a separate selflocking nut or lock washer. 一种具有固有锁定作用的螺母，可将振动引起的松动降至最低。自锁螺钉将自身锁定到位，无需单独的自锁工件或锁紧垫圈。 |
| Median fatigue strength at N cycles | N次循环的中位疲劳强度 |
An estimate of the stress level at which 50% of the population would survive N cycles. The estimate is derived from a particular point of the fatigue life distribution, because there is no test procedure by which a frequency distribution of fatigue strengths at Ncycles can be directly observed. 估计50%的量在N个周期内生存的压力水平。该估计值来自疲劳寿命分布的一个特定点，因为没有试验程序可以直接观察N次循环疲劳强度的频率分布。 |
| Indentation hardness | 压痕硬度 |
The resistance of a material to indentation as determined by hardness testing. The indenter, which may be spherical or diamond shaped, is pressed into the surface of a metal under specified load for a given time. (Unit Pa or, non-SI, kgf/mm²) A measurement of hardness taken by means of an indenter, pressed into a material by a load, which makes a permanent impression. The hardness is given by the load divided by the projected (sometimes surface) area of the indentation. Plasticity theory shows that the hardness is about 2.5–3 times the uniaxial yield stress. 通过硬度测试确定的材料抗压痕的能力。压头可以是球形或菱形，在规定的载荷下压入金属表面一段时间。（单位Pa或，非国际单位制，kgf/mm²）通过压头测量硬度，压入材料，形成永久压痕。硬度由载荷除以压痕的投影（有时是表面）面积得出。塑性理论表明，硬度约为单轴屈服应力的2.5–3倍。 |
| Stress factor | 应力因子 |
A calibration constant used in ultrasonic measurement of bolt stress or strain. It is the ratio between the change in ultrasonic transit time caused by the change in length of the fastener, under load, to the total change in transit time. 用于螺栓应力或应变超声波测量的校准常数。它是由紧固件长度变化引起的超声波传输时间变化与总传输时间变化之间的比率。 |
| Stainless steels | 不锈钢 |
Iron-base alloys that are highly resistant to corrosion in many environments. The predominant alloying element is chromium, which, like iron at room temperature, has BCC crystal structure. Corrosion resistance by passivation is achieved by the formation of chromium oxide on the steel surface. Nickel, which has FCC crystal structure, is another important addition for some steels. Other additions used to enhance properties include manganese, molybdenum, niobium, and titanium. There are several classes of stainless steel. 在许多环境中具有高度耐腐蚀性的铁基合金。主要的合金元素是铬，与室温下的铁一样，铬具有BCC晶体结构。钝化抗腐蚀性是通过在钢表面形成氧化铬来实现的。具有FCC晶体结构的镍是某些钢的另一种重要添加剂。其他用于增强性能的添加剂包括锰、钼、铌和钛。不锈钢的种类有好几种。 |
| Tightness | 紧密度 |
A measure of the mass leak rate from a gasketed joint. 垫圈接头质量泄漏率的测量值。 |
| Graphitization | 石墨化 |
Formation of graphite in iron or steel. Where graphite is formed during solidification, the phenomenon is called primary graphitization; where formed later by heat treatment, secondary graphitization. 在铁或钢中形成石墨。在凝固过程中形成石墨的现象称为一次石墨化；后来通过热处理，形成二次石墨化。 |
| Temperature (Unit K or °C) | 温度（单位K或°C） |
A quantitative measure of the molecular kinetic energy of a substance and so how hot or cold it is. 物质分子动能的定量量度，以及它的冷热程度。 |
| Clutch | 离合器 |
A device for connecting and disconnecting rotating shafts, for example between an engine and a gearbox. 一种用于连接和断开旋转轴的装置，例如在发动机和变速箱之间。 |
| Wrought iron | 锻铁 |
A highly ductile (but anisotropic) type of iron containing elongated slag fibres that resulted from the method of manufacture in which excess carbon in pig iron was burnt and worked out. The yield strength is some 200 MPa, tensile strength 320 MPa, and reduction of area on a 50-mm gauge length up to 35%. Now replaced by steel. 一种高韧性（但各向异性）的铁，含有细长的矿渣纤维，由生铁中多余的碳燃烧和加工的制造方法产生。屈服强度约为200MPa，抗拉强度为320MPa，50mm标距上的面积缩减率高达35%。现在被钢所取代。 |
| 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。 |
| Quench cracking | 淬火开裂 |
Fracture of a metal during quenching from elevated temperature. Most frequently observed in hardened carbon steel, alloy steel, or tool steel parts of high hardness and low toughness. Cracks often emanate from fillets, holes, corners, or other stress raisers and result from high stresses due to the volume changes accompanying transformation to martensite. 高温淬火时金属断裂。在高硬度和低韧性的硬化碳钢、合金钢或工具钢零件中最常见。裂纹通常来自圆角、孔、角部或其他应力集中区，并由伴随马氏体转变的体积变化引起的高应力引起。 |
| 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。 |
| Plane-strain fracture toughness (KIc) | 平面应变断裂韧性（KIc） |
The crack extension resistance under conditions of crack-tip plane strain. 裂纹尖端平面应变条件下的裂纹扩展阻力。 |
| Screw pair | 螺旋副 |
Two links connected together to form a kinematic pair, in which the contacting surfaces are screw threads, so that their relative motion consists of rotation and sliding. 两个连杆连接在一起形成运动副，其中接触面为螺纹，因此它们的相对运动包括旋转和滑动。 |
| 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。 |
| Cavitation-resistance inducer | 抗气蚀诱导剂 |
An axial-flow pump used upstream of a main pump in order to prevent cavitation in the latter by increasing the inlet head. 在主泵上游使用的轴流泵，通过增加进口压头防止主泵出现气穴。 |
| Fracture surface | 断裂面 |
The irregular surface produced when a piece of metal is broken. 一块金属破碎时产生的不规则表面。 |
| 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。 |
| Centripetal | 向心力 |
Acting or moving in a direction towards the axis of rotation. 在朝向旋转轴的方向上起作用或移动。 |
| Endurance | 耐力 |
The capacity of a material to withstand repeated application of stress. 材料承受反复施加应力的能力。 |
| Total carbon | 总碳 |
The sum of the free and combined carbon (including carbon in solution) in a ferrous alloy. 铁合金中游离碳和结合碳（包括溶液中的碳）的总和。 |
| 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。 |
| 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。 |
| Austenite stabilization | 奥氏体稳定化 |
Decrease, in comparison to a continuous cooling, in the amount of martensite occurring from austenite when cooling is interrupted at a temperature between Ms and Mf. This can be explained by the relaxation of stresses induced in the austenite by martensite crystals occurring before the interruption. The relaxation, in turn, leads to the dislocation rearrangement and their interaction with martensite/austenite interfaces, which makes the interfaces immobile. 与连续冷却相比，当在Ms和Mf之间的温度中断冷却时，从奥氏体中产生的马氏体的量减少。这可以通过中断前发生的马氏体晶体在奥氏体中引起的应力松弛来解释。反过来，松弛导致位错重排及其与马氏体/奥氏体界面的相互作用，这使得界面无法移动。 |
| X–Y recorder | X-Y记录仪 |
A device that plots a graph of a variable y against a variable x, both in the form of voltages. 一种绘制变量y和变量x的图形的设备，两者都以伏特数的形式。 |
| Intense quenching | 强烈淬火 |
Quenching in which the quenching medium is cooling the part at a rate at least two and a half times faster than still water. 淬火，其中淬火介质以比静水快至少两倍半的速度冷却零件。 |
| Laser hardening | 激光硬化 |
A surface-hardening process which uses a laser to quickly heat a surface. Heat conduction into the interior of the part will quickly cool the surface, leaving a shallow martensitic layer. Hardening of steel by a moving CO2 or Nd:YAG laser beam focussed down to a few mm in diameter. A point in the surface of an object is rapidly heated into the austenite range and then rapidly cooled to form tempered martensite. 一种使用激光快速加热表面的表面硬化工艺。进入零件内部的热传导将快速冷却表面，留下浅马氏体层。通过移动CO2或Nd:YAG激光束使钢硬化，激光束聚焦至直径几毫米。物体表面的一点迅速加热到奥氏体范围，然后迅速冷却，形成回火马氏体。 |
| Decompression chamber | 减压舱 |
A chamber in which ambient-air pressure can be increased to levels found in deep-sea diving. It is used to gradually acclimatize divers back to normal conditions and avoid ‘the bends’. 环境气压可以提高到深海潜水水平的腔室。它用于逐渐使潜水员适应正常条件，避免“弯曲”。 |
| Valve plug | 阀塞 |
A conical or cylindrical plug, in which there are transverse holes, in a valve, such as a plug valve. Flow through the holes occurs when the plug is rotated. 阀门中的圆锥形或圆柱形阀塞，其中有横向孔，如旋塞阀。旋转阀塞时，会发生通过孔的流动 |
| Pre-stress | 预应力 |
To induce stresses into a component or structure before it is subjected to operating loads. 在部件或结构承受操作载荷之前，将应力引入部件或结构。 |
| Rockwell hardness number (HR) | 洛氏硬度值（HR） |
A number derived from the net increase in the depth of impression in a Rockwell hardness test as the load on an indenter is increased from a fixed minor load to a major load and then returned to the minor load. Rockwell hardness numbers are always quoted with a scale symbol representing the penetrator, load, and dial used. 当压头上的载荷从固定的小载荷增加到大载荷，然后返回到小载荷时，洛氏硬度试验中压痕深度的净增加值。洛氏硬度值总是用刻度符号引用，表示所用的穿透器、载荷和刻度盘。 |
| Unit | 单位 |
A numerical indication of the magnitude of a physical quantity. The basic units of mass, length, time, etc. are relative to agreed standards. 物理量大小的数字指示。质量、长度、时间等基本单位与商定的标准相对应。 |
| Interrupted quenching | 间断淬火 |
A quenching procedure in which the workpiece is removed from the first quench at a temperature substantially higher than that of the quenchant and is then subjected to a second quenching system having a different cooling rate than the first. 在该淬火过程中，工件在显著高于淬火剂的温度下从第一次淬火中取出，然后经受具有不同于第一次淬火的冷却速率的第二次淬火系统。 |
| Spalling | 剥落 |
The separation of macroscopic particles from a surface in the form of flakes or chips. 以薄片或碎片形式从表面分离宏观颗粒。 |
| Rated power (Unit kW or hp) | 额定功率（单位：千瓦或马力） |
(rated capacity, rated horsepower) The maximum power output that can be sustained continuously for any power-producing machine or system, such as an engine or a power plant. （额定容量、额定马力）任何发电机器或系统（如发动机或发电厂）可连续维持的最大功率输出。 |
| R-curve/Resistance curve | 阻力曲线 |
In linear-elastic fracture mechanics, a plot of crack-extension resistance as a function of stable crack extension, which is either the difference between the physical crack size, or the effective crack size, and the original crack size. R-curves normally depend on specimen thickness and, for some materials, on temperature and strain rate. An increase in fracture toughness with crack propagation shown by rising plots of toughness vs growing crack length. 在线弹性断裂力学中，作为稳定裂纹扩展函数的裂纹扩展阻力图，即物理裂纹尺寸或有效裂纹尺寸与原始裂纹尺寸之间的差值。R曲线通常取决于试样厚度，对于某些材料，还取决于温度和应变率。是随着裂纹扩展，断裂韧性增加，表现为韧性与扩展裂纹长度的上升曲线。 |
| Turboblower | 涡轮鼓风机 |
A centrifugal or axial compressor or fan. 离心式或轴流式压缩机或风扇。 |
| Gear wheel | 齿轮 |
Any form of toothed wheel, particularly those having conjugate teeth employed in the transmission of motion and power. 任何形式的齿轮，特别是用于传递运动和动力的共轭齿的齿轮。 |
| Design stress (Unit Pa) | 设计应力（单位Pa） |
The greatest allowable stress in a component or structure that will not result in failure under normal operating conditions. 在正常操作条件下不会导致失效的部件或结构中的最大许用应力。 |
| Galling | 磨损 |
An extreme form of adhesive wear, in which large chunks of one part stick to the mating part (during sliding contact). 一种极端形式的粘着磨损，其中一个零件的大块粘在配合零件上（在滑动接触期间）。 |
| Corrosion cell | 腐蚀电池 |
A natural ‘‘battery’’ formed when two metals having different electrical potentials (an Anode and a Cathode) are connected together in the presence of a liquid (the Electrolyte). 当两种具有不同电势的金属（阳极和阴极）在液体（电解质）存在下连接在一起时形成的天然“电池”。 |
| Verification | 检验 |
Checking or testing an instrument to ensure conformance with a specification. 检查或测试仪器以确保符合规范。 |
| 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。 |
| 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。 |
| Anode | 阳极 |
That electrode in a battery or corrosion cell which produces electrons. It is the electrode which is destroyed (corrodes). 电池或腐蚀电池中产生电子的电极。被破坏（腐蚀）的是电极。 |
| Population | 集合 |
The hypothetical collection of all possible test specimens that could be prepared in the specified way from the material under consideration. Also known as universe. 从所考虑的材料中以规定方式制备的所有可能试样的假设集合。也称为体系。 |
| Stress–strain curve | 应力-应变曲线 |
(stress–strain diagram) A plot of stress vs strain for a solid material obtained from a test in which a specimen is loaded in tension, compression, shear, or combinations thereof. Diagrams of true stress vs true strain deviate from those of nominal stress vs nominal strain only at large strains where appreciable changes in cross section of testpieces occur. （应力-应变图）从试验中获得的固体材料的应力与应变图，其中试样在拉伸、压缩、剪切或其组合中加载。只有在试件横截面发生明显变化的大应变下，真实应力与真实应变图与标称应力与标称应变图不同。 |
| Absolute pressure | 绝对压力 |
1. The pressure measured relative to zero pressure (vacuum). 2. Gage pressure plus barometric pressure in the same units. 1.相对于零压力（真空）测量的压力。2.表压加上大气压力的单位相同。 |
| A-basis | A-基础 |
Mechanical property value above which at least 99% of the population of values is expected to fall, with a confidence of 95%. Also called A-allowable. 机械性能值超过该值时，至少99%的值预计会下降，置信度为95%。也被称为A-容许。 |
| Ferritic stainless steels | 铁素体不锈钢 |
Ferritic stainless steels have the ferrite (BCC) crystal structure and contain 10–28% chromium and typically 0.1–0.35% carbon (all in wt%). They are magnetic and can be hardened by cold working. They have good to moderate mechanical properties, good oxidation and corrosion resistance at elevated temperatures, and susceptibility to embrittlement at temperatures between 400 and 540°C. Used for turbine parts, hightemperature valves, automotive exhaust components, and nuclear reactor core components. 铁素体不锈钢具有铁素体（BCC）晶体结构，含有10-28%的铬，通常含有0.1-0.35%的碳（均为重量%）。它们具有磁性，可通过冷加工硬化。它们具有良好至中等的机械性能，在高温下具有良好的抗氧化性和耐腐蚀性，在400至540°C的温度下易脆化。用于涡轮零件、高温阀、汽车排气部件和核反应堆堆芯部件。 |
| British thermal unit (BTU, Btu) | 英热单位（BTU，Btu） |
An obsolete (non-SI) imperial unit of energy defined as the energy required to raise the temperature of one pound of pure water at 68°F by 1°F. The conversion to SI is 1 Btu = 1.055 056 × 103 J. 一种已被淘汰的（非SI）英制能量单位，定义为将68°F的一磅纯水的温度升高1°F所需的能量。转换为SI为1Btu=1.055056×103J。 |
| Compressibility (Unit 1/Pa) | 可压缩性（单位1/Pa） |
A measure of the reduction in volume or increase in density when a substance is subjected to an increase of pressure. It is defined as the reciprocal of the bulk modulus. Liquids and solids are normally considered incompressible, whereas gases are highly compressible. 当物质受到压力增加时体积减少或密度增加的量度。它被定义为体积模量的倒数。液体和固体通常被认为是不可压缩的，而气体是高度可压缩的。 |
| 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。 |
| Transducer | 传感器 |
A device which converts one form of energy into another. An ultrasonic transducer, for example, converts electrical energy into acoustic energy (at ultrasonic frequencies) and vice versa. 将一种形式的能量转换为另一种形式能量的装置。例如，超声换能器将电能转换为声能（在超声频率下），反之亦然。 |
| Microscopic stresses | 微观应力 |
Residual stresses that vary from tension to compression in a distance (presumably approximating the grain size) that is small compared with the gage length in ordinary strain measurements. They are not detectable by dissection methods, but can sometimes be measured from line shift or line broadening in an x-ray diffraction pattern. 与普通应变测量中的标距相比，从拉伸到压缩的距离（大概接近晶粒尺寸）较小的残余应力。它们无法通过解剖方法检测到，但有时可以通过x射线衍射图案中的线位移或线加宽来测量。 |
| Conduit | 导管 |
A hollow object, of metal, plastic, glass, ceramic, etc., which is relatively long compared with its lateral dimensions and through which there is fluid flow. 由金属、塑料、玻璃、陶瓷等制成的中空物体，与其横向尺寸相比相对较长，并且有流体流过。 |
| Atom | 原子 |
The smallest unit of matter that has the properties of a chemical element. The simplest description of an atom (Bohr model) is of a compact nucleus surrounded by one or more orbiting electrons. 具有化学元素性质的最小物质单位。原子的最简单描述（玻尔模型）是由一个或多个轨道电子包围的致密原子核。 |
| Slenderness ratio | 长细比 |
The effective unsupported length of a uniform column divided by the least radius of gyration of the cross-sectional area. 均匀柱的有效无支撑长度除以横截面积的最小回转半径。 |
| Preload accuracy | 预载精度 |
A measure of the precision with which a given tool or procedure creates preload in a bolt when the bolt is tightened. A common torque wrench, for example, is said to produce preload with an accuracy of +30%. The mean preload, however, may not be that which the designer intended, or may not be what he should have intended. Accuracy as used here, in other words, is synonymous with Scatter. 当螺栓拧紧时，给定工具或程序在螺栓中产生预紧力的精度度量。例如，一个普通的扭矩扳手据说可以产生精度为+30%的预载。然而，平均预载可能不是设计者预期的。这里使用的准确度是分散度的同义词。 |
| 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。 |
| Turning | 车削 |
Turning is a machining process for generating external surfaces of revolution by the action of a cutting tool on a rotating workpiece, usually in a lathe. The rotation of a workpiece held against a cutting tool in a lathe to produce components with a circular cross section. 车削是一种机械加工过程，通常在车床上，通过刀具对旋转工件的作用产生旋转外表面。在车床中，工件靠着刀具旋转，以生产具有圆形横截面的部件。 |
| Embrittlement | 脆化 |
The loss of ductility or fracture toughness of materials, either during processing or in service. The severe loss of ductility or toughness or both, of a material, usually a metal or alloy. Many forms of embrittlement can lead to brittle fracture. Many forms can occur during thermal treatment or elevated-temperature service (thermally induced embrittlement). Some of these forms of embrittlement, which affect steels, include blue brittleness, 885 °F (475 °C) embrittlement, quench-age embrittlement, sigma-phase embrittlement, strain-age embrittlement, temper embrittlement, tempered martensite embrittlement, and thermal embrittlement. In addition, steels and other metals and alloys can be embrittled by environmental conditions (environmentally assisted embrittlement). The forms of environmental embrittlement include acid embrittlement, caustic embrittlement, corrosion embrittlement, creep-rupture embrittlement, hydrogen embrittlement, liquid metal embrittlement, neutron embrittlement, solder embrittlement, solid metal embrittlement, and stress-corrosion cracking. 材料在加工或使用过程中的延展性或断裂韧性损失。通常是金属或合金的延展性或韧性或两者的严重损失。多种形式的脆化可导致脆性断裂。在热处理或高温服务期间，可能会出现多种形式（热致脆化）。影响钢的一些脆化形式包括蓝脆、885°F（475°C）脆化、淬火时效脆化、西格玛相脆化、应变时效脆化，回火脆化、回火马氏体脆化和热脆化。此外，钢和其他金属和合金可能因环境条件而脆化（环境辅助脆化）。环境脆化的形式包括酸脆化、碱脆化、腐蚀脆化、蠕变断裂脆化、氢脆化、液态金属脆化、中子脆化、焊料脆化、固态金属脆化和应力腐蚀开裂。 |
| 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。 |
| Clearance hole | 间隙孔 |
A hole of specified size such that a bolt, stud, etc. of the same nominal size will always pass through. 指定尺寸的孔，使相同标称尺寸的螺栓、螺柱等可以通过。 |
| Gasket stress | 垫片应力 |
The contact stress exerted on the gasket by the joint members. 连接件施加在垫片上的接触应力。 |
| Sample standard deviation (s) | 样本标准偏差（s） |
The square root of the sample variance. It is a point estimate of the population standard deviation, a measure of the “spread”of the frequency distribution of a population. This value of sprovides a statistic that is used in computing interval estimates and several test statistics. For small sample sizes, s underestimates the population standard deviation. 样本方差的平方根。它是总体标准偏差的点估计，是总体频率分布“扩散”的度量。SPR的这个值提供了一个用于计算区间估计和若干测试统计量的统计量。对于小样本，s低估了总体标准偏差。 |
| 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。 |
| Hardenability | 淬透性 |
Defined as the ability of a ferrous material to acquire hardness after austenitization and quenching. The relative ability of a ferrous alloy to form martensite when quenched from a temperature above the upper critical temperature. Hardenability is commonly measured as the distance below a quenched surface where the metal exhibits a specific hardness (50 HRC, for example) or a specific percentage of martensite in the microstructure. 定义为黑色金属材料在奥氏体化和淬火后获得硬度的能力。铁合金从高于上临界温度的温度淬火时形成马氏体的相对能力。淬透性通常以淬火表面下方的距离来测量，金属在淬火表面处表现出特定硬度（例如50HRC）或微观结构中马氏体的特定百分比。 |
| Minimum material condition | 最小材料条件 |
(minimum metal condition) The situation where the volume of a manufactured component corresponds to the lower limit of all toleranced external dimensions and to the upper limit for all internal dimensions. （最小金属条件）制造部件的体积对应于所有公差外部尺寸的下限和所有内部尺寸的上限的情况。 |
| Bypass flow meter | 旁通流量计 |
(shunt flow meter) A flow meter installed in a pipework bypass which may itself be part of the flow meter. An orifice plate is used to ensure a fraction of the main flow passes through the bypass. （分流流量计）安装在管道旁路中的流量计，它本身可能是流量计的一部分。孔板用于确保一部分主流通过旁路。 |
| Complete decarburization | 完全脱碳 |
Decarburization with sufficient carbon loss to show only clearly defined ferrite grains under metallographic examination. 脱碳，具有足够的碳损失，以在金相检查下仅显示清晰定义的铁素体晶粒。 |
| Sigma phase | σ相 |
A hard, brittle, nonmagnetic intermediate phase with a tetragonal crystal structure, containing 30 atoms per unit cell, space group P42/mnm, occurring in many binary and ternary alloys of the transition elements. The composition of this phase in the various systems is not the same, and the phase usually exhibits a wide range in homogeneity. Alloying with a third transition element usually enlarges the field of homogeneity and extends it deep into the ternary section. 一种硬、脆、非磁性中间相，具有四方晶体结构，每单位晶胞含有30个原子，空间群P42/mnm，存在于许多过渡元素的二元和三元合金中。该相在各种系统中的组成不尽相同，并且该相通常表现出宽范围的均匀性。与第三过渡元素的合金化通常会扩大均匀性范围，并将其延伸到三元区。 |
| Hypoeutectic alloy | 亚共晶合金 |
In an alloy system exhibiting a eutectic, any alloy whose composition has an excess of base metal compared with the eutectic composition, and whose equilibrium microstructure contains some eutectic structure. 在呈现共晶的合金系统中，其成分比共晶成分多的任何合金，其平衡微观结构包含一些共晶结构。 |
| Compressive stress | 压缩应力 |
A stress that causes an elastic body to deform (shorten) in the direction of the applied load. Contrast with tensile stress. 使弹性体沿施加载荷方向变形（缩短）的应力。与拉应力对比。 |
| 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）。 |
| 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。 |
| Velocity defect (Unit m/s) | 速度亏损（单位：m/s） |
In a viscous flow, such as a boundary layer or wake, the reduction in velocity, due to friction, compared with that of the free stream. 在粘性流中，如边界层或尾迹，由于摩擦，与自由流相比，速度降低。 |
| Clevis | U形夹 |
A U-shaped hook with holes at the ends through which a retaining bolt or pin (clevis pin) passes. 一种U形钩，末端有孔，固定螺栓或销（U形销）穿过这些孔。 |
| 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。 |
| Elastic resilience | 弹性回弹 |
The amount of energy absorbed in stressing a material up to the elastic limit; or, the amount of energy that can be recovered when stress is released from the elastic limit. 向材料施加应力直至弹性极限所吸收的能量；或者当应力从弹性极限释放时可以恢复的能量值。 |
| Coefficient of restitution (e) | 回弹系数（e） |
The ratio of the relative velocity of two colliding bodies after collision to that before. In perfectly elastic collisions e = 1; when all the impact energy is dissipated, e = 0. 两个碰撞体在碰撞后与碰撞前的相对速度之比。在完全弹性碰撞中e=1；当所有的冲击能量都消散时，e=0。 |
| Combined carbon | 复合碳 |
The part of the total carbon in steel or cast iron that is present as other than free carbon. 钢或铸铁中总碳中除游离碳外的部分。 |
| 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。 |
| Bolt | 螺栓 |
(machine bolt) A fastener in the form of an externally-threaded cylinder with a head on one end that is inserted through holes in assembled parts that are then held together by a nut tightened on to the thread. A bolt has an unthreaded region below the head so that when located in a hole, transverse loads are borne by two plain cylindrical surfaces in contact. In contrast, use of a machine screw, that has threads all along its length, results in threads bearing against the plain surface of a hole. Officially, a threaded fastener designed to be used with a nut. （机械螺栓）外螺纹圆柱状紧固件：一端有头的紧固件，通过装配零件上的孔插入，然后通过拧紧到螺纹上的螺母固定在一起。螺栓头部下方有一个无螺纹区域，因此当位于孔中时，横向载荷由两个接触的平面圆柱面承担。相反，使用沿其长度具有螺纹的机器螺钉，会导致螺纹支撑在孔的平面上。正式情况下，螺纹紧固件设计用于与螺母一起使用。 |
| 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。 |
| Subcritical annealing | 不完全退火 |
A process anneal performed on ferrous alloys at a temperature below Ac1. 在低于Ac1的温度下对铁合金进行的工艺退火。 |
| Gear motor | 齿轮马达 |
Essentially a gear pump run in reverse, in which high-pressure fluid supplied to one side of the casing causes the gears to rotate. 本质上是一个齿轮泵反向运行，其中供应到外壳一侧的高压流体导致齿轮旋转。 |
| Brittle | 脆性材料 |
A brittle material is one that breaks, often suddenly, with no permanent deformation. Examples of brittle materials are some cast irons, glass, concrete, and some plastics. A bolt is said to be brittle if it will break when stretched only a small amount past its yield point. 脆性材料通常会突然断裂，不会产生永久变形。脆性材料的例子有一些铸铁、玻璃、混凝土和一些塑料。如果螺栓在拉伸时仅超过其屈服点一小部分就会断裂，则称其为脆性螺栓。 |
| 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。 |
| Stress relaxation | 应力松弛 |
The slow decrease in stress level within a part (e.g., a bolt) which is heavily loaded under constant deflection conditions. A ‘‘cousin’’ to creep, which is a slow change in geometry under constant stress conditions. The time-dependent decrease in stress in a solid under constant strain at constant temperature due to creep. The stress-relaxation behavior of a metal is usually shown in a stress-relaxation curve. 在恒定挠曲条件下，零件（如螺栓）内的应力水平缓慢降低，该零件承受重荷载。蠕变的“表亲”，是在恒定应力条件下几何结构的缓慢变化。在恒定温度下，由于蠕变，固体在恒定应变下的应力随时间变化的减小。金属的应力松弛行为通常显示在应力松弛曲线中。 |
| Ferrite | 铁素体 |
A solid solution of one or more elements in body-centered cubic iron. Unless otherwise designated (for instance, as chromium ferrite), the solute is generally assumed to be carbon. On some equilibrium diagrams, there are two ferrite regions separated by an austenite area. The lower area is alpha ferrite; the upper, delta ferrite. If there is no designation, alpha ferrite is assumed. 一种或多种元素在体心立方铁中的固溶体。除非另有说明（例如，铁酸铬），否则通常假定溶质为碳。在一些平衡图上，有两个铁素体区域被一个奥氏体区域隔开。下部区域为α铁素体；上部，δ铁氧体。如果没有指定，则假定为 α 铁氧体。 |
| Calorizing | 热化 |
Imparting resistance to oxidation to an iron or steel surface by heating in aluminum powder at 800 to 1000 °C (1470 to 1830 °F). 通过在800至1000°C（1470至1830°F）下加热铝粉，赋予铁或钢表面抗氧化性。 |
| Gravity | 重力 |
The attractive force by which bodies are drawn towards the centre of Earth or other celestial object. Its intensity is measured by the acceleration produced. The gravitational force of attraction at the surface of a planet or other celestial body. The Earth’s gravity produces an acceleration of around 9.8m/s² for any unsupported body. 物体被拉向地球中心或其他天体的吸引力，行星或其他天体表面的引力。它的强度是通过产生的加速度来衡量的，对于任何无支撑的物体，地球的重力都会产生大约9.8m/s²的加速度。 |
| Turret lathe | 六角车床 |
A capstan lathe in which the capstan is driven mechanically or hydraulically to provide assigned tool paths to perform a specified sequence of operations in the repetitive production of parts. 一种绞盘车床，其中绞盘由机械或液压驱动，以提供指定的刀具路径，在零件的重复生产中执行指定的操作顺序。 |
| Computed path control | 计算路径控制 |
In CNC or robotics, the use of a control program to determine the required path for the tool or end effector. This required path forms the set points for the motor controllers moving the machine tool or robot. 在CNC或机器人技术中，使用控制程序来确定工具或末端执行器所需的路径。这条所需的路径形成了用于移动机床或机器人的电机控制器的设定点。 |
| Radial flow | 径向流 |
radial flow Fluid flow for which the principal direction of flow is either radially inward or radially outward relative to an axial direction. 径向流动流体流动的主要方向是径向向内或径向向外流动。 |
| Radial load (Unit N) | 径向负荷（单位：N） |
1. Centrifugal loading induced in a rotating body. 2. (through-wallthickness load) The radial component of loading arising from internal or external pressurization of a closed vessel. There will also be axial and hoop loading. 1.旋转体中产生的离心载荷。2.（贯穿壁厚载荷）由封闭容器的内部或外部加压产生的载荷的径向分量。还存在轴向和环向载荷。 |
| Barrier protection | 屏障保护 |
The coating on a fastener is said to provide barrier protection if it merely isolates the fastener from the environment. Paint, for example, provides barrier protection. 如果仅将紧固件与环境隔离，则据说紧固件上的涂层可提供屏障保护。例如，油漆提供屏障保护。 |
| Unison ring | 协调环 |
In a turbomachine with adjustable guide or stator vanes, the ring to which a set of vanes is linked such that when the ring is rotated, all vane angles are adjusted. 在具有可调导向叶片或定子叶片的涡轮机中，一组叶片连接到的环，当环旋转时，所有叶片角度都可调整。 |
| Maximum allowable operating pressure (Unit Pa) | 最大允许使用压力（单位Pa） |
The highest pressure at which any pressure system may be operated, usually 10 to 20% below the maximum allowable working pressure. 任何压力系统可运行的最高压力，通常比最大允许工作压力低10%至20%。 |
| 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。 |
| Concentrated load | 集中负荷 |
A load on a component which is distributed over a very small area, idealized as the line load of a wedge or knife edge, and the point load of a cone. 分布在非常小的区域上的部件上的载荷，理想化为楔形或刀刃的线载荷和锥体的点载荷。 |
| Radiation pressure (Unit μPa) | 辐射压力（单位：μPa） |
The pressure exerted on a surface exposed to any form of electromagnetic radiation. If the radiation is absorbed, it is equal to the power-flux density divided by the speed of light. 施加在暴露于任何形式电磁辐射的表面上的压力。如果辐射被吸收，它等于功率通量密度除以光速。 |
| 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。 |
| Universal joint (Hooke’s joint) | 万向节（胡克接头） |
A double-pivoted connection that allows power and torque to be transmitted between two shafts at an angle to each other. For constant driving angular velocity of the input yoke, the angular velocity of the output yoke fluctuates by amounts depending on the angle of intersection of the shafts. Speeds of the driving and driven shafts may be made identical (giving a constant-velocity joint) when an intermediate shaft, at each end of which there is a universal joint, is interposed. The driving and driven shafts must be equally inclined to the intermediate shaft, the two forks of which must lie in the same plane. 一种双枢轴连接，允许动力和扭矩以一定角度在两个轴之间传递。对于输入磁轭的恒定驱动角速度，输出磁轭的角速度根据轴的相交角度波动。当插入中间轴时，驱动轴和从动轴的速度可以相同（提供恒定速度接头），中间轴的两端都有万向节。主动轴和从动轴必须与中间轴倾斜相等，中间轴的两个叉必须位于同一平面内。 |
| Taper key | 楔键 |
A key with parallel sides but tapering cross section along its length. 边平行但横截面沿其长度逐渐变细的键。 |
| Tensile strength (Unit Pa) | 抗拉强度（单位Pa） |
In tension testing, the ratio of maximum load to original cross-sectional area. Also known as ultimate strength. The resistance that a material offers to tensile stress. It is defined as the smallest tensile stress required to break the body. (ultimate strength, ultimate tensile strength, UTS, Rm, Rm) The nominal or engineering stress given by the maximum load in a tension test divided by the original cross-sectional area of the specimen. The maximum load could be the fracture load for a brittle material, but for a ductile material it is usually taken as the load at which necking begins, beyond which the load falls. 在拉伸试验中，最大载荷与原始横截面积之比。也称为极限强度。材料对拉伸应力的抵抗力。它被定义为破坏主体所需的最小拉伸应力。（极限强度、极限抗拉强度、UTS、Rm、Rm）拉伸试验中最大载荷除以试样原始横截面积得出的标称或工程应力。对于脆性材料，最大载荷可以是断裂载荷，但对于韧性材料，最大荷载通常被视为颈缩开始时的载荷，超过该载荷时，载荷下降。 |
| 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。 |
| Abelian group | 阿贝尔群 |
Property of a group of elements associated with a binary operation. In an Abelian group, the group elements commute under the binary operation. If a and b are any two group elements and if the (+) sign denotes the binary operation, then, for an Abelian group, 与二元运算相关的一组元素的属性。在阿贝尔群中，群元素在二元运算下交换。如果a和b是任意两个群元素并且（+）符号表示二元运算 |
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