| 词或词组 | 中文 | 英文解释中文解释 |
|---|---|---|
| Terminal temperature difference (Unit K) | 终端温差（单位K） |
The temperature difference between the two fluid streams at either inlet or outlet of a heat exchanger. 热交换器入口或出口处两种流体流之间的温差。 |
| Carburizing | 渗碳 |
Absorption and diffusion of carbon into solid ferrous alloys by heating, to a temperature usually above Ac3, in contact with a suitable carbonaceous material. A form of case hardening that produces a carbon gradient extending inward from the surface, enabling the surface layer to be hardened either by quenching directly from the carburizing temperature or by cooling to room temperature, then reaustenitizing and quenching. 通过与合适的含碳材料接触加热至通常高于Ac3的温度，将碳吸收和扩散到固体铁合金中。一种表面硬化形式，产生从表面向内延伸的碳梯度，通过直接从渗碳温度淬火或冷却至室温，然后重新奥氏体化和淬火，使表层硬化。 |
| Resistance thermometer | 电阻温度计 |
A thermometer in which the sensing element is basically a metal wire, usually of platinum, for which the variation of resistance with temperature is known accurately. A resistance pyrometer is a resistance thermometer intended for use up to about 1 000°C. 一种温度计，其中传感元件基本上是一根金属线，通常是铂，可以准确地知道电阻随温度的变化。电阻高温计是一种电阻温度计，用于高达约1000°C的温度。 |
| Prying | 撬动 |
The magnification of an External load by a pseudolever action when that load is an Eccentric tensile load. 当外部荷载为偏心拉伸荷载时，通过伪杠杆作用放大外部荷载。 |
| Nut factor | 螺母系数 |
An experimental constant used to evaluate or describe the ratio between the torque applied to a fastener and the Preload achieved as a result. 用于评估或描述施加在紧固件上的扭矩与由此获得的预载之间的比率的实验常数。 |
| Circular pitch | 齿距 |
The distance from the center of one gear tooth to the center of the next gear tooth measured on the pitch line. 在节线上测量的从一个轮齿中心到下一个轮齿中心的距离。 |
| 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。 |
| Centre line | 中心线 |
1. In an engineering drawing, a line of symmetry. 2. An imaginary line along a pipe, duct, or shaft that defines an axis of symmetry. 3. An imaginary straight line parallel to the intended direction of a surface located such that the areas above and below the line and the real wavy (rough) surface cancel out. 1.在工程图中，对称线。2.沿着管道、管道或竖井定义对称轴的假想线。3.一条平行于表面预期方向的假想直线，该直线上方和下方的区域与真实的波状（粗糙）表面相抵消。 |
| Spring | 弹簧 |
An elastic component which stores mechanical energy and exerts a force when deformed. The slope of the curve of applied force F to the deflexion of a spring x, dF/dx, is termed the spring rate or spring modulus k with unit N/m. For a linear spring, the F(x) curve is proportional and k is called the spring constant. An elastic device which yields under stress or pressure but returns to its original state or position when the stress or pressure is removed. 储存机械能并在变形时施加力的弹性部件。作用力F与弹簧x偏转的曲线斜率dF/dx称为弹簧率或弹簧模量k，单位为N/m。对于线性弹簧，F（x）曲线成比例，k称为弹簧常数。一种弹性装置，在应力或压力下屈服，但在应力和压力消除后恢复到其原始状态或位置。 |
| Permanent set | 永久变形 |
The deformation or strain remaining in a previously stressed body after release of load. 释放荷载后，先前受力物体中剩余的变形或应变。 |
| Ductile cast iron | 球墨铸铁 |
A cast iron that has been treated while molten with an element such as magnesium or cerium to induce the formation of free graphite as nodules or spherulites, which imparts a measurable degree of ductility to the cast metal. Also known as nodular cast iron, spherulitic graphite cast iron and SG iron. 一种铸铁，在熔融时用镁或铈等元素进行处理，以诱导游离石墨形成为球粒或球晶，从而赋予铸造金属可测量的延展性。又称球墨铸铁、球晶石墨铸铁和SG铸铁。 |
| Wind pump | 风泵 |
A pump driven directly by a windmill on a tower. Widely used in remote locations. 由塔上的风车直接驱动的泵。广泛应用于偏远地区。 |
| Shear joint | 剪切接头 |
A joint which is subjected primarily to loads acting more or less perpendicular to the axes of the bolts. 主要承受或多或少垂直于螺栓轴线的载荷的接头。 |
| Lock nut | 锁紧螺母 |
A type of nut that is prevented from loosening under vibration. The locking action is accomplished by squeezing, gripping or jamming against the bolt threads. A nut which provides extra resistance to vibration loosening (beyond that produced by proper Preload ), either by providing some form of Prevailing torque, or, in free-spinning lock nuts, by deforming, cramping, or biting into mating parts when fully tightened. 1. A thin auxiliary nut tightened against another nut to prevent loosening. 2. A single nut with special features that prevent loosening. 一种在振动下防止松动的螺母。锁定动作通过挤压、夹紧或卡住螺栓螺纹来完成。通过提供某种形式的主要扭矩，或在自由旋转锁紧螺母中，通过完全拧紧时变形、夹紧或咬入配合零件，提供额外的抗振动松动能力（超出适当预载产生的能力）。1.一个薄的辅助螺母，拧紧到另一个螺母上以防止松动。2.具有防止松动的特殊功能的单个螺母。 |
| Constant-mesh gearbox | 恒啮合齿轮箱 |
A gearbox in which the pairs of gears giving different speed ratios are constantly in mesh, different ratios being obtained by connecting or disconnecting the relevant gear to the driving shaft. 一种齿轮箱，其中提供不同速比的齿轮对始终啮合，通过将相关齿轮连接或断开驱动轴获得不同的速比。 |
| Proof strength (Unit Pa) | 验证强度（单位Pa） |
(proof stress, Rp, Rp,) The yield strength (offset yield strength) at some fixed value of the permanent strain given by the intersection of a line offset from, but parallel to, the elastic loading line and the engineering stress-engineering strain curve. The offset is arbitrary but is usually 0.1, 0.2, or 0.5% permanent strain (the proof strain). Used for materials which do not exhibit a sharply defined yield point. The notation Rp0.2 or Rp0.2 is employed for the 0.2% proof stress. （验证应力，Rp）在永久应变的某个固定值下的屈服强度（偏移屈服强度），由偏离但平行于弹性加载线的线与工程应力-工程应变曲线的交点给出。偏移是任意的，但通常为0.1、0.2或0.5%的永久应变（验证应变）。用于没有明确定义屈服点的材料。对于0.2%的验证应力，采用符号Rp0.2。 |
| Mechanical alloying | 机械合金化 |
Production of alloys from powders by consolidation, e.g. hotpressing or extrusion, followed by hot and/or cold working and final annealing. Materials such as dispersion-strengthened alloys, high-temperature aluminium alloys, and amorphous alloys can be made in this way. 通过固结（例如热压或挤压）从粉末生产合金，然后进行热和/或冷加工和最终退火。用这种方法可以制造弥散强化合金、高温铝合金和非晶合金等材料。 |
| Waist | 腰部 |
The joint in a robot corresponding to the human waist, i.e. providing rotation about a vertical axis. In an articulated robot, the first joint mounted at the base frame. 机器人中的关节对应于人的腰部，即提供绕垂直轴的旋转。在关节式机器人中，第一个关节安装在基架上。 |
| Corrosion fatigue | 腐蚀疲劳 |
Cracking produced by the combined action of repeated or fluctuating stress and a corrosive environment at lower stress levels or fewer cycles than would be required in the absence of a corrosive environment. 由重复或波动的应力和腐蚀环境的联合作用产生的开裂，其应力水平低于没有腐蚀环境时所需的应力水平或循环次数更少。 |
| Track rod | 横拉杆 |
A bar connecting the ends of the steering arms in an automotive vehicle. 连接汽车转向臂端部的杆。 |
| Crack-growth rate | 裂纹增长速度 |
Rate of propagation of a crack through a material due to statically or dynamically applied load. 由于静态或动态施加的载荷，裂纹在材料中的扩展速率。 |
| Selective heating | 局部加热 |
Intentionally heating only certain portions of a workpiece. 有意仅加热工件的某些部分。 |
| Valve | 阀门 |
Any of various manual or automatic devices that are able to initiate, regulate, or stop the flow of a fluid through a conduit or from a closed container. 任何一种手动或自动装置，能够启动、调节或停止通过导管或封闭容器的流体流动。 |
| 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。 |
| Remaining stress | 残留应力 |
The stress remaining at a given time during a stress-relaxation test. See also stress relaxation. 在应力松弛试验期间在给定时间内剩余的应力。参见压力松弛。 |
| Critical temperature | 临界温度 |
(1) Synonymous with critical point if the pressure is constant. (2) The temperature above which the vapor phase cannot be condensed to liquid by an increase in pressure. （1） 如果压力恒定，则与临界点同义。（2） 高于该温度时，气相不能通过压力升高而冷凝为液体。 |
| Yielding | 屈服 |
Evidence of plastic deformation in structural materials. Also known as plastic flow or creep. 结构材料塑性变形的证据。也称为塑性流动或蠕变。 |
| Vacuum carburizing | 真空渗碳 |
A high-temperature gas carburizing process using furnace pressures between 7 and 55 kPa during the carburizing portion of the cycle. 在循环的渗碳部分期间使用7至55kPa之间的炉压的高温气体渗碳工艺。 |
| Scatter | 分散 |
Data points or calculations are said to be scattered when they are not all the same. A ‘‘lot of scatter in preload’’ means wide variation in the preloads found in individual bolts. 当数据点或计算不尽相同时，它们被称为分散的。“预载的大量分散”意味着单个螺栓中的预载差异很大。 |
| Double-shear test | 双剪试验 |
A shear test having two stationary, shear blades and one moving one and that uses solid round bars as test specimens. 一种剪切试验，具有两个固定的剪切刀片和一个移动的刀片，并使用实心圆棒作为试样。 |
| 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。 |
| Face | 表平面 |
To machine a flat surface perpendicular to the axis at rotation on a lathe. 在车床上加工一个垂直于旋转轴的平面。 |
| Quench-age embrittlement | 淬火时效脆化 |
Embrittlement of low-carbon steels resulting from precipitation of solute carbon at existing dislocations and from precipitation hardening of the steel caused by differences in ferrite at different temperatures. Quenchage embrittlement usually is caused by rapid cooling of the steel from temperatures slightly below Ac1 (the temperature at which austenite begins to form), and can be minimized by quenching from lower temperatures. 低碳钢的脆化是由于溶质碳在现有位错处的沉淀和铁素体在不同温度下的差异导致的钢沉淀硬化造成的。淬火脆性通常是由钢从略低于Ac1的温度（奥氏体开始形成的温度）快速冷却引起的，可以通过从较低温度淬火来最小化。 |
| Terminal velocity (Unit m/s) | 终端速度（单位：m/s） |
The velocity reached by an object in free fall through a fluid when the upward drag and buoyancy forces just balance the object’s weight. For an object with a density lower than that of the fluid, the terminal velocity is vertically upwards. 当向上的阻力和浮力正好平衡物体的重量时，物体自由下落通过流体达到的速度。对于密度低于流体密度的物体，终端速度垂直向上。 |
| Tap | 旋塞 |
1. A threaded hard metal plug for cutting screw threads in holes. It has longitudinal grooves for the clearance of chips while cutting. Progressive cutting is achieved by using three taps in succession: taper, second, and plug. First and second taps have tapers to help start the thread along the axis of the hole; the plug tap has no taper and is used on the final cut in a blind hole. 2. A valve in, or at the end of, a pipeline. 1.一种用于在孔中切割螺纹的螺纹硬金属塞。它具有纵向凹槽，用于在切割时清除切屑。渐进式切割通过连续使用三个丝锥实现：锥度、二次和塞。第一和第二丝锥具有锥度，以帮助沿孔的轴线开始螺纹；塞式丝锥没有锥度，用于盲孔的最终切割。2.管道中或管道末端的阀门。 |
| Fahrenheit | 华氏度 |
The temperature scale based on the freezing point of water (32ºF) and the boiling point of water (212ºF). The interval between these points is divided into 180 equal parts. Although replaced by the Celsius scale, the Fahrenheit scale is still sometimes used for non-scientific measurements. 温标基于水的冰点（32ºF）和水的沸点（212ºF）。这些点之间的间隔被分成180等份。尽管被摄氏刻度所取代，华氏刻度有时仍用于非科学测量。 |
| Eyebolt (eyescrew) | 吊环螺栓（眼螺丝） |
A bolt threaded at one end and bent to a loop at the other end. A bolt or screw with a closed loop in place of a head. 一端有螺纹，另一端弯曲成环的螺栓。带有闭合环代替头部的螺栓或螺钉。 |
| Weld penetration | 焊接熔深 |
It is the depth below the surfaces, as revealed in microstructural sections of joined metals, which is melted during welding. 它是焊接过程中熔化的连接金属的微观结构截面所显示的表面以下的深度。 |
| Tear strength (Unit N/m) | 撕裂强度（单位：N/m） |
The tensile force divided by the sheet thickness required to tear a pre-split sheet material at a specified rate. Particularly used for plastics, rubber, fabrics, and elastomers. Since the units are not those of stress but equivalent to J/m², the units of toughness, the term ‘strength’ is strictly incorrect. 按规定速率撕裂预裂片材所需的张力除以片材厚度。特别用于塑料、橡胶、织物和弹性体。由于单位不是应力单位，而是相当于J/m²，韧性单位，“强度”一词是完全错误的。 |
| Latent heat | 潜热 |
Thermal energy absorbed or released when a substance undergoes a phase change. 物质发生相变时吸收或释放的热能。 |
| Force ratio | 力比 |
The factor by which a simple machine multiplies an applied force. It is the ratio of the load (output force) to the effort (input force). 简单机器乘以所施加的力的因子。它是负载（输出力）与作用力（输入力）的比值。 |
| 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。 |
| Bulk velocity | 体积速度 |
(average velocity, V) (Unit m/s) For fluid flow in a pipe or duct, the average flow velocity, given by V = ṁ/ρA where ṁ is the mass flow rate, ρ is the fluid density, and A is the duct cross-sectional area. （平均速度，V）（单位m/s）对于管道或管道中的流体流动，平均流速，由V=ṁ/ρA给出，其中ṁ是质量流量，ρ是流体密度，A是管道截面积。 |
| Toughening mechanisms | 增韧机理 |
Various methods of increasing the resistance to crack initiation and propagation in materials. They include transformation toughening, in which the microstructure around the crack tip alters so as to slow down or arrest cracks; deflexion of cracks; various ways of de-sharpening crack tips; fibre bridging of cracks; and fibre pull-out. 增加材料中裂纹萌生和扩展阻力的各种方法。它们包括相变增韧，其中裂纹尖端周围的微观结构发生变化，以减缓或阻止裂纹；裂纹偏转；消除裂纹尖端锐化的各种方法；纤维桥接裂纹；和纤维拉出。 |
| Regenerative pump | 涡流泵 |
(regenerative turbine pump, peripheral pump) A pump with a double-sided impeller having a large number of radial blades. The pressure of the pumped liquid increases progressively over several revolutions of the impeller. It is particularly suited to producing large heads at small flow rates without cavitation. （再生涡轮泵，外围泵）具有具有大量径向叶片的双面叶轮的泵。泵送液体的压力在叶轮的几圈内逐渐增加。它特别适合于在小流速下产生大水头且不产生气穴。 |
| 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。 |
| Turbine flow meter | 涡轮流量计 |
(axial flow meter, propeller meter) An in-line flow meter in which the rotation speed N of a propeller or rotor is a measure of the mass flowrate ṁ. Calibration is always necessary but with appropriate design ṁ is closely proportional to N over a wide range. （轴向流量计、螺旋桨流量计）一种串联流量计，其中螺旋桨或转子的转速N是质量流量的测量值ṁ. 校准总是必要的，但需要适当的设计ṁ在很宽的范围内与N成正比。 |
| Retaining clip | 固定夹 |
(R-clip, hair cotter pin) A wire clip roughly with the shape of the letter R. The straight part of the clip passes through a hole drilled into a shaft or rod such that a wheel is held in position on the shaft, or the shaft is prevented from moving axially. （R形夹，开口销）大致与字母R形状相同的线夹。线夹的直线部分穿过钻在轴或杆上的孔，从而将车轮固定在轴上，或防止轴轴向移动。 |
| 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。 |
| Atomization | 雾化 |
The production of a spray of fine droplets from a liquid, such as diesel oil or petrol, by injection through a nozzle (an atomizer). 通过喷嘴（雾化器）喷射从液体（例如柴油或汽油）中产生细小液滴喷雾。 |
| 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。 |
| Nominal size | 公称尺寸 |
The intended size of a component. The actual size will depend on manufacturing tolerances. 组件的预期尺寸。实际尺寸取决于制造公差。 |
| Critical diameter | 临界直径 |
(D) Diameter of the bar that can be fully hardened with 50% martensite at its center. （D）中心有50%马氏体可完全硬化的棒材直径。 |
| Anneal to temper | 退火回火 |
A final partial anneal that softens a cold worked nonferrous alloy to a specified level of hardness or tensile strength. 将冷加工的有色金属合金软化到规定的硬度或抗拉强度水平的最终局部退火。 |
| Absolute temperature (Unit K) | 绝对温度（单位K） |
A temperature T measured relative to absolute zero, 0 K or −273.15°C, the lowest temperature achievable at which molecular motion vanishes so that a body would have zero heat energy. The kelvin is equal in magnitude to the degree Celsius (°C). The kelvin temperature scale (kelvin absolute temperature scale) is an absolute or thermodynamic temperature scale derived from the Celsius scale: T(K) = T(°C) + 273.15. The Rankine absolute scale is derived from the Fahrenheit scale such that T(R) = T(°F) + 459.67, i.e. a scale relative to 0 R or −459.67°F where R is the Rankine degree symbol and °F is the Fahrenheit symbol. 相对于绝对零、0K或0K测量的温度T−273.15°C，分子运动消失的最低温度，因此物体的热能为零。开尔文的大小等于摄氏度（℃）。开尔文温度标度（开尔文绝对温度标度）是从摄氏标度得出的绝对或热力学温度标度：T（K）=T（°C）+273.15。兰金绝对标度是从华氏标度得出，使得T（R）=T（°F）+459.67，即相对于0R或0R的标度−459.67°F，其中R是朗肯度符号，°F是华氏度符号。 |
| Punch | 冲床 |
1. A hand tool with a sharp point, used to mark the position of a hole centre in a workpiece prior to drilling. 2. A flat-ended tool with sharp edges, used to shear out a hole in a plate that is supported underneath on a die having a slightly larger same-shaped orifice. 1.一种带有尖头的手动工具，用于在钻孔前标记工件中孔中心的位置。2.一种具有锐边的平头工具，用于剪切板上的孔，该板支撑在具有稍大相同形状孔口的模具下方。 |
| Normalizing | 正火 |
Heating a ferrous alloy to a suitable temperature above the transformation range and then cooling in air to a temperature substantially below the transformation range. 将铁合金加热至高于转变范围的合适温度，然后在空气中冷却至基本低于转变范围的温度。 |
| 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）。 |
| Chain dimensioning | 链条尺寸标注 |
On an engineering drawing, where the end point of one dimension is the starting point for the next. Parallel dimensioning is preferred as chain dimensioning can lead to the accumulation of tolerances. 在工程图纸上，其中一个尺寸的终点是下一个的起点。平行尺寸标注是首选，因为链尺寸标注可能导致公差累积。 |
| 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。 |
| Mechanical vibration | 机械振动 |
The motion of a particle or body which oscillates about a position of equilibrium. 围绕平衡位置摆动的粒子或物体的运动。 |
| 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。 |
| Ideal crack | 理想裂缝 |
A simplified model of a crack used in elastic-stress analysis. In a stress-free body, the crack has two smooth surfaces that are coincident and join within the body along a smooth curve called the crack front; in two-dimensional representations, the crack front is called the crack tip. 用于弹性应力分析的裂纹简化模型。在无应力物体中，裂纹有两个光滑表面，它们在物体内沿称为裂纹前缘的平滑曲线重合并连接；在二维表示中，裂纹前缘称为裂纹尖端。 |
| 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。 |
| Multiple threaded screw | 多螺纹螺钉 |
A screw with two or more threads cut around the periphery of the workpiece to provide an increased lead with a specified pitch. 一种螺钉，具有围绕工件周边切割的两个或多个螺纹，以提供具有指定螺距的增加的导程。 |
| Lead screw | 丝杠 |
The master screw running along the length of the bed of a lathe from which all screws threads on that machine are cut. Master screw used for cutting a screw thread in a lathe. 沿车床床身长度方向运行的主螺钉，该机床上的所有螺钉和螺纹都从主螺钉上切割下来。用于在车床上切削螺纹的主螺钉。 |
| Fastener standard | 紧固件标准 |
A document which details the attributes of a finished fastener and includes such characteristics as geometry, material or chemistry, heat treatment, finish, testing lot size, and packaging. 详细说明紧固件属性的文件，包括几何形状、材料或化学、热处理、表面处理、测试批量和包装等特性。 |
| Pressure control valve | 压力控制阀 |
A valve used to set the pressure level in a pressure vessel or piping system. 用于设置压力容器或管道系统中压力水平的阀门。 |
| Standard | 标准 |
(standard specification) A set of specifications for components, machines, materials, or processes intended to achieve uniformity, efficiency, and a specified quality. In the UK, standards issued by the British Standards Institution (BSI) are now generally those of the International Organization for Standardization (ISO). （标准规范）为实现一致性、效率和特定质量而制定的一套组件、机器、材料或工艺规范。在英国，英国标准协会（BSI）发布的标准现在基本上是国际标准化组织（ISO）的标准。 |
| Bypass ratio | 旁路比 |
In a turbofan engine, the ratio of the mass flow rate of the bypass stream to the mass flow rate through the core of the engine. 在涡扇发动机中，旁通流的质量流量与通过发动机核心的质量流量之比。 |
| Vapour-pressure thermometer | 蒸汽压力温度计 |
(vapour-filled thermometer) A type of fluidexpansion thermometer in which the working fluid is a volatile liquid. （蒸汽填充温度计）一种流体膨胀温度计，其中工作流体为挥发性液体。 |
| Full annealing | 全退火 |
An imprecise term that denotes an annealing cycle to produce minimum strength and hardness. For the term to be meaningful, the composition and starting condition of the material and the time-temperature cycle used must be stated. Annealing a ferrous alloy by austenitizing and then cooling slowly through the transformation range. 一个不精确的术语，表示产生最小强度和硬度的退火循环。为了使该术语有意义，必须说明材料的组成和起始条件以及使用的时间-温度循环。通过奥氏体化退火铁合金，然后在转变范围内缓慢冷却。 |
| Velocity ratio | 速度比 |
1. The ratio between the input velocity to a machine, train of gears, etc. and the output velocity. 2. The ratio between the displacement of an applied force at one part of a mechanism and the movement of the load at a different part. 1.机器、齿轮系等的输入速度与输出速度之间的比率。2.在机构的一个部分处施加的力的位移与在不同部分处的载荷的移动之间的比率。 |
| 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。 |
| 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。 |
| Bearing stress | 承受应力 |
The force per unit of bearing area. 每单位承载面积的力。 |
| Mass flow meter | 质量流量计 |
An instrument, such as a Coriolis flow meter, which measures the mass flow rate of a fluid flowing through a pipe or other duct, rather than its volume flow rate. 一种仪器，例如科里奥利流量计，一种测量流经管道或其他管道的流体的质量流率而不是其体积流率的仪器。 |
| Radial wave equation | 径向波动方程 |
A differential equation describing the transmission of a wave in a system with radial symmetry. 描述波在径向对称系统中传输的微分方程。 |
| Oxidizing flame | 氧化焰 |
A gas flame produced with excess oxygen in the inner flame. 在内部火焰中过量氧气产生的气体火焰。 |
| Stabilizing treatment | 稳定化处理 |
(1) Before finishing to final dimensions, repeatedly heating a ferrous or nonferrous part to or slightly above its normal operating temperature and then cooling to room temperature to ensure dimensional stability in service. (2) Transforming retained austenite in quenched hardenable steels, usually by cold treatment. (3) Heating a solution-treated stabilized grade of austenitic stainless steel to 870 to 900 °C (1600 to 1650 °F) to precipitate all carbon as TiC, NbC, or TaC so that sensitization is avoided on subsequent exposure to elevated temperature. （1）在精加工至最终尺寸之前，反复加热含铁或非铁零件至或略高于其正常工作温度，然后冷却至室温，以确保使用中的尺寸稳定性。（2）在淬火可淬硬钢中转变残余奥氏体，通常通过冷处理。（3）将固溶处理的稳定等级奥氏体不锈钢加热至870至900°C（1600至1650°F），使所有碳沉淀为TiC、NbC或TaC，从而避免在随后暴露于高温时敏化。 |
| Impact extrusion | 冲击挤压 |
The extrusion of separate components of soft metals whose properties permit the action to be performed quickly. 挤压单独的软金属组件，其特性允许快速执行操作。 |
| Brake fluid | 制动液 |
The hydraulic fluid used to transmit force to the pistons in disc brakes or the wheel cylinders in drum brakes. Requirements include a high boiling point and low hygroscopy. 用于将力传递到盘式制动器中的活塞或鼓式制动器中的轮缸的液压油。要求包括高沸点和低吸湿性。 |
| Alloy steels | 合金钢 |
Steels that contain alloying elements such as chromium, nickel, molybdenum, manganese, silicon, tungsten, and vanadium. These are added to improve properties such as the hardenability, toughness, strength, wear resistance, and corrosion resistance compared with those of plain-carbon steel. Low-alloy steels have a total alloy content (including carbon) of less than about 8%. They are hardenable and have strength up to 30% higher than plain-carbon steels. High-alloy steels contain considerably more alloy content and are developed for specific properties such as superior corrosion and chemical resistance. 含有铬、镍、钼、锰、硅、钨和钒等合金元素的钢。添加这些是为了提高与普通碳钢相比的淬透性、韧性、强度、耐磨性和耐腐蚀性等性能。低合金钢的总合金含量（包括碳）小于约8%。它们是可硬化的，强度比普通碳钢高出30%。高合金钢含有相当多的合金含量，并针对特定性能而开发，例如卓越的耐腐蚀性和耐化学性。 |
| High strength low alloy steels | 高强度低合金钢 |
(HSLA steels) Steels with various micro-alloying elements such as copper, nickel, chromium, molybdenum, niobium, titanium, and vanadium in small quantities that give improved strength (as high as 900 MPa) and corrosion properties compared with plain carbon steels. Improvements are due to grain refinement and precipitation hardening, better control of the chemistry during steel making, and accurate rolling temperatures. （HSLA钢）是含有各种微合金元素的钢，如少量的铜、镍、铬、钼、铌、钛和钒，与普通碳钢相比，具有更好的强度（高达900MPa）和腐蚀性能。这些改进归功于晶粒细化和沉淀硬化、炼钢过程中更好的化学控制以及精确的轧制温度。 |
| Cohesive zone | 凝聚力区 |
In fracture-mechanics modelling and simulation, the region at the crack tip over which an assumed traction (load-displacement) relation has to be overcome to permit initiation and propagation of a crack. 在断裂力学建模和模拟中，必须克服假定的牵引（载荷-位移）关系以允许裂纹萌生和扩展的裂纹尖端区域。 |
| Spring temper | 弹簧回火 |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength and hardness about two-thirds of the way from full hard to extra spring temper. 非铁合金和一些铁合金的一种回火，其特点是抗拉强度和硬度约为全硬回火到超弹性回火的三分之二。 |
| Slip | 滑落 |
Plastic deformation by the irreversible shear displacement (translation)of one part of a crystal relative to another in a definite crystallographic direction and usually on a specific crystallographic plane. Sometimes called glide. 晶体的一部分在一定的晶体学方向上相对于另一部分的不可逆剪切位移（平移）引起的塑性变形，通常在特定的晶体主义平面上。有时被称为滑翔。 |
| Natural unit system (n.u. system) | 自然单位制（n.u.制） |
A non-SI system of units, based on fundamental constants, used in high-energy and particle physics. The n.u. of speed is the speed of light in a vacuum, c0 = 299 792 458 m/s. 基于基本常数的非国际单位制，用于高能和粒子物理n.u.速度是真空中的光速，c0=299792458m/s。 |
| 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。 |
| Atmosphere | 大气 |
1. (atm) An obsolete (non-SI) unit of pressure equal to 101 325 Pa or 1.013 25 bar and approximately equal to the atmospheric pressure (barometric pressure) measured at mean sea level. 1.（atm）一种已被淘汰的（非SI）压力单位，等于101325Pa或1.01325bar，大约等于在平均海平面测量的大气压力（大气压）。 |
| Shoulder screw | 轴肩螺钉 |
A screw having two or more diameters or shoulders and commonly used for supporting levers and other machine parts that have to operate freely. 一种具有两个或两个以上直径或轴肩的螺钉，通常用于支撑杠杆和其他必须自由操作的机器部件。 |
| True stress (σ) (Unit Pa) | 真应力（σ）（单位Pa） |
The value obtained by dividing the load applied to a member at a given instant by the cross-sectional area over which it acts. Compare with engineering stress. The applied load on a test specimen divided by the current cross-section area over which it acts. σ = s expε where s is the engineering stress given by the applied load divided by the original cross-section area over which it acts, and ε is the true strain. 通过将给定时刻施加在构件上的荷载除以其作用的横截面积而获得的值。与工程应力相比。施加在试样上的荷载除以其作用的当前横截面积。σ=s expε，其中s是由施加荷载除以其作用的原始横截面面积得出的工程应力，ε是真实应变。 |
| Pitch diameter | 中径 |
For screw threads, the diameter of an imaginary cylinder, the surface of which would pass through the threads at such points that would make the width of the groove and width of the land equal to one half the pitch. 对于螺纹，指一个假想圆柱体的直径，其表面将在使凹槽宽度和焊盘宽度等于螺距一半的点穿过螺纹。 |
| Alloy | 合金 |
1. A metallic material composed of two or more elements, one of which is usually a metal to which the other elements are added, e.g. iron-carbon or aluminium-copper (binary alloy); nickel-chromium-iron (ternary alloy). 2. A plastic produced as a blend of two or more immiscible polymers. This results in material that cannot be achieved by polymerization. 1.由两种或多种元素组成的金属材料，其中一种通常是添加了其他元素的金属，例如铁碳或铝铜（二元合金）；镍铬铁（三元合金）。2.由两种或多种不混溶聚合物混合而成的塑料。这导致无法通过聚合获得的材料。 |
| Inclusions | 夹杂物 |
Small pieces of nonmetallic impurities trapped within the base metal of. 存在于金属基体中的小块非金属杂质。 |
| Scale effect | 规模效应 |
The change in behaviour with size of a material, component, or structure. For example, cube-square scaling where one element changes with volume and another with area, as in the range of a projectile or ship, droplet formation, and fracture mechanics. 性能随材料、部件或结构尺寸的变化。例如，立方体平方比例，其中一个元素随体积变化，另一个元素因面积变化，如在射弹或飞船的射程、液滴形成和断裂力学中。 |
| Bolt blank | 螺栓毛坯 |
A rod on which a head has been formed, but on which no thread has been cut, from which bolts or screws may be made as required. 一种已形成头部但未切割螺纹的杆，可根据需要从中制造螺栓或螺钉。 |
| 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。 |
| Failure | 失效 |
The result when a body, component, or structure is incapable of performing the task for which it was designed. The term is often used without reference to what causes failure, such as fracture, buckling, excessive deformation, wear, or erosion. Failure criteria (failure theories, theories of strength) are mathematical expressions for the combinations of stress, strain, or strain energy at which materials fail, which are employed in design to dimension components. 主体、部件或结构无法执行其设计任务时的结果。该术语通常未提及导致失效的原因，如断裂、屈曲、过度变形、磨损或侵蚀。失效准则（失效理论、强度理论）是材料失效时应力、应变或应变能组合的数学表达式，用于部件尺寸设计。 |
| Thermoelastic effect | 热弹性效应 |
The change in temperature of material under adiabatic elastic deformation, e.g. when loading is so rapid that the material is not in thermal equilibrium with its surroundings. For most materials, elastic tension lowers the temperature and compression raises it. The reverse occurs in elastomers such as rubber that exhibit entropic elasticity because stretching reduces the number of possible molecular configurations and so reduces the entropy. The thermoelastic effect gives rise to a stress–strain hysteresis loop in cyclic elastic loading and is one mechanism by which vibrational energy is dissipated internally in materials. 材料在绝热弹性变形下的温度变化，例如当加载速度如此之快，以至于材料与其周围环境不处于热平衡时。对于大多数材料，弹性张力降低温度，压缩提高温度。相反的情况发生在弹性体中，如橡胶，其表现出熵弹性，因为拉伸减少了可能的分子构型的数量，从而降低了熵。热弹性效应在循环弹性载荷中产生应力-应变迟滞回线，是振动能量在材料内部耗散的一种机制。 |
| Degradation failure | 退化失效 |
Failure of a system, component, or structure owing to material degradation. 由于材料退化导致的系统、组件或结构失效。 |
| Hardness test | 硬度测试 |
1. Any of various tests in which different hard indenters are forced into the surface of a solid under different loads to give permanent impressions, the pressure to cause which being called the hardness. The Brinell test employs a spherical indenter; the Vickers test a square-based pyramid. The relation between indentation hardness H and uniaxial yield stress Y is approximately H = (2.5 ~ 3.0)Y. Originally hardnesses were given in kg/mm² but now are often given in Pa. 2. The tests for scratch and file hardness relate either to one material being able to mark another (Mohs hardness scale for minerals), or to the size of groove produced by a rigid indenter slid under load across a surface. 3. Rebound hardness concerns the height of rebound of a dropped indenter, or an indenter at the end of a pivoted arm, having struck a surface. 1.任何一种试验，其中不同的硬压头在不同载荷下压入固体表面，以产生永久压痕，所产生的压力称为硬度。布氏试验采用球形压头；维氏硬度测试是一个方形金字塔。压痕硬度H与单轴屈服应力Y之间的关系约为H=（2.5~3.0）Y。最初硬度以kg/mm²为单位，但现在通常在Pa.2中给出。划痕和锉刀硬度测试要么与一种材料能够标记另一种材料（矿物的莫氏硬度标度）有关，要么与刚性压头在表面上滑动产生的凹槽大小有关。3.回弹硬度涉及掉落压头或旋转臂端部压头撞击表面后的回弹高度。 |
| 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。 |
| Computer control | 电脑控制 |
The control of an engineering device or system by pre-programmed computer or by feedback control. 通过预编程计算机或反馈控制对工程设备或系统进行控制。 |
| Wind tunnel | 风洞 |
A duct in which a controlled flow of air is used for testing and research. Types include blow down, closed circuit, open return, and open section. Closed-circuit tunnels may be pressurized or evacuated. The working section is usually situated immediately downstream of the flow-conditioning elements, which may include a plenum chamber, honeycomb, screens, turbulence grids, and a contraction. Immediately downstream there is usually a diffuser. For basic research the usual requirement is for uniform steady flow in the working section with low swirl and turbulence intensity. For some applications the flow may be density stratified, sheared, unsteady, or of high turbulence intensity. 用于测试和研究的可控气流管道。类型包括排污、闭路、开路回路和开路段。闭路隧道可加压或排空。工作段通常位于流量调节元件的下游，可包括增压室、蜂窝、滤网、湍流格栅和收缩管。紧靠下游通常有一个扩散器。对于基础研究，通常的要求是在低涡流和湍流强度的工作段中实现均匀稳定流动。对于某些应用，流动可能是密度分层、剪切、不稳定或高湍流强度。 |
| 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。 |
| Inch (in) | 英寸（in） |
A non-SI unit of length now defined as 25.4 mm. The conversion to SI is 1 in = 2.54 × 10−2 m. 现在定义为25.4毫米的非SI长度单位。转换为SI为1in=2.54×10-2m。 |
| Edge distance ratio | 边距比 |
The ratio of the edge distance to the pin diameter in a bearing test. 轴承测试中边缘距离与销直径的比值。 |
| 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。 |
| 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。 |
| 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。 |
| Ball screw and nut | 滚珠丝杠和螺母 |
A nut and bolt assembly having semi-circular helical grooves, as opposed to threads, in which run ball bearings. On rotation of the nut, the balls move along the helix and carry the axial load. Balls reaching the end of the groove are recirculated back to the beginning. Such devices have low friction and very little backlash, and are used in some steering mechanisms. 一种螺母和螺栓组件，具有半圆形螺旋槽，与螺纹相反，在其中运行滚珠轴承。在螺母旋转时，滚珠沿螺旋线移动并承受轴向载荷。到达凹槽末端的滚珠被循环回起点。这种装置具有低摩擦和非常小的背隙，并且用于一些转向机构。 |
| Water quenching | 水淬 |
A quench in which water is the quenching medium. The major disadvantage of water quenching is its poor efficiency at the beginning or hot stage of the quenching process. 以水为淬火介质的淬火。水淬的主要缺点是在淬火过程的开始或热阶段效率低。 |
| Kilo (k) | 千（k） |
An SI unit prefix indicating a multiplier of 103; thus kilometre (km) is a unit of length equal to one thousand metres. 表示乘法器103的SI单位前缀；1千米是长度单位，等于1000米。 |
| 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。 |
| 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。 |
| Turbulent flow (turbulence) | 湍流 |
Fluid motion characterized by disorderly, rotational (i.e. vortical) three-dimensional velocity fluctuations covering a wide range of frequency and length scales. The pressure, temperature, and other fluid properties also fluctuate and the diffusion of heat, mass, and momentum is greatly enhanced. As are laminar and transitional flow, turbulent flow of a Newtonian fluid is governed by the Navier–Stokes equations which can in principle be solved by direct numerical simulation (DNS) in which all time and length scales of the fluctuating motion are resolved. 流体运动的特点是无序、旋转（即旋涡）三维速度波动，覆盖广泛的频率和长度尺度。压力、温度和其他流体特性也会波动，热、质量和动量的扩散会大大增强。与层流和过渡流一样，牛顿流体的湍流由Navier-Stokes方程控制，该方程原则上可以通过直接数值模拟（DNS）求解，在直接数值模拟中，波动运动的所有时间和长度尺度都可以求解。 |
| Compression failure | 压缩失败 |
The reduction or removal of a component’s load-bearing capacity in compression, caused by buckling, fracture, crease formation in fibre composites, etc. 由纤维复合材料中的屈曲、断裂、折痕形成等引起的部件在压缩中的承载能力的降低或消除。 |
| Celsius | 摄氏度 |
The temperature scale based on the freezing point of water (0ºC) and the boiling point of water (100ºC). The interval between these points is divided into 100 degrees. The scale was devised by Anders Celsius. 基于水的冰点（0ºC）和水的沸点（100ºC）的温标。这些点之间的间隔被划分为100度。这个比例是由安德斯·摄氏设计的。 |
| Screw machine | 螺丝机 |
A machine tool for high-volume manufacture of small turned components from rod or bar. 一种用棒或棒大批量制造小零件的机床。 |
| Equilibrium diagram | 平衡图 |
A graphical representation of the temperature, pressure and composition limits of phase fields in an alloy system as they exist under conditions of complete equilibrium. In metal systems, pressure is usually considered constant. 在完全平衡条件下，合金系统中相场的温度、压力和成分极限的图形表示。在金属系统中，压力通常被认为是恒定的。 |
| Pitch (Unit m) | 间距（单位：m） |
1. In a cascade of identical turbine or compressor blades, the distance between successive blades measured parallel to the leading edges. 2. For a screw thread, the distance between adjacent thread forms measured parallel to the thread axis. 3. For an aircraft, the vertical relationship between the nose and the horizon. The pitch axis is an axis in the plane of the wings of an aircraft, perpendicular to the centreline, about which the aircraft rotates. Pitch motion is the corresponding up or down movement of the aircraft nose. Pitch attitude is the angle between the centreline of an aircraft and the horizontal. The angle is positive when the nose is above its position when the centreline is horizontal. 1.在相同涡轮或压缩机叶片的叶栅中，平行于前缘测量的连续叶片之间的距离。2.对于螺纹，平行于螺纹轴线测量的相邻螺纹形状之间的距离。3.对于飞机，机头和水平线之间的垂直关系。俯仰轴是飞机机翼平面内垂直于中心线的轴，飞机绕中心线旋转。俯仰运动是飞机机头的相应向上或向下运动。俯仰姿态是飞机中心线与水平线之间的角度。当中心线水平时，当机头高于其位置时，角度为正。 |
| Standard gauge | 标准量规 |
A highly-accurate reference gauge against which to check working gauges. 一种高精度的基准量规，用于检查工作量规。 |
| 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。 |
| Water jacket | 水套 |
A casing, typically of sheet metal, surrounding a machine, such as an engine, that requires cooling. Water is circulated through the jacket and a heat exchanger where the heat is removed. 机壳一种机壳，通常由金属板制成，围绕着需要冷却的机器，如发动机。水通过夹套和热交换器循环，在热交换器中热量被去除。 |
| Cotter pin | 开口销 |
(cotter) 1. A tapered wedge or pin passing through a tapered slot or hole in one member and bearing against a second member to fix it in location. 2. A split cotter is commonly called a split pin. A pin with two legs. With legs together, the pin is placed through the hole in a clevis pin. The legs are then opened outward to prevent the cotter pin from backing out of the hole. The cotter pin, in turn, prevents the load-bearing clevis pin from backing out of its retaining hole. （开口）1.锥形楔子或销钉穿过一个构件中的锥形槽或孔，并支撑在第二个构件上以将其固定到位。2.开口开口通常称为开口销。相当于有两条腿的别针，将支腿放在一起，销钉穿过U形夹销上的孔。然后将支腿向外打开以防止开口销从孔中退出。开口销反过来防止承重U形夹销从其固定孔中退出。 |
| Rated flow (Unit m³/s or kg/s) | 额定流量（单位：m³/s或kg/s） |
In a hydraulic system or machine, the volume or mass flow rate a manufacturer specifies for a component as the maximum desirable for it to function as designed. 在液压系统或机器中，制造商为部件指定的体积或质量流量是其按设计运行所需的最大值。 |
| Rivet | 铆钉 |
A short rod with a head on one end that is inserted through aligned holes in plates to be joined, after which a second head is made on the protruding shank by hammering or forming. The most common head shapes are flat, domed, and inverse conical. In an array, the rivet pitch is the distance between the centres of adjacent rivets. Failure may occur by different mechanisms or modes. A one piece fastener consisting of a head and a body and used for fastening two or more pieces together by passing the body through a hole in each piece and then forming a second head on the body end. It cannot be removed except by taking off the head. 一种一端有头的短杆，插入待连接板上对齐的孔中，然后通过锤击或成型在突出的杆身上制作第二个头。最常见的头部形状是扁平、圆顶和倒锥形。在阵列中，铆钉间距是相邻铆钉中心之间的距离。故障可能由不同的机制或模式发生。一种一体式紧固件，由头部和主体组成，用于将两个或多个部件紧固在一起，方法是将主体穿过每个部件上的孔，然后在主体端部形成第二个头部。除非取下头部，否则无法移除。 |
| 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。 |
| Translational joint | 平移铰 |
A robot joint where the controlled variable is straight line movement. 控制变量为直线运动的机器人关节。 |
| Wing nut | 蝶形螺母 |
A nut having two opposite protruding wings to permit hand tightening. 一种螺母，有两个相对突出的翼片，可以用手拧紧。 |
| 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。 |
| Residual strength (Unit N) | 剩余强度（单位：N） |
The strength of a damaged body containing defects induced by microcracking, thermal shock, etc. 包含由微裂纹、热冲击等引起的缺陷的受损体的强度。 |
| Fatigue limit for p % survival | p%存活率的疲劳极限 |
The limiting value of fatigue strength for p%survival as the number of stress cycles becomes very large; pmay be any number, such as 95, 90, etc. 随着应力循环次数的增加，p%存活率的疲劳强度极限值变得非常大；p可以是任何数字，例如95、90等。 |
| 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。 |
| Columnar structure | 柱状结构 |
A coarse structure of parallel elongated grains formed by unidirectional growth, most often observed in castings, but sometimes in structures resulting from diffusional growth accompanied by a solid-state transformation. 由单向生长形成的平行细长晶粒的粗略结构，最常见于铸件中，但有时也出现在伴随固态转变的扩散生长产生的结构中。 |
| 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。 |
| Bright annealing | 光亮退火 |
Annealing in a protective medium to prevent discoloration of the bright surface. 在保护介质中退火以防止光亮表面变色。 |
| Forced-air quench | 强制空气淬火 |
A quench utilizing blasts of compressed air against relatively small parts such as a gear. 利用压缩空气冲击相对较小的零件（例如齿轮）进行的淬火。 |
| Failure of the joint | 连接失效 |
Failure of a bolted joint to behave as intended by the designer. Failure can be caused or accompanied by broken or lost bolts, but can also mean joint slip or leakage from a gasketed joint even if all bolts still remain whole and in place. Common reasons for joint failure include vibration loosening, poor assembly practices, improper design, unexpected service loads or conditions, etc. 螺栓连接未达到设计者的预期性能。故障可能由螺栓断裂或丢失引起或伴随而来，但也可能意味着即使所有螺栓仍保持完整和就位，也存在接头滑动或垫圈接头泄漏。接头故障的常见原因包括振动松动、装配不当、设计不当、意外的工作负载或条件等。 |
| Left hand screw | 左螺旋 |
One that screws into the mating part or advances when turned to the left or counter clockwise. 旋入配合部分或向左或逆时针旋转时前进的螺钉。 |
| 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。 |
| Coefficient of discharge (CD) | 流量系数（CD） |
For flow through a nozzle or orifice plate, the ratio of the actual mass flow rate to the theoretical mass flow rate calculated assuming the flow to be isentropic. The coefficient of velocity (velocity coefficient) is the corresponding ratio of the actual average velocity to the theoretical value. For incompressible flow, the theoretical flow rate and velocity can be calculated using Bernoulli’s equation. 对于通过喷嘴或孔板的流量，实际质量流量与假设流量为等熵计算的理论质量流量之比。速度系数（速度系数）是实际平均速度与理论值的对应比。对于不可压缩流，可以使用伯努利方程计算理论流量和速度。 |
| Impact testing | 冲击测试 |
Determination of the mechanical properties of materials under high-rate conditions. Often determined from the behaviour of a testpiece when struck by a pendulum or a weight falling from a known height, or when sandwiched between two Hopkinson bars. 在高速条件下测定材料的机械性能。通常根据测试件在被钟摆撞击或从已知高度坠落的重物或夹在两个霍普金森棒之间时的行为来确定。 |
| 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。 |
| Stress raisers | 局部应力集中 |
Changes in contour or discontinuities in structure that cause local increases in stress. 导致局部应力增加的轮廓变化或结构不连续性变化。 |
| Extensometer | 引伸计 |
An instrument for measuring changes in length over a given gage length caused by application or removal of a force. Commonly used in tension testing of metal specimens. Any instrument which measures the change in length of a part as the part is loaded. 一种用于测量在给定标距上由施加或移除力引起的长度变化，在零件加载时测量零件长度变化的仪器。常用于金属试样的拉力试验。 |
| 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。 |
| Condensing boiler | 冷凝锅炉 |
A relatively small industrial or domestic boiler that burns sulfur-free natural gas so that the products of combustion do not contain sulfuric acid and can be allowed to condense on heat-transfer surfaces without danger of corrosion. 一种相对较小的工业或家用锅炉，燃烧无硫天然气，因此燃烧产物不含硫酸，并且可以在传热表面上冷凝而没有腐蚀的危险。 |
| Absolute stability | 绝对稳定 |
Condtion of a linear system in which there exists a limiting value of the open-loop gain such that the system is stable for all lower values of that gain, and unstable for all higher values. 线性系统的条件，其中存在开环增益的限制值，使得系统对于该增益的所有较低值都是稳定的，而对于所有较高值来说都是不稳定的。 |
| Thermoelectric junction | 热电结 |
A welded, soldered, or twisted connection between the ends of two wires of dissimilar metals, as in a thermocouple. 两根不同金属线的末端之间的焊接、锡焊或绞合连接，如热电偶。 |
| Eutectoid | 共析 |
(1) An isothermal reversible reaction in which a solid solution is converted into two or more intimately mixed solids on cooling, the number of solids formed being the same as the number of components in the system. (2) An alloy having the composition indicated by the eutectoid point on an equilibrium diagram. (3) An alloy structure of intermixed solid constituents formed by a eutectoid reaction. （1）一种等温可逆反应，其中固溶体在冷却时转化为两种或两种以上紧密混合的固体，形成的固体数量与系统中组分的数量相同。（2）具有平衡图上共析点所示成分的合金。（3）由共析反应形成的混合固体成分的合金结构。 |
| Tightness parameter | 密封参数 |
A dimensionless parameter which defines the mass leakage of a gasket as a functionof contained pressure and a contained fluid constant. 一种无量纲参数，将垫圈的质量泄漏定义为所含压力和所含流体常数的函数。 |
| 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。 |
| Surface roughness (roughness) | 表面粗糙度 |
The small-scale, irregular peaks and troughs in a solid surface which are quantified using a surface analyser. Roughness may be a consequence of wear and corrosion, or of the manufacturing process. It leads to increased friction in solid– solid contact or fluid flow over a surface. Errors of form and waviness are excluded, but surface texture includes roughness and waviness. Surface topography incorporates the small-scale, three-dimensional geometry of a surface including surface roughness, machined, and etched features, typically at sub-mm scales. 固体表面中的小尺度不规则峰谷，使用表面分析仪进行量化。粗糙度可能是磨损和腐蚀或制造过程的结果。它会导致表面上的固-固接触或流体流动中的摩擦增加。不包括形状和波纹度误差，但表面纹理包括粗糙度和波纹度。表面形貌包括表面的小尺度三维几何结构，包括表面粗糙度、机加工和蚀刻特征，通常为亚毫米尺度。 |
| Coefficient of rolling friction | 滚动摩擦系数 |
The ratio of force parallel to a surface, on which an object rolls, to the normal force. Unlike sliding friction, rolling friction depends on the size of the contact patch and the radius of the rolling element, and the behaviour depends on whether the contact is elastic, viscoelastic, or plastic and on hysteresis losses. 平行于物体滚动表面的力与法向力之比。与滑动摩擦不同，滚动摩擦取决于接触片的大小和滚动元件的半径，其行为取决于接触是弹性的、粘弹性的还是塑性的以及滞后损失。 |
| Alloying element | 合金元素 |
Component added deliberately with the aim of improving the properties of an alloy. Alloying elements can affect the existence range of equilibrium phases present in an unalloyed material, or lead to the occurrence of new phases, or both. In addition, alloying elements strongly affect the kinetics of phase transformations and thus the microstructure formation in alloyed materials. 为改善合金性能而有意添加的成分。合金元素可以影响非合金材料中存在的平衡相的存在范围，或导致新相的出现，或两者兼而有之。此外，合金元素强烈影响相变动力学，从而影响合金材料的微观结构形成。 |
| 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。 |
| Rotary blower | 旋转鼓风机 |
(rotary compressor) A positive-displacement gas compressor which may be of the blade type, helical-screw type, meshing-lobe type (the Roots blower), or sliding-vane type. （旋转式压缩机）一种容积式气体压缩机，可以是叶片式、螺旋式、啮合凸角式（罗茨鼓风机）或滑动叶片式。 |
| SI system | SI国际单位制 |
SI is an abbreviation of Système International d’Unités, i.e., the international unit measurement system – an internationally established system of measurement units built on older metric systems. SI是Système International d‘Unités的缩写，即国际单位计量系统——一种基于旧公制的国际公认计量单位系统。 |
| 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。 |
| Pressure loss (Unit Pa) | 压力损失（单位Pa） |
The loss in stagnation pressure in internal flow due to wall friction and minor losses in fittings. 壁面摩擦引起的内部流动停滞压力损失和配件的微小损失。 |
| Creep modulus (Unit Pa) | 蠕变模量（单位Pa） |
The ratio of stress/strain at a chosen strain level obtained from creep tests, often plotted against time to show changes in stiffness. 从蠕变测试中获得的选定应变水平下的应力/应变比，通常随时间绘制以显示刚度的变化。 |
| Notch strength | 缺口强度 |
The maximum load on a notched tensile-test specimen divided by the minimum cross-sectional area (the area at the root of the notch). Also known as notch tensile strength. 缺口拉伸试样上的最大载荷除以最小横截面积（缺口根部的面积）。也称为缺口抗拉强度。 |
| Metric ton (tonne, t) | 公制吨（吨，t） |
An SI-accepted, but non-SI, unit of mass defined as 1 t = 103 kg. SI系统可接受但非国际单位制的质量单位，定义为1t=103kg。 |
| Density | 密度 |
The mass per unit volume of a solid material. (mass density, ρ) (Unit kg/m³) The mass per unit volume of a substance that satisfies the continuum assumption. The reciprocal of specific volume. 固体材料每单位体积的质量。（质量密度，ρ）（单位kg/m³）满足连续统假设的物质每单位体积的质量。和比容相关联。 |
| Embedment | 嵌入 |
Localized plastic deformation in heavily loaded fasteners allows one part to sink into, or smooth the surface of, a softer or more heavily loaded second part. Nuts embed themselves in joint surfaces. Bolt threads embed themselves in nut threads, etc. 重载紧固件中的局部塑性变形允许一个零件陷入较软或更重载的第二零件中，或使其表面光滑。螺母嵌入接合面中。例如螺栓螺纹嵌入螺母螺纹等。 |
| Contact strength (Unit N) | 接触强度（单位N） |
The maximum allowable load between contacting bodies converted into a stress. 换算成应力的接触体之间的最大允许载荷。 |
| Absolute rating | 绝对标称值 |
A theoretical size designation which is an estimation of the largest particle, by length, that can pass through a filter with a specific 一个理论尺寸名称，它是按长度估算的最大颗粒，它可以通过具有特定过滤器的过滤器 |
| Steel-wire rope | 钢丝绳 |
A rope or cable made up of many steel strands wrapped helically about an axis, each strand being made of metal wires twisted together like a helix. 一种绳索或缆绳，由许多绕轴螺旋缠绕的钢绞线组成，每根钢绞线由金属丝缠绕在一起形成螺旋。 |
| Screw area (Unit m²) | 螺丝面积（单位m²） |
The area of a circle described by the tips of a propeller. 螺旋桨尖端所描述的圆的面积。 |
| Fatigue | 疲劳 |
The phenomenon leading to fracture under repeated or fluctuating stresses having a maximum value less than the ultimate tensile strength of the material. Fatigue failure generally occurs at loads that, applied statically, would produce little perceptible effect. Fatigue fractures are progressive, beginning as minute cracks that grow under the action of the fluctuating stress. A term referring, in components and structures subjected to either random or cyclic periodically-varying loads, to a progressive reduction in strength leading to failure at stresses lower than those that cause failure under monotonic loading. Variable loads arise from outof-balance machinery and other vibration sources, wind gusts, etc., and a large proportion of service failures is caused by fatigue. Fatigue results from the initiation and slow propagation of cracks. In manufactured components, crack initiation usually occurs at a point of stress concentration. After a period, often of millions of stress cycles, the crack reaches a critical length at which the next peak load causes sudden brittle or ductile fracture. Fracture surfaces resulting from fatigue display characteristic striations or progression marks emanating from the crack initiation site during the slow crack growth period, with a different surface appearance for the final fracture. 在最大值小于材料极限抗拉强度的重复或波动应力下导致断裂的现象。疲劳失效通常发生在静态施加的载荷下，不会产生明显影响。疲劳断裂是渐进性的，从在波动应力作用下生长的微小裂纹开始。在承受随机或周期性变化载荷的部件和结构中，指强度逐渐降低，导致在低于单调载荷下导致失效的应力下发生失效的术语。可变负载由失衡的机械和其他振动源、阵风等引起，大部分故障是由疲劳引起的。疲劳是裂纹萌生和缓慢扩展的结果。在制造部件中，裂纹萌生通常发生在应力集中点。在一段时间（通常是数百万次应力循环）后，裂纹达到临界长度，此时下一个峰值载荷会导致突然脆性或韧性断裂。疲劳产生的断裂表面在缓慢裂纹扩展期间显示出从裂纹萌生部位发出的特征条纹或进展标记，最终断裂的表面外观不同。 |
| Blank carburizing | 毛坯渗碳 |
Simulating the carburizing operation without introducing carbon. This is usually accomplished by using an inert material in place of the carburizing agent, or by applying a suitable protective coating to the ferrous alloy. 在不引入碳的情况下模拟渗碳操作。这通常通过使用惰性材料代替渗碳剂或通过在铁合金上施加合适的保护涂层来实现。 |
| Thread form | 螺纹形式 |
The cross-sectional shape of the threads, defining thread angle, root, and crest profiles, etc. Thread length Length of that portion of the fastener which contains threads cut or rolled to full depth. 螺纹的横截面形状，定义螺纹角度、齿根和齿冠轮廓等。螺纹长度：紧固件中包含全深度切割或轧制螺纹的部分的长度。 |
| Strength of bolt | 螺栓强度 |
An ambiguous term which can mean Ultimate strength or Proof load or Endurance limit or Yield strength. 一个模棱两可的术语，可表示极限强度或验证荷载或耐久极限或屈服强度。 |
| Testing machine | 试验机 |
A machine used to apply either a steady or oscillatory or impact load to a testpiece. The load may be tensile, compressive, shear, bending, or torsional. 用于向试件施加稳定或振荡或冲击载荷的机器。载荷可以是拉伸的、压缩的、剪切的、弯曲的或扭转的。 |
| Cavitation damage | 气蚀损坏 |
Erosion of a solid surface through the formation and collapse of cavities or bubbles in an adjacent liquid that contains vapor and/or gas. 通过在包含蒸汽和/或气体的相邻液体中形成空穴或气泡并破坏固体表面。 |
| 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。 |
| Flange bolt | 法兰螺栓 |
A bolt with a built in washer-like flange just below the head. 在头部下方带有内置垫圈状法兰的螺栓。 |
| Thermoelectric material | 热电材料 |
A material in which any of the thermoelectric phenomena, such as the Peltier, Seebeck, and Thomson effects, are especially strong. 一种热电现象特别强烈的材料，如珀尔帖效应、塞贝克效应和汤姆森效应。 |
| Sample variance (s²) | 样本方差（s²） |
The sum of the squares of the differences between each observed value and the sample average divided by the sample size minus one. It is a point estimate of the population variance. 每个观测值与样本平均值之差的平方和除以样本大小减1。它是总体方差的点估计。 |
| Stress-concentration factor (Kt) | 应力集中系数（Kt） |
A multiplying factor for applied stress that allows for the presence of a structural discontinuity such as a notch or hole; Kt equals the ratio of the greatest stress in the region of the discontinuity to the nominal stress for the entire section. Also known as theoretical stress-concentration factor. 施加应力的倍增系数，允许存在结构不连续性，如缺口或孔；Kt等于不连续区域的最大应力与整个截面的标称应力之比。也称为理论应力集中系数。 |
| Thermal fatigue | 热疲劳 |
Fatigue resulting from the presence of temperature gradients that vary with time in such a manner as to produce cyclic stresses in a structure. 由于温度梯度的存在而产生的疲劳，温度梯度随时间变化，从而在结构中产生循环应力。 |
| Width across flats | 平面宽度 |
A principal dimension of nuts, or of bolt heads. Work hardening The slight increase in hardness and strength produced when a body is loaded past its yield point. Also called strain hardening. 螺母或螺栓头的主要尺寸。加工硬化：当物体被加载超过其屈服点时，硬度和强度略有增加。也称为应变硬化。 |
| System engineering | 系统工程 |
A methodology which integrates all disciplines and specialty groups into a team effort, forming a structured development process that proceeds from concept to production to operation. 一种将所有学科和专业组整合到团队工作中的方法，形成从概念到生产再到运营的结构化开发过程。 |
| 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。 |
| Constant life diagram | 恒定寿命图 |
A plot of experimentally derived fatigue-life data; perhaps the most complex and complete of the popular charts used to represent such data. 实验得出的疲劳寿命数据图；可能是用于表示此类数据的最复杂和最完整的流行图表。 |
| 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。 |
| Ultimate strength | 极限应力 |
The maximum tensile strength a bolt or material can support prior to rupture. Always found in the plastic region of the stress–strain or force–elongation curve, and so is not a design strength. Also called Tensile strength and ultimate tensile strength. The maximum stress (tensile, compressive, or shear) a material can sustain without fracture, determined by dividing maximum load by the original cross-sectional area of the specimen. Also known as nominal strength or maximum strength. 螺栓或材料在断裂前可支撑的最大抗拉强度。总是出现在应力-应变或力-伸长率曲线的塑性区域，因此不是设计强度。也称为抗拉强度和极限抗拉强度。材料在不断裂的情况下能够承受的最大应力（拉伸、压缩或剪切），通过将最大载荷除以试样的原始横截面积来确定。也称为标称强度或最大强度。 |
| Dynamic modulus | 动态模量 |
The ratio of stress to strain under cyclic conditions (calculated from data obtained from either free or forced vibration tests, in shear, compression, or tension). 循环条件下的应力与应变之比（根据在剪切、压缩或拉伸中的自由或强制振动测试中获得的数据计算得出）。 |
| Alternative energy | 可替代能源 |
(alternate energy) Energy sources that are renewable and do not have the undesired consequences of fossil fuels and nuclear energy. （替代能源）可再生能源，不会产生化石燃料和核能的不良后果。 |
| Nonlinear behavior | 非线性行为 |
A fastener or joint system is said to exhibit nonlinear behavior when the relationship between the External load on the joint and deformation of the parts is nonlinear, or when the relationship between increasing Preload and deformation is nonlinear. 当接头上的外部载荷与零件变形之间的关系是非线性的，或者当增加的预载荷与变形之间的联系是非线性的时，可以说紧固件或接头系统表现出非线性行为。 |
| Permissible variation | 允许偏差 |
For testing machines, the maximum allowable error in the value of the quantity indicated. It is convenient to express permissible variation in terms of the percent error. 对于试验机，所示数量值的最大允许误差。用误差百分比表示允许偏差是很方便的。 |
| 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。 |
| Heat (q, Q) (Unit J) | 热量（q, Q）（单位J） |
A form of energy that is transferred across the boundary of a system at one temperature to another system (or the surroundings) at a different temperature by virtue of the temperature difference between them. Heat can be identified only as it crosses the boundary. A body can never be said to contain heat which is thus a transient phenomenon. 一种能量形式，由于它们之间的温差在一个温度下通过系统边界传递到另一个温度不同的系统（或环境）。只有当热量穿过边界时才能识别。一个物体不能说永远含有热量，这是一种瞬态现象。 |
| Morse taper | 莫氏锥度 |
A self holding, standard taper largely used on drilling tools, drilling machine spindles, and some lathes. 一种自持式标准锥度，主要用于钻孔工具、钻床主轴和一些车床。 |
| Pressure (p) (Unit Pa) | 压力（p）（单位Pa） |
In thermodynamics and fluid mechanics, the compressive force exerted by the fluid per unit area. The pressure exerted by a fluid on a surface acts normal to the surface. 在热力学和流体力学中，每单位面积流体施加的压缩力。流体施加在表面上的压力垂直于表面。 |
| Water-jet cutting | 水射流切割 |
Cutting of materials such as rock by means of a high-speed jet of water containing abrasive particles. 通过含有磨料颗粒的高速水射流切割岩石等材料。 |
| 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。 |
| Amontons friction | 阿蒙顿摩擦 |
(Coulomb friction) Friction between surfaces where the ratio of the frictional force F to the normal force N is constant and independent of the area in contact. （库仑摩擦）摩擦力F与法向力N之比恒定且与接触面积无关的表面之间的摩擦。 |
| Thread insert | 螺纹嵌件 |
(threaded bushing) Either a thin cylinder with an internal thread (and sometimes also an external thread) or a helical coil of wire, pressed or screwed into a hole to accept a bolt or screw. Used in material too soft or a component too thin to be threaded, to change one form of thread to another or to repair a damaged thread. （螺纹衬套）一种带有内螺纹（有时也有外螺纹）的薄圆柱体或螺旋形线圈，压入或拧入孔中以接受螺栓或螺钉。用于材料太软或部件太薄而无法螺纹连接，用于将一种形式的螺纹更换为另一种形式或修复损坏的螺纹。 |
| Fog quenching | 雾淬 |
Quenching in a fine vapor or mist. 在细蒸汽或薄雾中淬火。 |
| Creep limit (Unit Pa) | 蠕变极限（单位Pa） |
The maximum allowable stress under the action of which creep deformation of a material does not exceed a specified limit. 材料在其作用下的蠕变变形不超过规定限度的最大许用应力。 |
| Hardness | 硬度 |
A measure of the resistance of a material to surface indentation or abrasion; may be thought of as a function of the stress required to produce some specified type of surface deformation. There is no absolute scale for hardness; therefore, to express hardness quantitatively, each type of test has its own scale of arbitrarily defined hardness. Indentation hardness can be measured by Brinell hardness test, Rockwell hardness test, Vickers hardness test, Knoop hardness test, and the Scleroscope hardness test. The ability of a ductile material to resist permanent deformation. It is a measure of plastic flow properties determined principally by indentation testing, but scratch hardness and rebound hardness are also employed. hardness scales The different measures of hardness given by different tests, such as indentation pressure in the Brinell and in the Vickers hardness tests, and the different Rockwell hardness numbers. 测量材料对表面压痕或磨损的阻力；可以认为是产生某些特定类型的表面变形所需的应力的函数。硬度没有绝对刻度，因此为了定量表示硬度，每种类型的试验都有自己的任意定义硬度等级。压痕硬度可通过布氏硬度试验、洛氏硬度试验，维氏硬度试验和努氏硬度试验以及硬化镜硬度试验进行测量。延展性材料具有抵抗永久变形的能力，它是主要通过压痕测试确定的塑性流动性能的量度，也使用划痕硬度和回弹硬度。硬度标度不同试验给出的不同硬度测量值，如布氏硬度试验和维氏硬度试验中的压痕压力，以及不同的洛氏硬度值。 |
| 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。 |
| Ratchet coupling | 棘轮联轴器 |
A joint employing a ratchet system between two shafts, so that not only does the driven shaft run in one direction only, but also the driven shaft can, if necessary, run more quickly than the driving shaft. 在两个轴之间采用棘轮系统的接头，这样不仅从动轴只能在一个方向上运行，而且在必要时，从动轴可以比驱动轴运行得更快。 |
| Length of engagement | 啮合长度 |
It is the axial measurement within which the external and internal threads have theoretical contact. 它是外螺纹和内螺纹具有理论接触的轴向测量。 |
| Starting friction | 起动摩擦 |
(limiting friction, static friction, stiction) (Unit N) The force required to initiate movement between two bodies in contact. （极限摩擦力、静摩擦力、粘滞）（单位N）在两个接触物体之间启动运动所需的力。 |
| Bolt gage | 螺栓量规 |
An ultrasonic instrument used to measure the stress or strain in bolts. 用于测量螺栓应力或应变的超声波仪器。 |
| Pitch-circle diameter (Unit m) | 节圆直径（单位：m） |
The diameter of the circle (the pitch circle) centred on a component’s axis, around which holes or bolts are equally spaced. 以部件轴为中心的圆（节圆）的直径，孔或螺栓围绕其等距分布。 |
| Finishing temperature | 终轧温度 |
The temperature at which hot working is completed. 完成热加工的温度。 |
| mechanical engineering | 机械工业 |
That branch of engineering concerned with energy conversion, stress analysis, vibration, dynamics, and kinematics, especially applied to design (machine design, mechanical-engineering design). 与能量转换、应力分析、振动、动力学和运动学有关的工程分支，尤其适用于设计（机器设计、机械工程设计）。 |
| Hot quenching | 热淬火 |
An imprecise term used to cover a variety of quenching procedures in which a quenching medium is maintained at a prescribed temperature above 70 °C (160 °F) 一个不精确的术语，用于涵盖各种淬火程序，其中淬火介质规定温度保持在70°C（160°F）以上。 |
| Vickers hardness number | 维氏硬度值 |
(diamond hardness number, DHN, VHN, VPN) (Unit kg/mm² originally, sometimes now Pa) Indentation hardness given by load divided by the surface area of the permanent impression obtained when the indenter is in the form of a square pyramid whose opposite faces make an angle of 136° with one another. The mean length d of the diagonals of the indentation is determined, from which VPN = 0.927(2W/d2) where W is the load, since the base of the pyramid has an area equal to 0.927 times the surface area. （金刚石硬度值，DHN，VHN，VPN）（最初单位为kg/mm²，有时为Pa）压痕硬度，由载荷除以永久压痕的表面积得出，当压头呈方形棱锥体形式时，其相对面彼此成136°角。确定压痕对角线的平均长度d，其中VPN=0.927（2W/d2），其中W是载荷，因为棱锥底部的面积等于表面积的0.92七倍。 |
| Screw | 螺钉 |
Threaded fastener designed to be used in a tapped or untapped (e.g., wood screw) hole, but not with a nut. A fastener with a screw thread cut or rolled into its cylindrical or conical shank, intended either to cut its own thread (as in a wood screw) or engage in a threaded hole. A self-tapping screw (sheet-metal screw, tapping screw) has a sufficiently hard thread that it cuts an internal thread in thin sheet or a component made of soft material when driven into a hole in the sheet or component. The screw head is the part of a screw used to apply torque to the screw. Common screw-head designs are circular in cross section with a diametral slot or cross, or hexagonal and recessed with a cross or hexagon. A screw thread is one or more continuous helical grooves of uniform section along either the exterior surface (male thread) or the interior surface (female thread) of a cylindrical or conical body. The three-dimensional shape that results when the thread cross section is rotated and axially advanced along an axis is called a helicoid, the angle that the thread makes when projected on to the axis being called the angle of inclination. Threads are employed in fasteners such as bolts, nuts, and screws; location and measuring instruments; in power drives; in some electrical fittings (Edison thread); and on the ends of crankshafts to suppress oil leakage (thrower thread). Parallel threads are formed on cylinders; tapered threads on cones, typically with a taper rate of 1:16. A screw with a righthanded thread appears to move away from the observer when turned clockwise. All standard screws, bolts and nuts have right-hand threads, but left-handed threads are sometimes employed. The axial distance between corresponding points on adjacent threads is called the screw pitch or screw rate and, for a single continuous helical groove (a single-start thread), is the same as the change in axial distance (the lead) between a nut and the head of a bolt during one revolution, the number of thread forms per mm then being the reciprocal of the pitch. For the same screw diameter, coarse threads have fewer threads per mm than fine threads. A multiple-start screw thread (usually coarse, see later) consists of two or more identical threads running simultaneously along its axis so as to provide greater bearing area and greater velocity ratio. The starts are separated by 180° (double start), 120° (triple start), 90° (quadruple start) etc., depending upon the number of threads. Thus, in double-start threads, the lead is twice the pitch; and so on. The axial distance between corresponding points on two adjacent threads in a multiple start thread is called the divided pitch. The position on a screw thread where there is equal distance between the flanks on the solid part of the thread and in the space between the threads is the pitch point, the associated diameter of which is termed the pitch diameter. The basic nomenclature for threads, some of which is common with that for toothed gearing, is shown in the diagrams. A helix formed or cut on a cylindrical surface which may advance along the axis to the right or left. The helix may be single or multiple. 一种螺纹紧固件，设计用于攻丝或未攻丝（如木螺钉）孔，但不与螺母配合使用。其螺纹被切割或卷成圆柱形或锥形柄，用于切割自身螺纹（如木螺钉）或嵌入螺纹孔。自攻螺钉（钣金螺钉、自攻螺钉）具有足够硬的螺纹，当打入薄板或部件中的孔时，它会在薄板或软材料部件中切割内螺纹。螺钉头是螺钉的一部分，用于向螺钉施加扭矩。常见的螺钉头设计为横截面为圆形，带有直径槽或十字，或为六边形，并带有十字或六边形凹槽。螺纹是沿圆柱形或锥形体的外表面（外螺纹）或内表面（内螺纹）具有均匀截面的一个或多个连续螺旋槽。当螺纹横截面旋转并沿轴轴向前进时产生的三维形状称为螺旋面，螺纹投影到轴上时形成的角度称为倾角。螺纹用于紧固件，如螺栓、螺母和螺钉；定位和测量仪器；在动力驱动中；在一些电气配件中（爱迪生螺纹）；并安装在曲轴端部，以抑制漏油（抛掷器螺纹）。在圆柱体上形成平行螺纹；圆锥上的锥形螺纹，通常具有1:16的锥形率。当顺时针旋转时，具有右手螺纹的螺钉似乎会远离观察者。所有标准螺钉、螺栓和螺母都有右手螺纹，但有时使用左手螺纹。相邻螺纹上对应点之间的轴向距离称为螺距或螺纹率，对于单个连续螺旋槽（单个起始螺纹），与螺母和螺栓头之间的轴向间距（导程）在一周内的变化相同，每mm的螺纹形式数为螺距的倒数。对于相同的螺钉直径，粗螺纹的每毫米螺纹数少于细螺纹。多头螺纹（通常为粗螺纹，见下文）由两个或多个沿其轴线同时延伸的相同螺纹组成，以提供更大的承载面积和更大的速比。根据螺纹的数量，起点之间的间隔为180°（双起点）、120°（三起点）、90°（四起点）等。因此，在双起始螺纹中，导程是螺距的两倍；多起点螺纹中两个相邻螺纹上对应点之间的轴向距离称为分割螺距。螺纹上的位置，即螺纹实体部分的侧面和螺纹之间的空间之间的距离相等，即节点，其相关直径称为节径。图中显示了螺纹的基本术语，其中一些与齿轮传动的基本术语相同。在圆柱面上形成或切割的螺旋线，可沿轴线向右或向左前进。螺旋可以是单个或多个。 |
| Supercooling | 过冷 |
Cooling below the temperature at which an equilibrium phase transformation can take place, without actually obtaining the transformation. 在没有实际获得相变的情况下，冷却到可以发生平衡相变的温度以下。 |
| 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。 |
| Die screw | 模具螺丝 |
Tool used when threading cylindrical pieces beyond the capacity of a die plate. 对超出模板容量的圆柱件进行螺纹加工时使用的工具。 |
| 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。 |
| Wallner lines | Wallner线 |
A distinct pattern of intersecting sets of parallel lines, usually producing a set of V-shaped lines, sometimes observed when viewing brittle fracture surfaces at high magnification in an electron microscope. Wallner lines are attributed to interaction between a shock wave and a brittle crack front propagating at high velocity. Sometimes Wallner lines are misinterpreted as fatigue striations. 一组相交的平行线的独特图案，通常产生一组V形线，有时在电子显微镜下高倍观察脆性断裂表面时观察到。Wallner线归因于高速传播的冲击波和脆性裂纹前沿之间的相互作用。有时Wallner线被误解为疲劳条纹。 |
| Positive-displacement machine | 正排量机 |
A machine that incorporates pistons, valves, etc. to ensure positive admission and delivery of a working fluid and prevent undesired reversal of flow. This class of machine incorporates all reciprocating compressors and expanders and some types of rotary compressor, the Roots blower, agear pump, a lobe pump, and a vane pump. 包含活塞、阀门等的机器，以确保工作流体的正向进入和输送，并防止不期望的反向流动。这类机器包括所有往复式压缩机和膨胀机以及一些类型的旋转压缩机、罗茨鼓风机、抽水机、凸轮泵和叶片泵。 |
| Maraging steels | 马氏体时效钢 |
Very high-strength iron alloys named after ‘martensitic’ and ‘aging’. They contain nickel, chromium, cobalt, and molybdenum, and form martensite on air cooling with a strength of about 1 GPa. When reheated to about 500°C and aged for some hours, a room-temperature strength of some 2.4 GPa is reached. 以“马氏体”和“时效”命名的超高强度铁合金。它们含有镍、铬、钴和钼，在空气冷却下形成强度约为1GPa的马氏体。当再加热至约500°C并老化数小时时，室温强度达到约2.4GPa。 |
| Springback | 回弹 |
The extent to which metal tends to return to its original shape or contour after undergoing a forming operation. 金属在经历成形操作后趋于恢复其原始形状或轮廓的程度。 |
| 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。 |
| Ductility | 延展性 |
The ability of a material to deform plastically before fracturing. Measured by elongation or reduction in area in a tensile test, by height of cupping in a cupping test, or by the radius or angle of bend in a bend test. 材料在断裂前发生塑性变形的能力。通过拉伸试验中的伸长率或面积减少量、杯突试验中的杯突高度或弯曲试验中的弯曲半径或角度来测量。 |
| Dynamic mechanical measurement | 动态机械测量 |
A technique in which either the modulus and/or damping of a substance under oscillatory load or displacement is measured as a function of temperature, frequency, or time, or a combination thereof. 一种技术，其中在振荡载荷或位移下测量物质的模量和/或阻尼作为温度、频率或时间或其组合的函数。 |
| Barcol hardness test | 巴氏硬度测试 |
An indentation test, similar to the Shore hardness test but using a pointed indentor with a flat tip, used to determine the hardness of such materials as rigid plastics and composites. 一种压痕测试，类似于肖氏硬度测试，但使用带有扁平尖端的尖头压头，用于确定硬质塑料和复合材料等材料的硬度。 |
| Two-phase flow | 两相流 |
A flow in which two phases are present, for example gas bubbles in a liquid, liquid bubbles in another liquid with which it is immiscible, solid particles in a liquid or gas. 两相流动，例如液体中的气泡、与之不混溶的另一种液体中的液体气泡、液体或气体中的固体颗粒。 |
| Proof stress | 弹性极限应力 |
(1) The stress that will cause a specified small permanent set in a material. (2) A specified stress to be applied to a member or structure to indicate its ability to withstand service loads. （1）在材料中引起规定的小永久变形的应力。（2）施加在构件或结构上的规定应力，以表明其承受工作荷载的能力。 |
| Turbomachine | 涡轮机械 |
(rotodynamic machine) A machine in which there is a transfer of energy between a continuous stream of fluid and a component, called a rotor, rotating about a fixed axis. Fans and turbines (gas, hydraulic, steam, or wind) are turbomachines in which energy is transferred to the rotor, causing it to rotate. Pumps and compressors are turbomachines in which energy is transferred from the externally driven rotor to the fluid. （旋转动力机器）在连续的流体流和绕固定轴旋转的部件（称为转子）之间进行能量传递的机器。风扇和涡轮机（燃气、液压、蒸汽或风力）是涡轮机械，其中能量传递到转子，使其旋转。泵和压缩机是涡轮机械，其中能量从外部驱动的转子传递到流体。 |
| Screw compressor | 螺杆压缩机 |
A positive-displacement rotary compressor in which gas is progressively compressed by two intermeshing, counter-rotating, helical screws. 一种容积式旋转压缩机，其中气体由两个相互啮合、反向旋转的螺旋螺杆逐渐压缩。 |
| Ablative materials | 烧蚀材料 |
Materials, especially coating materials, designed to provide thermal protection to a body in a fluid stream through the loss of mass. 材料，尤其是涂层材料，旨在通过质量损失为流体流中的物体提供热保护。 |
| Spring clip | 弹簧夹 |
A clip made of a material such as spring steel which grips an inserted part. 由弹簧钢等材料制成的夹子，用于夹住插入的零件。 |
| Biaxial stress | 双轴应力 |
Generalized loading of a body in a single plane with no loading normal to it. 物体在一个平面内的广义载荷，没有垂直于它的载荷。 |
| V-block | V型块 |
A block having a 90° V-shaped recess; used in a workshop to hold round workpieces. 具有90°V形凹槽的块体；在车间里用来装圆形工件。 |
| Annealing carbon | 退火碳 |
Fine, apparently amorphous carbon particles formed in white cast iron and certain steels during prolonged annealing. Also called temper carbon. 白口铸铁和某些钢在长时间退火过程中形成的细小、明显的无定形碳颗粒。也称为回火碳。 |
| Shank | 螺杆 |
Portion of a bolt which lies under the head. 1. The stem of a tool, such as a broach, drill bit, reamer, or tap, which fits into a holder such as a chuck. 2. The stem of a rivet or the unthreaded part of a screw or bolt. 3. The shaft of a tool connecting the tip and the handle. 螺栓头部下方的部分。1.一种工具的柄部，如拉刀、钻头、铰刀或丝锥，可装入夹具（如卡盘）中。铆钉的杆或螺钉或螺栓的无螺纹部分。3.连接尖端和手柄的工具的轴。 |
| 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。 |
| Mechanical efficiency (η) | 机械效率（η） |
1. In general for a machine, the ratio of output work to input work. 2. For a compressor, the ratio of indicated power to shaft power; for a reciprocating engine or an expander, the ratio of shaft power to indicated power. 1.一般而言，机器的输出功与输入功之比。2.对于压缩机，指示功率与轴功率之比；对于往复式发动机或膨胀机，轴功率与指示功率之比。 |
| Milling | 铣削 |
A machining process, typically for metals and plastics, in which a multi-tooth rotary cutter removes material to produce flat or profiled surfaces, slots, grooves, etc. Milling is a machining process in which metal is removed by a rotating multiple-tooth cutter; each tooth removes a small amount of metal with each revolution of the spindle. Because both workpiece and cutter can be moved in more than one direction at the same time, surfaces having almost any orientation can be machined. 一种加工工艺，通常用于金属和塑料，其中多齿旋转刀具去除材料以产生平坦或异形表面、槽、槽等。金属由旋转多齿刀具去除；主轴每转一圈，每个齿都会去除少量金属。因为工件和刀具可以同时在多个方向上移动，所以几乎可以加工任何方向的表面。 |
| Shear strength (Unit Pa) | 抗剪强度（单位Pa） |
The maximum shear stress that can be withstood by a material either (a) before plasticity occurs or (b) before rupture. 材料在（a）塑性发生之前或（b）断裂之前能够承受的最大剪切应力。 |
| 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。 |
| Preload relaxation | 预载松弛 |
Local yielding, due to excess bearing stress under nuts and bolt heads (caused by high local spots, rough surface finish, and lack of perfect squareness of bolt and nut bearing surfaces), may result in preload relaxation after preloads are first applied to a bolt. 由于螺母和螺栓头下的轴承应力过大（由局部斑点高、表面粗糙以及螺栓和螺母轴承表面缺乏完美的方正度造成），局部屈服可能会在首次向螺栓施加预载荷后导致预载荷松弛。 |
| Die | 模具 |
1. A tool having an appropriately-shaped hole through which material may be extruded or drawn. 2. A tool employed in forging. 3. A block having the male or female shape employed in stamping operations. 4. A thick circular disc, driven by a die wrench, with internally-threaded cutting edges for producing a screw thread. A die wrench (die stock) holds a screw-cutting die and has two projecting arms for applying the torque necessary to cut the thread. A die having a hexagonal or square shape (die nut), driven by a spanner, is used in confined spaces where a die wrench cannot be rotated through a full circle. 1.一种具有适当形状的孔的工具，通过该孔可以挤压或拉伸材料。2.一种用于锻造的工具。3.一种用于冲压操作的具有阳或阴形状的块体。4.一种由模具扳手驱动的厚圆盘，具有用于产生螺纹的内螺纹切削刃。冲模扳手（冲模）装有一个螺旋切割模，并有两个突出臂，用于施加切割螺纹所需的扭矩。由扳手驱动的六边形或方形模具（模具螺母）用于模具扳手无法旋转一整圈的受限空间。 |
| 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。 |
| Creep rupture strength (Unit Pa) | 蠕变断裂强度（单位Pa） |
The fracture stress at the end of a creep test in metals and polymers, often plotted against time to give a stress-rupture curve. 金属和聚合物蠕变试验结束时的断裂应力，通常与时间作图以给出应力-断裂曲线。 |
| Raised-face flange | 凸面法兰 |
A flange which contacts its mating joint member only in the region in which the gasket is located. The flanges do not contact each other at the bolt circle. 仅在垫圈所在区域接触其配合接头构件的法兰。法兰在螺栓圆处不相互接触。 |
| Graham’s laws | 格雷厄姆定律 |
The laws stating that the rates of diffusion and effusion of a gas are inversely proportional to the square root of its density. 规定气体的扩散和渗出速率与其密度的平方根成反比的定律。 |
| Toughness (Unit J/m²) | 韧性（单位：J/m²） |
The ability of a metal to absorb energy and deform plastically before fracturing. 1. The ability of a material to resist crack initiation and propagation. 2. The ability of a material to absorb strain energy without fracturing. 金属在破裂前吸收能量和塑性变形的能力。1.材料抵抗裂纹萌生和扩展的能力。2.材料在不发生断裂的情况下吸收应变能的能力。 |
| 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。 |
| Transition temperature (Unit K) | 转变温度（单位K） |
(1) An arbitrarily defined temperature that lies within the temperature range in which metal fracture characteristics (as usually determined by tests of notched specimens) change rapidly, such as from primarily fibrous (shear)to primarily crystalline (cleavage) fracture. (2) Sometimes used to denote an arbitrarily defined temperature within a range in which the ductility changes rapidly with temperature. (transition point) 1. The temperature at which the mechanism of fracture in metal alloys having a face-centred cubic crystal structure changes from ductile void growth to brittle cleavage. 2. The temperature at which a material changes from one crystal state to another. （1） 任意定义的温度，位于金属断裂特性（通常通过缺口试样的试验确定）快速变化的温度范围内，如从主要纤维（剪切）断裂到主要结晶（解理）断裂。（2） 有时用于表示延性随温度快速变化的范围内的任意定义的温度。（转变点）1.具有面心立方晶体结构的金属合金的断裂机制从韧性孔洞生长转变为脆性解理的温度。2.材料从一种晶体状态转变为另一种晶体的温度。 |
| Trepanning | 开孔 |
Trepanning is a machining process for producing a circular hole or groove in solid stock, or for producing a disk, cylinder, or tube from solid stock, by the action of a tool containing one or more cutters (usually single-point) revolving around a center. 开孔是一种机械加工工艺，通过包含一个或多个围绕中心旋转的刀具（通常为单点）的作用，在实心坯料中制造圆孔或凹槽，或从实心坯料生产圆盘、圆柱体或管。 |
| Martensitic stainless steels | 马氏体不锈钢 |
Martensitic stainless steels are hardenable magnetic stainless steels that contain 9–18% chromium, 0.06–1.25% carbon, and typically up to about 2.5% in total of manganese, silicon, nickel, and molybdenum. They can be heat-treated such that martensite is the prime microconstituent, and are usually available in the annealed or quenched-and-tempered condition. They have excellent strength and high hardness, and good corrosion resistance. Uses include cutlery, surgical instruments, rifle barrels, steam turbine tubing and blading, jet engine components, hand tools, machine parts, fasteners, valves, springs, bearings, pump shafts, nozzles, mining equipment, and wear-resistant parts. 马氏体不锈钢是一种可硬化的磁性不锈钢，其铬含量为9-18%，碳含量为0.06-1.25%，锰、硅、镍和钼的总含量通常高达约2.5%。它们可以进行热处理，使马氏体成为主要的微组分，通常可在退火或淬火回火条件下获得。它们具有优异的强度和高硬度，以及良好的耐腐蚀性。用途包括餐具、外科器械、步枪枪管、蒸汽轮机管道和叶片、喷气发动机部件、手动工具、机械零件、紧固件、阀门、弹簧、轴承、泵轴、喷嘴、采矿设备和耐磨零件。 |
| Cavitation tunnel | 空泡试验筒 |
A closed-circuit recirculating water tunnel in which the static pressure can be reduced to sufficiently low levels for cavitation studies to be performed. 一种闭路循环水隧洞，其中静压可降至足够低的水平，以便进行气蚀研究。 |
| 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。 |
| Fatigue test | 疲劳测试 |
A method for determining the range of alternating (fluctuating)stresses a material can withstand without failing. 一种确定材料可以承受而不会失效的交变（波动）应力范围的方法。 |
| 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。 |
| Crank pin | 曲柄销 |
It is a short shaft parallel to the axis of the crankshaft but radially offset from it, to which is attached the big end of a connecting rod in a bearing. Sometimes the crank pin is supported at one end only (a wrist pin) but in built-up or one-piece forged crankshafts, the crank pin is supported by thick plates (crank arms, crank webs) at either end. 它是一个短轴，平行于曲轴的轴线，但径向偏移，轴承中连杆的大端连接到该短轴上。有时曲柄销仅在一端支撑（腕销），在组合式或整体锻造曲轴中，曲柄销在两端由厚板（曲柄臂、曲柄腹板）支撑。 |
| 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。 |
| 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。 |
| Carbonitriding | 碳氮共渗 |
A case hardening process in which a suitable ferrous material is heated above the lower transformation temperature in a gaseous atmosphere of such composition as to cause simultaneous absorption of carbon and nitrogen by the surface and, by diffusion, create a concentration gradient. The process is completed by cooling at a rate that produces the desired properties in the workpiece. 一种表面硬化工艺，在该工艺中，将合适的含铁材料在气体气氛中加热到较低的转变温度以上，使其表面同时吸收碳和氮，并通过扩散形成浓度梯度。该工艺通过以在工件中产生所需性能的速率冷却来完成。 |
| Sound pressure (Unit μPa) | 声压（单位：μPa） |
The instantaneous deviation of pressure from the ambient pressure caused by the passage of a sound wave, which can be measured by a microphone in air and a hydrophone in water. 声波传播引起的压力与环境压力的瞬时偏差，可通过空气中的麦克风和水中的水听器测量。 |
| Cap nut | 盖型螺母 |
A nut with a blind threaded hole, for example a dome nut to cover the end of a bolt. 带有盲螺纹孔的螺母，例如用于覆盖螺栓末端的圆顶螺母。 |
| Zero initial conditions | 零初始条件 |
The assumption normally made in control engineering that up to a start time defined as t = 0, all variables have zero value. 在控制工程中通常作出的假设，即在定义为t=0的开始时间内，所有变量均为零值。 |
| Surface treatment | 表面处理 |
Any process, including chemical, electrochemical, mechanical, and thermal, designed to protect a surface against corrosion and wear or to alter its mechanical properties. 任何旨在保护表面免受腐蚀和磨损或改变其机械性能的工艺，包括化学、电化学、机械和热处理。 |
| Actual cubic feet per minute | 实际立方英尺每分钟 |
(acfm) An obsolete (i.e. non-SI) measure of volumetric flow rate; the volume of a gas flowing per minute at actual operating pressure and temperature, as opposed to the corresponding volume flow rate at STP. （acfm）已被淘汰的（即非SI）体积流量测量；在实际工作压力和温度下每分钟流动的气体体积，与STP下的相应体积流量相反。 |
| Quick coupling | 快速接头 |
(quick disconnect, fast coupling) A hose connection allowing rapid assembly or disassembly and comprising a socket and a plug incorporating a springloaded locking mechanism. （快速断开、快速连接）一种软管连接，允许快速组装或拆卸，包括插座和带有弹簧加载锁定机构的插头。 |
| Lathe | 车床 |
A machine tool in which work, gripped in the headstock, is rotated against the cutting tool to produce turned, bored, faced, or threaded components. 一种机床，其中夹持在主轴箱中的工件靠着切削工具旋转，以生产车削、钻孔、端面或螺纹部件。 |
| 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。 |
| 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。 |
| Tangent screw | 微动螺旋 |
A worm screw used to adjust measuring instruments such as sextants and vernier callipers. 用于调整六分仪和游标卡尺等测量仪器的蜗杆。 |
| Stress-strain diagram | 应力-应变图 |
A graph in which corresponding values of stress and strain are plotted against each other. Values of stress are usually plotted vertically(ordinates or y-axis) and values of strain horizontally (abscissas or xaxis). Also known as deformation curve and stress-strain curve. 对应的应力和应变值相对绘制的图表。应力值通常垂直绘制（纵坐标或y轴），应变值水平绘制（横坐标或X轴）。也称为变形曲线和应力-应变曲线。 |
| Hot hardness | 热硬度 |
The hardness of materials at high temperatures, often used to rank the performance of cutting tools. 材料在高温下的硬度，常用来对刀具的性能进行排名。 |
| Metallurgy | 冶金 |
The study of the atomic, crystallographic, microstructural, mechanical, and physical properties of metallic elements and alloys and their applications. 研究金属元素和合金的原子、晶体学、微观结构、机械和物理特性及其应用。 |
| Thermal electromotive force | 热电动势 |
The electromotive force generated in a circuit containing two dissimilar metals when one junction is at a temperature different from that of the other. 当一个结处于不同于另一个结的温度时，在含有两种不同金属的电路中产生的电动势。 |
| 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。 |
| Grain size | 晶粒大小 |
A measure of the areas or volumes of grains in a polycrystalline metal, usually expressed as an average when the individual sizes are fairly uniform. In metals containing two or more phases, the grain size refers to that of the matrix unless otherwise specified. For metals, a measure of the areas or volumes of grains in a polycrystalline material, usually expressed as an average when the individual sizes are fairly uniform. In metals containing two or more phases, the grain size refers to that of the matrix unless otherwise specified. Grain sizes are reported in terms of number of grains per unit area or volume, average diameter, or as a grainsize number derived from area measurements. 多晶金属中晶粒的面积或体积的量度，通常表示为单个尺寸相当均匀时的平均值。在含有两相或多相的金属中，除非另有说明，晶粒尺寸是指基体的晶粒尺寸。多晶材料中晶粒的面积或体积的量度，通常表示为单个尺寸相当均匀时的平均值。在含有两相或多相的金属中，除非另有说明，晶粒尺寸是指基体的晶粒尺寸。晶粒尺寸以每单位面积或体积的晶粒数、平均直径或从面积测量得出的晶粒尺寸数来报告。 |
| Reverse engineering | 逆向工程 |
The disassembly of a machine, mechanism, system or device, measurement of its component parts, and identification of the materials used so that if required, a functioning replica can be produced. 拆卸机器、机构、系统或装置，测量其组成部分，并识别所用材料，以便在需要时可以生产出功能正常的复制品。 |
| Bioengineering | 生物工程 |
(biological engineering) The application of engineering principles to biology, medicine, agriculture, etc. （生物工程）工程原理在生物学、医学、农业等方面的应用。 |
| Boyle’s law | 波义耳定律 |
The product of the pressure of a gas p and its volume is constant at a given absolute temperature T. Together with Charles law, it yields the ideal gas equation p = Mrt where m is the mass of gas and R is the specific gas constant. The volume of a gas at constant temperature is inversely proportional to the pressure. This means that as pressure increases, the volume of a gas decreases. 在给定的绝对温度T下，气体的压力p与其体积的乘积是恒定的。与查尔斯定律一起，它产生了理想的气体方程p=Mrt，其中m是气体的质量，R是特定的气体常数。恒温下气体的体积与压力成反比。这意味着随着压力的增加，气体的体积会减少。 |
| Sample percentage | 样本百分比 |
The percentage of observed values between two stated values of the variable under consideration. It is a point estimate of the percentage of the population between the same two stated values. 所考虑变量的两个规定值之间的观测值百分比。它是对相同两个规定值之间的总体百分比的点估计。 |
| Mole number (N) | 摩尔数（N） |
The number of moles in a given mass m of a substance, equal to m divided by the molar mass of the substance. 摩尔数物质给定质量m中的摩尔数，等于m除以物质的摩尔质量。 |
| Strain hardening | 应变硬化 |
An increase in hardness and strengthcaused by plastic deformation at temperatures below the recrystallization range. Also known as work hardening. (workhardening) The increase in stress above the initial yield stress required to deform a metal to greater strains in the plastic range at temperatures below the recrystallization range (cold working). Unloading after some strain or work input gives a harder and stronger material. 在低于再结晶范围的温度下，塑性变形导致硬度和强度的增加。也称为加工硬化。（加工硬化）在低于再结晶范围（冷加工）的温度下，使金属在塑性范围内变形至更大应变所需的高于初始屈服应力的应力增加。在一定的应变或功输入后卸载，会得到更硬、更强的材料。 |
| 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。 |
| 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。 |
| Atmometer | 气压计 |
(atmidometer, evaporimeter) An instrument that measures the rate of evaporation of water from a surface into the atmosphere. （湿度计，蒸发计）测量水从表面蒸发到大气中的速率的仪器。 |
| Angularity | 角度 |
The underfaces of the nut and the bolt head should be exactly perpendicular to the thread or shank axes. If the angle between the face and the axis is, for example, 868 or 948, the fastener is said to have an angularity of 48 (sometimes called Perpendicularity). 螺母和螺栓头的底面应与螺纹或柄轴完全垂直。例如，如果面和轴之间的角度为868或948，则称紧固件的角度为48（有时称为垂直度）。 |
| Profile | 轮廓 |
The shape of a cross section of an object, such as an aerofoil or cam. 物体的横截面形状，如机翼或凸轮。 |
| Bearing area | 承载面积 |
The product of the pin (or hole) diameter and specimen thickness in a bearing test. (bearing surface) (Unit m²) The projected area of a hole, such as a rivet hole, that carries a transverse load. 轴承测试中销（或孔）直径和试样厚度的乘积。（承载面）（单位m²）承载横向载荷的孔（例如铆钉孔）的投影面积。 |
| Shear strength | 抗剪强度 |
The maximum shear stress that a material is capable of sustaining. Shear strength is calculated from the maximum load during a shear or torsion test and is based on the original dimensions of the cross section of the specimen. 材料能够承受的最大剪切应力。抗剪强度根据剪切或扭转试验期间的最大载荷计算，并基于试样横截面的原始尺寸。 |
| Spring load (Unit N) | 弹簧载荷（单位：N） |
A load exerted on a component by bending, compressing, extending, or twisting an attached spring. Mechanical energy stored in the spring can be released if any constraints on the component are removed. 通过弯曲、压缩、延伸或扭转连接的弹簧而施加在部件上的载荷。如果部件上的任何约束被移除，则可以释放弹簧中存储的机械能。 |
| 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。 |
| Tangent modulus | 切线模量 |
The slope of the stress-strain curve at any specified stress or strain. See also modulus of elasticity. 在任何规定的应力或应变下，应力-应变曲线的斜率。另见弹性模量。 |
| Connecting rod | 连杆 |
(con rod) A link that transmits power from one system to another, often changing linear to rotary motion, as in the rod connecting the piston to the crankshaft in a reciprocating compressor or pump or to the crankshaft in an internal-combustion engine, as in the diagram. The big end (bottom end) is the larger end that connects to the bearing on one of the crankpins of the crankshaft. The little end (small end) is joined by a gudgeon pin to the piston. （连杆）将动力从一个系统传递到另一个系统的连杆，通常由线性运动变为旋转运动，如图所示，连杆将活塞连接到往复式压缩机或泵的曲轴或内燃机的曲轴上。大端（底端）是连接到曲轴一个曲柄销上轴承的大端。小端（小端）通过活塞销连接到活塞上。 |
| Shoulder | 轴肩 |
The portion of a shaft, stepped component, or flanged component, where a change in diameter or other dimension occurs. Even for a nominal step change, in practice there will be a radius where shoulder and shaft meet in order to avoid too severe a stress concentration. 轴、阶梯部件或法兰部件的直径或其他尺寸发生变化的部分。即使是名义阶跃变化，在实践中，肩部和轴相交处也会有一个半径，以避免出现过严重的应力集中。 |
| Activation energy | 活化能 |
(Ea, U) (Unit kJ/mol) The minimum energy for a chemical reaction to occur or for processes such as diffusion to take place in crystals. （Ea, U）（单位kJ/mol）发生化学反应或在晶体中发生扩散等过程的最小能量。 |
| 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。 |
| Creep fatigue | 蠕变疲劳 |
The effects of combined creep and fatigue at high homologous temperatures in metals, and in other materials such as polymers having time-dependent behaviour. 金属和其他材料（例如具有时间相关行为的聚合物）在高同源温度下的组合蠕变和疲劳的影响。 |
| Condensate strainer | 冷凝水过滤器 |
A filter in a steam plant used to remove particulate matter from condensate before it is added to feedwater. 蒸汽设备中的过滤器，用于在将冷凝水添加到给水中之前去除冷凝水中的颗粒物。 |
| Young’s modulus | 杨氏模量 |
A term used synonymously with modulus of elasticity. The ratio of tensile or compressive stresses to the resulting strain. 与弹性模量同义的术语。拉伸或压缩应力与产生应变的比率。 |
| Carbon potential | 碳势 |
A measure of the ability of an environment containing active carbon to alter or maintain, under prescribed conditions, the carbon level of the steel. Note: In any particular environment, the carbon level attained will depend on such factors as temperature, time, and steel composition. 衡量含有活性碳的环境在规定条件下改变或保持钢的碳含量的能力。注意：在任何特定环境中，所达到的碳含量将取决于温度、时间和钢成分等因素。 |
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