| 词或词组 | 中文 | 英文解释中文解释 |
|---|---|---|
| R-curve/Resistance curve | 阻力曲线 |
In linear-elastic fracture mechanics, a plot of crack-extension resistance as a function of stable crack extension, which is either the difference between the physical crack size, or the effective crack size, and the original crack size. R-curves normally depend on specimen thickness and, for some materials, on temperature and strain rate. An increase in fracture toughness with crack propagation shown by rising plots of toughness vs growing crack length. 在线弹性断裂力学中，作为稳定裂纹扩展函数的裂纹扩展阻力图，即物理裂纹尺寸或有效裂纹尺寸与原始裂纹尺寸之间的差值。R曲线通常取决于试样厚度，对于某些材料，还取决于温度和应变率。是随着裂纹扩展，断裂韧性增加，表现为韧性与扩展裂纹长度的上升曲线。 |
| Radial engine | 径向发动机 |
A piston engine in which the cylinders are arranged radially around the crankshaft, a design commonly used in early aircraft engines. 气缸沿径向围绕曲轴布置的活塞式发动机，这种设计通常用于早期飞机发动机。 |
| Radial flow | 径向流 |
radial flow Fluid flow for which the principal direction of flow is either radially inward or radially outward relative to an axial direction. 径向流动流体流动的主要方向是径向向内或径向向外流动。 |
| Radial load (Unit N) | 径向负荷（单位：N） |
1. Centrifugal loading induced in a rotating body. 2. (through-wallthickness load) The radial component of loading arising from internal or external pressurization of a closed vessel. There will also be axial and hoop loading. 1.旋转体中产生的离心载荷。2.（贯穿壁厚载荷）由封闭容器的内部或外部加压产生的载荷的径向分量。还存在轴向和环向载荷。 |
| Radial marks | 径向标记 |
Lines on a fracture surface that radiate from the fracture origin and are visible to the unaided eye or at low magnification. Radial lines result from the intersection and connection of brittle fractures propagating at different levels. Also known as shear ledges. 断裂表面上的线，从断裂起点辐射，肉眼可见或在低放大率下可见。径向线是在不同层面上传播的脆性断裂相交和连接的结果。也称为剪切壁架。 |
| 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。 |
| Radial-flow compressor | 离心式压缩机 |
A compressor in which the working gas enters the machine axially and is compressed as it flows radially out through the impeller. 一种压缩机，其中工作气体轴向进入机器，并在通过叶轮径向流出时被压缩。 |
| Radian (rad) | 弧度（rad） |
A coherent derived SI unit defined as the plane angle subtended at the centre of a circle by an arc having a length equal to the radius. Thus 2π radians are equivalent to 360° and 1 rad ≈ 57.3°. 一种相干导出的国际单位制单位，定义为在圆心处被长度等于半径的弧对向的平面角。因此，2π弧度相当于360°和1弧度≈57.3°. |
| Radiation pressure (Unit μPa) | 辐射压力（单位：μPa） |
The pressure exerted on a surface exposed to any form of electromagnetic radiation. If the radiation is absorbed, it is equal to the power-flux density divided by the speed of light. 施加在暴露于任何形式电磁辐射的表面上的压力。如果辐射被吸收，它等于功率通量密度除以光速。 |
| Radiator | 散热器 |
A heat exchanger used to transfer thermal energy from one fluid to another for heating or cooling purposes. Despite the name, the principal mode of heat transfer is convection rather than radiation. In motor vehicles, water circulated through the engine block is cooled as it flows through the tubes of an air-cooled heat exchanger. In domestic radiators, hot water from a boiler is circulated through a heat exchanger with a large surface area which transfers heat to the surrounding air. 一种热交换器，用于将热能从一种流体传递到另一种流体，用于加热或冷却。尽管有这个名字，但热传递的主要方式是对流而不是辐射。在机动车辆中，通过发动机缸体循环的水在流经风冷热交换器的管道时被冷却。在家用散热器中，来自锅炉的热水通过具有大表面积的热交换器循环，该热交换器将热量传递给周围的空气。 |
| Radioactive heat (Unit J) | 放射性热（单位J） |
Thermal energy released from the nucleus of an atom such as uranium235 by fission due to the absorption of a neutron. Heat is also produced by radioactive decay. 铀235等原子核因吸收中子而裂变释放的热能。放射性衰变也会产生热量。 |
| Radiosity (J) (Unit W/m²) | 辐射度（J）（单位W/m²） |
The total radiation leaving a given surface per unit area, including emitted, reflected, and transmitted radiation. 每单位面积离开给定表面的总辐射，包括发射、反射和透射辐射。 |
| Radius of bend | 弯曲半径 |
The radius of the cylindrical surface of the pin or mandrel that comes in contact with the inside surface of the bend during bending. For free or semiguided bends to 180° in which a shim or block is used, the radius of bend is one-half the thickness of the shim or block. 在弯曲过程中与弯曲内表面接触的销或心轴的圆柱面半径。对于使用垫片或垫块的180°自由弯曲或半导向弯曲，弯曲半径为垫片或垫板厚度的一半。 |
| 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。 |
| Range of stress (Sr) | 应力范围（Sr） |
The algebraic difference between the maximum and minimum stress in one cycle—that is, Sr = Smax – Smin 一个循环中最大和最小应力之间的代数差，即Sr=Smax–Smin |
| 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。 |
| Ratchet marks | 棘轮痕 |
Lines on a fatigue fracture surface that result from the intersection and connection of fatigue fractures propagating from multiple origins. Ratchet marks are parallel to the overall direction of crack propagation and are visible to the unaided eye or at low magnification. 疲劳断裂面上由从多个源头传播的疲劳断裂的交叉和连接产生的线。棘轮标记与裂纹扩展的整个方向平行，肉眼或低倍镜下均可看到。 |
| 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。 |
| Rated load (Unit N) | 额定负荷（单位：N） |
The maximum load that a structure or component has been designed to carry. 结构或部件设计承受的最大荷载。 |
| Rated power (Unit kW or hp) | 额定功率（单位：千瓦或马力） |
(rated capacity, rated horsepower) The maximum power output that can be sustained continuously for any power-producing machine or system, such as an engine or a power plant. （额定容量、额定马力）任何发电机器或系统（如发动机或发电厂）可连续维持的最大功率输出。 |
| Recrystallization annealing | 再结晶退火 |
Annealing cold-worked metal to produce a new grain structure without phase change. 退火冷加工金属以产生新的晶粒结构而不发生相变。 |
| Recrystallization temperature | 再结晶温度 |
The approximate minimum temperature at which complete recrystallization of a cold-worked metal occurs within a specified time. 冷加工金属在规定时间内发生完全再结晶的近似最低温度。 |
| Reduction in area (RA) | 缩小面积（RA） |
The difference between the original cross-sectional area of a tensile specimen and the smallest area at or after fracture as specified for the material undergoing testing. Also known as reduction of area. 拉伸试样的原始横截面积与试验材料断裂时或断裂后的最小面积之间的差值，也称为减少面积。 |
| Refractory materials | 耐火材料 |
Metals or ceramics that do not melt when exposed to temperature above about 1 500°C or deteriorate rapidly in a continuous temperature above about 550°C. 当暴露于高于约1500°C的温度时不熔化或在高于约550°C的连续温度下快速劣化的金属或陶瓷。 |
| 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。 |
| Relative density | 相对密度 |
(specific gravity) The ratio of the density of a substance to that of a reference substance, such as water for liquids and solids, and dry air for gases. （比重）物质密度与参考物质密度之比，如液体和固体为水，气体为干燥空气。 |
| Relative humidity (ϕ) | 相对湿度（ψ） |
The ratio or percentage of the actual mass of moisture in a given volume of air at a given temperature to the maximum possible mass of moisture at the same temperature. 给定温度下给定体积空气中的实际水分质量与相同温度下的最大可能水分质量的比率或百分比。 |
| Relaxation | 松弛 |
The loss of tension, and therefore Clamping force, in a bolt and joint as a result of Embedment, vibration loosening, gasket creep, differential thermal expansion, etc. 由于嵌入、振动松动、垫圈蠕变、热膨胀差等原因，螺栓和接头中的张力损失，因此夹紧力损失。 |
| Relaxation curve | 松弛曲线 |
A plot of either the remaining, or relaxed, stress as a function of time. 剩余压力或松弛压力随时间变化的曲线图。 |
| Relaxation rate | 松弛率 |
The absolute value of the slope of a stress-relaxation curve at a given time. 给定时间应力松弛曲线斜率的绝对值。 |
| Relaxed stress | 松弛应力 |
The initial stress minus the remaining stress at a given time during a stress-relaxation test. 在应力松弛试验期间，初始应力减去给定时间的剩余应力。 |
| 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。 |
| Repeatability | 重复性 |
A term used to refer to the test-result variability associated with a limited set of specifically defined sources of variability within a single laboratory. 一个术语，用于指与单个实验室内一组有限的特定变异源相关的测试结果变异性。 |
| Reproducibility | 再现性 |
A term used to describe test-result variability associated with specifically defined components of variance obtained both from within a single laboratory and between laboratories. 一个术语，用于描述与从单个实验室内和实验室之间获得的具体定义的方差分量相关的测试结果可变性。 |
| Residual preload | 残余预载荷 |
The tension which remains in an unloaded bolted joint after Relaxation. 松弛后未加载螺栓连接中保持的张力。 |
| 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。 |
| Residual stress (Unit Pa) | 残余应力（单位Pa） |
Stresses that remain within a body as the result of thermal or mechanical treatment or both. (internal stress) An internal-stress system found in components that have experienced elastic unloading from non-uniform plastic-strain fields during manufacture. 由于热处理或机械处理或两者兼而有之而留在物体内的应力。（内应力）在制造期间从非均匀塑性应变场经历弹性卸载的部件中发现的内应力系统。 |
| Resistance factor | 阻力系数 |
Probabilistic factor representing the uncertainties in the designer’s estimate of the strength of a shear joint. Used in Load and resistance factor design. 概率系数，表示设计人员对剪切接头强度估计的不确定性。用于载荷和阻力系数设计。 |
| 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。 |
| 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。 |
| 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。 |
| Reverse pitch (Unit °) | 反向螺距（单位°） |
The pitch of a variable-pitch propeller that produces negative thrust. 产生负推力的变桨距螺旋桨的桨距。 |
| Right hand thread | 右旋螺纹 |
A screw thread which advances into the mating part when turned clockwise or to the right. 顺时针或向右转动时进入配合部件的螺纹。 |
| 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。 |
| Rockwell hardness number (HR) | 洛氏硬度值（HR） |
A number derived from the net increase in the depth of impression in a Rockwell hardness test as the load on an indenter is increased from a fixed minor load to a major load and then returned to the minor load. Rockwell hardness numbers are always quoted with a scale symbol representing the penetrator, load, and dial used. 当压头上的载荷从固定的小载荷增加到大载荷，然后返回到小载荷时，洛氏硬度试验中压痕深度的净增加值。洛氏硬度值总是用刻度符号引用，表示所用的穿透器、载荷和刻度盘。 |
| Rockwell hardness test | 洛氏硬度测试 |
An indentation-hardness test using a calibrated machine that utilizes the depth of indentation, under constant load, as a measure of hardness. A direct-reading hardness test based on depth of indentation, in which a minor load (typically 30 to 100 N) is applied before the major load (typically 120 to 1 500 N). There are different scales using conical or spherical indenters for different ranges of hardness. An indentation hardness test based on the depth of penetration of a specified penetrator into the specimen under certain arbitrarily fixed conditions. 使用校准机器进行的压痕硬度测试，该机器利用恒定载荷下的压痕深度作为硬度测量值。一种基于压痕深度的直读硬度测试，其中在主要载荷（通常为120至1500N）之前施加较小载荷（通常是30至100N）。对于不同的硬度范围，使用锥形或球形压头有不同的刻度。在某些任意固定条件下，基于指定穿透器穿透试样深度的压痕硬度试验。 |
| Rockwell superficial hardness test | 洛氏表面硬度试验 |
Same as Rockwell hardness test, except that smaller minor and major loads are used. 与洛氏硬度测试相同，只是使用较小的次要载荷和主要载荷。 |
| Rolled thread | 滚制螺纹 |
A thread formed by plastically deforming the surface of the blank rather than by cutting operations. Increases fatigue life and thread strength, but is not possible (or perhaps economical) on larger sizes. 通过塑性变形坯料表面而不是通过切割操作形成的螺纹。增加疲劳寿命和螺纹强度，但不太可能（或者说是经济上不太可能）用于较大的尺寸。 |
| Root diameter (Unit m) | 根部直径（单位：m） |
The diameter of the circle passing through the roots of teeth in gear teeth or screw threads. 穿过齿轮齿或螺纹中齿根的圆的直径。 |
| Roots blower | 罗茨鼓风机 |
(rotary-piston blower) A positive-displacement gas compressor with two meshing lobed rotors that rotate within a close-fitting casing. Commonly used as a supercharger. （旋转活塞鼓风机）一种容积式气体压缩机，具有两个啮合的凸角转子，在紧密配合的外壳内旋转。通常用作增压器。 |
| Rosette | 玫瑰形的结 |
Strain gages arranged to indicate, at a single position, strain in three different directions. 应变计布置成在单个位置指示三个不同方向的应变。 |
| 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。 |
| Rotary piston flow meter | 旋转活塞流量计 |
A rotary liquid flow meter in which a cylindrical rotor, eccentrically mounted within a cylindrical casing, the axes of the two cylinders being parallel, is caused to rotate by the liquid flow. The flow rate is determined from the number of rotations of the rotor in a given time. 一种旋转式液体流量计，其中偏心安装在圆柱形外壳内的圆柱形转子，两个圆柱体的轴线平行，由液体流引起旋转。流量由转子在给定时间内的转数确定。 |
| Rotary pump | 旋转泵 |
A positive-displacement pump that pumps a liquid by rotation of internal components, such as a gear pump, lobe pump (similar to a Roots blower), or progressivecavity pump. 通过内部部件的旋转来泵送液体的容积泵，如齿轮泵、凸轮泵（类似于罗茨鼓风机）或螺杆泵。 |
| Rotary valve (rotating valve) | 旋转阀 |
A cylindrical or conical plug in which there is a transverse hole through which fluid can flow when the hole is aligned with the adjacent piping. 一种圆柱形或锥形塞，其中有一个横向孔，当该孔与相邻管道对齐时，流体可通过该孔流动。 |
| Rotational joint (revolute joint) | 旋转关节 |
In robotics, a single degree-of-freedom joint where the controlled variable is the joint angle. 在机器人技术中，一种单自由度关节，其中受控变量为关节角度。 |
| Rotor | 转子 |
A part of a machine that rotates on a shaft (rotor shaft) about its own axis, such as the blade-carrying discs of a turbine, the blades of a helicopter, or the rotating parts of a Roots blower. 绕轴（转子轴）绕其自身轴线旋转的机器部件，如涡轮叶片、直升机叶片或罗茨鼓风机的旋转部件。 |
| Roughness | 粗糙度 |
The deviations from the wavy surface itself, caused by geometry of the cutting tool and its wear, machining conditions, microstructure of the workpiece, vibrations in the system, and so on. Surface roughness changes as a surface goes through the wearing-in process, but may then stabilize. 由刀具的几何形状及其磨损、加工条件、工件的微观结构、系统中的振动等引起的与波状表面本身的偏差。表面粗糙度随着表面经过磨合过程而变化，但随后可能会稳定下来。 |
| Rpm (N) | 转速（N） |
An abbreviation for revolutions per minute. It is a widely used non-SI unit for rotational speed. The corresponding angular velocity ω in rad/s is given by πN/30. Rps (revolutions per second) is also used, the angular velocity then being 2πN. 每分钟转数的缩写。它是一种广泛使用的转速非SI单位。相应的角速度ω，单位为rad/s，由πN/30给出。还使用Rps（每秒转数），此时角速度为2πN。 |
| Rubber hardness | 橡胶硬度 |
The indentation hardness of rubber-like materials in which the depth of indentation under load is measured. This is a measure of elastic moduli rather than yield stress as with ductile materials, since there is little, if any, permanent impression remaining on unloading rubbery materials. 测量负载下压痕深度的橡胶类材料的压痕硬度。这是对弹性模量的测量，而不是对韧性材料的屈服应力，因为卸载橡胶材料时几乎没有（如果有的话）永久压痕。 |
| Rupture stress | 断裂应力 |
The stress at failure. Also known as breaking stress. 失效时的应力。也称为破裂应力。 |