机械英语：各种工具的英语翻译toolbox 工具箱
bench 工作台
vice, clamp 虎钳 (美作：vise)
saw 锯
bow saw 弓锯
circular saw 圆锯 (美作：buzzsaw)
compass saw, scroll saw 钢丝锯
fretsaw 细锯
handsaw 手锯
chisel 口凿
cold chisel, burin 冰凿
gouge, firmer gouge 半圆凿
plane 刨子
moulding plane 型刨
jack plane 粗刨
rabbet plane 槽刨
drawknife 刮刀
scraper 三角刮刀
rasp 粗锉
file 锉
square 尺
miter 斜槽规
scriber 近线尺
set square, triangle 三角板brace 手拉曲柄锉
hand drill 手钻
drill, bit 钻,有柄钻gimlet, auger 钻,无柄钻countersink 锥口钻
gauge, marking gauge 量规hammer 锤
mallet 木槌
nail 钉
brad 平头钉
tack, stud 圆头钉
screw 螺丝钉
screwdriver 螺丝刀,改锥screw tap 螺丝攻
nail puller 拔钉器
ruler 尺
tape measure 卷尺
folding ruler 折尺
sandpaper, emery paper 砂纸toolbox 工具箱
bench 工作台
vice, clamp 虎钳 (美作：vise) saw 锯
bow saw 弓锯
circular saw 圆锯 (美作：buzzsaw) compass saw, scroll saw 钢丝锯fretsaw 细锯
handsaw 手锯
chisel 口凿
cold chisel, burin 冰凿
gouge, firmer gouge 半圆凿
plane 刨子
moulding plane 型刨
jack plane 粗刨
rabbet plane 槽刨
drawknife 刮刀
scraper 三角刮刀
SPSS 统计软件的主菜单及子菜单
spss软件的中英文翻译 Absolute deviation, 绝对离差 Absolute number, 绝对数 Absolute residuals, 绝对残差 Acceleration array, 加速度立体阵 Acceleration in an arbitrary direction, 任意方向上的加速度Acceleration normal, 法向加速度 Acceleration space dimension, 加速度空间的维数Acceleration tangential, 切向加速度 Acceleration vector, 加速度向量 Acceptable hypothesis, 可接受假设 Accumulation, 累积 Accuracy, 准确度 Actual frequency, 实际频数 Adaptive estimator, 自适应估计量 Addition, 相加 Addition theorem, 加法定理 Additivity, 可加性 Adjusted rate, 调整率 Adjusted value, 校正值 Admissible error, 容许误差 Aggregation, 聚集性 Alternative hypothesis, 备择假设 Among groups, 组间 Amounts, 总量 Analysis of correlation, 相关分析 Analysis of covariance, 协方差分析 Analysis of regression, 回归分析 Analysis of time series, 时间序列分析 Analysis of variance, 方差分析 Angular transformation, 角转换 ANOVA （analysis of variance）, 方差分析 ANOVA Models, 方差分析模型 Arcing, 弧/弧旋 Arcsine transformation, 反正弦变换 Area under the curve, 曲线面积 AREG , 评估从一个时间点到下一个时间点回归相关时的误差ARIMA, 季节和非季节性单变量模型的极大似然估计 Arithmetic grid paper, 算术格纸 Arithmetic mean, 算术平均数
Lesson 1 力学的基本概念 1、词汇： statics [st?tiks] 静力学；dynamics动力学；constraint约束；magnetic [m?ɡ＇netik]有磁性的；external [eks＇t?:nl] 外面的, 外部的；meshing啮合；follower从动件；magnitude [＇m?ɡnitju:d] 大小；intensity强度，应力；non-coincident [k?u＇insid?nt]不重合；parallel [＇p?r?lel]平行；intuitive 直观的；substance物质；proportional [pr?＇p?:??n?l]比例的；resist抵抗，对抗；celestial [si＇lestj?l]天空的；product乘积；particle质点；elastic [i＇l?stik]弹性；deformed变形的；strain拉力；uniform全都相同的；velocity[vi＇l?siti]速度；scalar[＇skeil?]标量；vector[＇vekt?]矢量；displacement代替；momentum [m?u＇ment?m]动量； 2、词组 make up of由……组成；if not要不，不然；even through即使，纵然； Lesson 2 力和力的作用效果 1、词汇： machine 机器；mechanism机构；movable活动的；given 规定的，给定的，已知的；perform执行；application 施用；produce引起，导致；stress压力；applied施加的；individual单独的；muscular [＇m?skjul?]]力臂；gravity[ɡr?vti]重力；stretch伸展，拉紧，延伸；tensile[tensail]拉力；tension张力，拉力；squeeze挤；compressive 有压力的，压缩的；torsional扭转的；torque转矩；twist扭，转动；molecule [m likju:l]分子的；slide滑动; 滑行；slip滑，溜；one another 互相；shear剪切；independently独立地，自立地；beam梁；compress压；revolve (使)旋转；exert [iɡ＇z?:t]用力，尽力，运用，发挥，施加；principle原则, 原理，准则，规范；spin使…旋转；screw螺丝钉；thread螺纹； 2、词组 a number of 许多；deal with 涉及，处理；result from由什么引起；prevent from阻止，防止；tends to 朝某个方向；in combination结合；fly apart飞散； 3、译文： 任何机器或机构的研究表明每一种机构都是由许多可动的零件组成。这些零件从规定的运动转变到期望的运动。另一方面，这些机器完成工作。当由施力引起的运动时，机器就开始工作了。所以，力和机器的研究涉及在一个物体上的力和力的作用效果。 力是推力或者拉力。力的作用效果要么是改变物体的形状或者运动，要么阻止其他的力发生改变。每一种
Mechatronics Electrical machinery and electronics, also known as the integration of science, English as Mechatronics, it is by English mechanics of the first half of Mechanics and Electronics of the latter part of a combination of Electronics. Mechatronics 1971, first appeared in Japanese magazine, "Machine Design" on the supplement, with the mechanical-electrical integration of the rapid development of technology, electromechanical integration, the concept was widely accepted and we have universal application. With the rapid development of computer technology and extensive application of mechatronics technology unprecedented development. Mechatronics present technology, mechanical and micro-electronics technology is closely a set of technologies, the development of his machine has been cold humane, intelligent. Specific mechanical and electrical integration technologies, including the following: (1) mechanical engineering machinery and technology is the basis of mechatronics, mechanical technology, focused on how to adapt to mechanical and electrical integration technologies, the use of other high and new technology to update the concept, the realization of the structure, materials, the performance changes to meet the needs to reduce weight, reduce the size and improve accuracy, increase the stiffness and improving the performance requirements. Mechatronic systems in the manufacturing process, the classical theory and technology of mechanical computer-aided technology should help, while the use of artificial intelligence and expert systems, the formation of a new generation of mechanical manufacturing technology. (2) Computer and Information Technology Which information exchange, access, computing, judge and decision-making, artificial intelligence techniques, expert system technology, neural networks are computer information processing technology. (3) System Technology System technology that is the concept of the overall application of related technology organizations, from the perspective of the overall objectives and systems will be interconnected into the overall number of functional units, system interface technology is an important aspect of technology, it is an organic part of the realization of system guarantee connectivity.
Unit1 1、What is the difference between an alloy and a pure metal? Pure metals are elements which come from a particular area of the periodic table. Examples of pure metals include copper in electrical wires and aluminum in cooking foil and beverage cans. 合金与纯金属的区别是什么？纯金属是在元素周期表中占据特定位置的元素。例如电线中的铜和制造烹饪箔及饮料罐的铝。 Alloys contain more than one metallic element. Their properties can be changed by changing the elements present in the alloy. Examples of metal alloys include stainless steel which is an alloy of iron, nickel, and chromium; and gold jewelry which usually contains an alloy of gold and nickel. 合金包含不止一种金属元素。合金的性质能通过改变其中存在的元素而改变。金属合金的例子有：不锈钢是一种铁、镍、铬的合金，以及金饰品通常含有金镍合金。 2、 Why are metals and alloys used? Many metals and alloys have high densities and are used in applications which require a high mass-to-volume ratio. 为什么要使用金属和合金？许多金属和合金具有高密度，因此被用在需要较高质量体积比的场合。 Some metal alloys,such as those based on aluminum, have low densities and are used in aerospace applications for fuel economy. Many alloys also have high fracture toughness, which means they can withstand impact and are durable. 某些金属合金，例如铝基合金，其密度低，可用于航空航天以节约燃料。许多合金还具有高断裂韧性，这意味着它们能经得起冲击并且是耐用的。 3、The atomic bonding of metals also affects their properties. In m etals, the outer valence electrons are shared among all atoms, and ar e free to travel everywhere. Since electrons conduct heat and electri city, metals make good cooking pans and electrical wires. 金属的原子连结对它们的特性也有影响。在金属内部，原子的外层阶电子由所有原子共享并能到处自由移动。由于电子能导热和导电，所以用金属可以制造好的烹饪锅和电线。 It is impossible to see through metals, since these valence electrons absorb any photons of light which reach the metal. No photons pass through. 因为这些阶电子吸收到达金属的光子，所以透过金属不可能看得见。没有光子能通过金属. 4、Some of the useful properties of ceramics and glasses include high melting temperature, low density, high strength, stiffness, hardness, wear resistance, and corrosion resistance. 陶瓷和玻璃的特性高熔点、低密度、高强度、高刚度、高硬度、高耐磨性和
工具英语 toolbox 工具箱 bench 工作台 vice, clamp 虎钳(美作:vise) saw 锯 bow saw 弓锯 circular saw 圆锯(美作:buzz saw) compass saw, scroll saw 钢丝锯fretsaw 细锯 handsaw 手锯 chisel 口凿 cold chisel, burin 冰凿 gouge, firmer gouge 半圆凿 plane 刨子 mounding plane 型刨 jack plane 粗刨 rabbet plane 槽刨 drawknife 刮刀 scraper 三角刮刀 rasp 粗锉 file 锉 square 尺 miter 斜槽规 scriber 近线尺 set square, triangle 三角板 brace 手拉曲柄锉 hand drill 手钻 drill, bit 钻,有柄钻 gimlet, auger 钻,无柄钻countersink 锥口钻 gauge, marking gauge 量规hammer 锤 mallet 木槌 nail 钉 brad 平头钉 tack, stud 圆头钉 screw 螺丝钉 screwdriver 螺丝刀,改锥 screw tap 螺丝攻 nail puller 拔钉器 ruler 尺 tape measure 卷尺 folding ruler 折尺sandpaper, emery paper 砂纸 spanner 扳子(美作:wrench) double-ended spanner 双头扳子 adjustable spanner, monkey wrench 活扳子,活络扳手 box spanner 管钳子(美作:socket wrench) calipers 卡规 pincers, tongs 夹钳 shears 剪子 wire cutters 剪线钳 multipurpose pliers, universal pliers 万能手钳adjustable pliers 可调手钳 punch 冲子 drill 钻 chuck 卡盘 scraper 三角刮刀 reamer 扩孔钻 caliper gauge 孔径规 hacksaw 钢锯 rivet 铆钉 nut 螺母 locknut 自锁螺母,防松螺母 bolt 螺栓 pin, peg, dowel 销钉 washer 垫圈 staple U形钉 grease gun 注油枪 oil can 油壶 jack 工作服 spade 锄 fork 叉子 shovel 铁锹,铲 rake 耙 roller 滚压器,碌碡 dibble 掘穴机 wheelbarrow 小车,独轮车 watering can 喷壶 garden hose, hosepipe 橡胶软管 lawnmower 剪草机 shears, garden shears 园艺剪刀 pruning shears 修枝剪 pruning knife 修枝刀 sickle 镰刀 scythe 钐刀,钐镰
外文翻译 英文原文 Belt Conveying Systems Development of driving system Among the methods of material conveying employed，belt conveyors play a very important part in the reliable carrying of material over long distances at competitive cost．Conveyor systems have become larger and more complex and drive systems have also been going through a process of evolution and will continue to do so．Nowadays，bigger belts require more power and have brought the need for larger individual drives as well as multiple drives such as 3 drives of 750 kW for one belt(this is the case for the conveyor drives in Chengzhuang Mine)．The ability to control drive acceleration torque is critical to belt conveyors’performance．An efficient drive system should be able to provide smooth，soft starts while maintaining belt tensions within the specified safe limits．For load sharing on multiple drives．torque and speed control are also important considerations in the drive system’s design. Due to the advances in conveyor drive control technology，at present many more reliable．Cost-effective and performance-driven conveyor drive systems covering a wide range of power are available for customers’ choices[1]. 1 Analysis on conveyor drive technologies 1．1 Direct drives Full-voltage starters．With a full-voltage starter design，the conveyor head shaft is direct-coupled to the motor through the gear drive．Direct full-voltage starters are adequate for relatively low-power, simple-profile conveyors．With direct fu11-voltage starters．no control is provided for various conveyor loads and．depending on the ratio between fu11-and no-1oad power requirements，empty starting times can be three or four times faster than full load．The maintenance-free starting system is simple，low-cost and very reliable．However, they cannot control starting torque and maximum stall torque；therefore．they are
钟平老师的机械翻译公式 2009-11-15 11:51 机械化英语翻译法 ————领航钟平老师基础版听课笔记 简介：本方法主要是运用数学的逻辑思维，将长难句进行划分层次，然后运用所总结的公式进行翻译。如果真正掌握后可以让语法近乎白痴的人在以后不会碰到翻译不了的句子，但切记：词汇是一切的根本。 一、英语之基本规则 主干先行(主、谓、宾)，废话后置(定、状) 二、主干的确定 构成一句话的主要条件是：主语+谓语 1> 谓语：a.划出所有动词；b.排除具有下列条件的动词：从句中的、句首状语、前面无助动词的分词、to do形式（谓语+to do
除外，因为它整体作谓语）、活用的动词（如动词当名词用） * 单词的活用能通过运用简单词，让写出来的句子收到意想不到的效果。 例：Chinese economy is bettering!(中国的经济越来越好） You were,are and will be in my heart.(你永远在我心中） 2> 主语： a.句首的第一个名词性结构； b.第一个谓语前的第一个名词性结构。 名词性结构：名词、代词、动名词、动词不定式、从句、It+……+从句/to do; 非名词性结构：介词短语中的名词性结构、从句中的名词性结构。 3> 宾语：每个谓语后面的名词性结构。
三、复杂英文模式之计算公式： [状语]+主语+(定语)+谓语+[小状语]+宾语+{定语或状语} 例：[Although not so world widely accepted],people (who are emotionally weak in daily business) are [often] losers {who are not able to fulfil any fruitful achievements in their lifetime that they endure}. 子公式(无宾语模式)：[状语]+主语+(定语)+谓语+[小状语] * 宾语后一般都是定语，除非一开始就有表示状语的概念（如程度、方式、目的、结果、原因等） 四、定状的汉化（核心） 1> 前提：分别划出各定状层次，包括：a.分词结构b.从句c.介词短语。 2> 状语的处理 规则1 汉化位置：句子首尾或最近的谓语前
1.我们可以把钢再次加热到临界温度以下的某一温度，然后在慢慢让其冷却。We can heat the steel again to a temperature below the critical temperature, then cool it slowly. 2.无论任何简单的机床，都是由单一元件即通称为机械零件或部件组成的。However simple, any machine is a combination of individual components generally referred to as machine elements or parts. 3.这些金属不都是好的导体。 All these metals are not good conductors. 4. 在做带电实验的时候，再怎么小心都不为过。 You can't be too careful in performing an experiment. 5.利用发电机可以把机械能转变成电能。 The mechanical energy can be changed back into electrical energy by means of a generator or dynamo. 6.假定电源输入的电压保持不变。 Assume that the voltage input of the power supply remains the same. 7.化石燃料是发电过程中最为频繁使用的能源。 Fossil fuels are most frequently used source daring the power generation process. 8单个机械零件的可靠性成为评估整台机器使用寿命的基本因素。 The individual reliability of machine elements becomes the basis for estimating the overall life 9.说我们生活在一个电子时代，这一点都不夸张。 It's no exaggeration to say that we live in an electronic age. 10.发动机的转速不应超过最大允许值。 Engine revolution should not exceed the maximum permissible. 11.如能从大型核电站获得成本极低的电力，电解氢的竞争能力就会增强。（Electrolytic hydrogen）。 If extremely low-cost power were ever to become available from large nuclear power plants, electrolytic hydrogen would become competitive. 12.电子技术提供了一种新的显示时间的方法。 A new way of displaying time has been given by electronics. 13.远距离输电需要高压，安全用电需要低压。 High voltage is necessary for long transmission line while low voltage for safe use. 14.铝的电阻大约是同等尺寸的铜的1.5倍。 The resistance of aluminum is approximately half again as great as that of copper for the same dimensions = size 15.In fact,it is impossible for no force to be exerted on a body,since in this world everything is subject to the for ce of gravity. 事实上，物体不受外力作用是不可能的，因为在这个世界上任何物体都要受到重力的作用。 16.In a thermal power plant,all the chemical energy is not
工具箱用英语怎么说 ，，xx工具箱是存储工具和各种家庭杂物的容器，可用于生产，家庭，维修，钓鱼等各种用途，使用广泛。它分为移动型和固定型。移动性的工具箱也就是所谓的工具车。那么你知道吗?下面来学习一下吧。工具箱英语说法1：kit工具箱英语说法2：tool case工具箱英语说法3：tool cabinet工具箱的相关表达：优化工具箱Optimization Toolbox ; optimized kit ; optimized toolbox ; optimization tool box抽象窗口工具箱 AWT ; Abstract Window Toolkit ; Abstract Windowing Toolkit ; awt木匠工具箱 iHandy Carpenter ; iHandysoft lnc符号数学工具箱 Symbolic Math Toolbox ; Symbolic Math ; symbolic maths tools ; symbolic math toolbox磁盘工具箱 DiskToolbox财政金融工具箱 Financial Toolbox手机工具箱 QPtools ; Nktools ; BoxTool应用工具箱 USAT ; SIM Application Toolbox固件工具箱 ROM Toolbox工具箱的英语例句：1. A good toolbox is a handy thing to have in any house.任何一个家庭都应备有一个好的工具箱以便随时使用.2. He opened the box to put in the hammer.他打开工具箱把锤子放里.3. Put back the tools in the box.把工具放回工具箱.4. Unfortunately, hierarchical trees are one of the most inappropriately used controls in the toolbox.遗憾的是, 层次树也是工具箱中最容易被错误使用的控件之一.5. Perhaps he was carrying a portable
启动轴starting axle 启动齿轮starting gear 启动棘轮starting ratchet wheel 复位弹簧restoring, pull back spring 弹簧座spring seating 摩擦簧friction spring 推力垫圈thrust washer 轴挡圈axle bumper ring 下料filling 切断cut 滚齿机gear-hobbing machine 剪料机material-shearing machine 车床lathe 拉床broaching machine 垂直度verticality, vertical extent 平行度 parallelism同心度 homocentricity 位置度position 拉伤pulling damage 碰伤bumping damage 缺陷deficiency 严重缺陷severe deficiency 摩擦力friction 扭距twist 滑动glide 滚动roll 打滑skid 脱不开can’t seperate 不复位can’t restore 直径diameter M值= 跨棒距test rod span 公法线common normal line 弹性elasticity 频率特性frequency characteristic 误差error 响应response 定位allocation 机床夹具jig 动力学dynamic 运动学kinematic 静力学static 分析力学analyse mechanics 拉伸pulling 压缩hitting 机床machine tool 刀具cutter 摩擦friction 联结link 传动drive/transmission 轴shaft 剪切shear 扭转twist 弯曲应力bending stress 三相交流电three-phase AC 磁路magnetic circles 变压器transformer 异步电动机asynchronous motor 几何形状geometrical 精度precision 正弦形的sinusoid 交流电路AC circuit 机械加工余量machining allowance 变形力deforming force 变形deformation 电路circuit 半导体元件semiconductor element 拉孔broaching 装配assembling 加工machining 液压hydraulic pressure 切线tangent 机电一体化mechanotronics mechanical-electrical integration 稳定性stability 介质medium 液压驱动泵fluid clutch 液压泵hydraulic pump 阀门valve 失效invalidation 强度intensity 载荷load 应力stress 安全系数safty factor 可靠性reliability 螺纹thread 螺旋helix 键spline 销pin 滚动轴承rolling bearing 滑动轴承sliding bearing 弹簧spring 制动器arrester brake 十字结联轴节crosshead 联轴器coupling 链chain 皮带strap 精加工finish machining 粗加工rough machining 变速箱体gearbox casing 腐蚀rust 氧化oxidation 磨损wear 耐用度durability 机械制图 Mechanical drawing 投影projection 视图view 剖视图profile chart 标准件standard component 零件图part drawing 装配图assembly drawing 尺寸标注size marking 技术要求 technical requirements 刚度rigidity 内力internal force 位移displacement 截面section 疲劳极限fatigue limit 断裂fracture 塑性变形plastic distortion 脆性材料brittleness material 刚度准则rigidity criterion 垫圈washer 垫片spacer 直齿圆柱齿轮 straight toothed spur gear 斜齿圆柱齿轮 helical-spur gear 直齿锥齿轮 straight bevel gear 运动简图kinematic sketch 齿轮齿条pinion and rack 蜗杆蜗轮worm and worm gear 虚约束passive constraint 曲柄crank 摇杆racker 凸轮cams 反馈feedback 发生器generator 直流电源DC electrical source 门电路gate circuit 外圆磨削external grinding 内圆磨削internal grinding 平面磨削plane grinding 变速箱gearbox 离合器clutch 绞孔fraising 绞刀reamer
英文翻译 机械设计 一台完整机器的设计是一个复杂的过程。机械设计是一项创造性的工作。设计工程师不仅在工作上要有创造性，还必须在机械制图、运动学、工程材料、材料力学和机械制造工艺学等方面具有深厚的基础知识。 Machine Design The complete design of a machine is a complex process. The machine design is a creative work. Project engineer not only must have the creativity in the work, but also must in aspect and so on mechanical drawing, kinematics, engineerig material, materials mechanics and machine manufacture technology has the deep elementary knowledge. 任何产品在设计时第一步就是选择产品每个部分的构成材料。许多的材料被今天的设计师所使用。对产品的功能，它的外观、材料的成本、制造的成本作出必要的选择是十分重要的。对材料的特性必须事先作出仔细的评估。 One of the first steps in the design of any product is to select the material from which each part is to be made. Numerous materials are available to today's designers. The function of the product, its appearance, the cost of the material, and the cost of fabrication are important in making a selection. A careful evaluation of the properties of a. material must be made prior to any calculations. 仔细精确的计算是必要的，以确保设计的有效性。在任何失败的情况下，最好知道在最初设计中有有缺陷的部件。计算（图纸尺寸）检查是非常重要的。一个小数点的位置放错，就可以导致一个本可以完成的项目失败。设计工作的各个方面都应该检查和复查。 Careful calculations are necessary to ensure the validity of a design. In case of any part failures, it is desirable to know what was done in originally designing the defective components. The checking of calculations (and drawing dimensions) is of utmost importance. The misplacement of one decimal point can ruin an otherwise acceptable project. All aspects of design work should be checked and rechecked. 计算机是一种工具，它能够帮助机械设计师减轻繁琐的计算，并对现有数据提供进一步的分析。互动系统基于计算机的能力，已经使计算机辅助设计（CAD）和计算机辅助制造（CAM）成为了可能。心理学家经常谈论如何使人们适应他们所操作的机器。设计人员的基本职责是努力使机器来适应人们。这并不是一项容易的工作，因为实际上并不存在着一个对所有人来说都是最优的操作范围和操作
2、应力和应变 在任何工程结构中独立的部件或构件将承受来自于部件的使用状况或工作的外部环境的外力作用。如果组件就处于平衡状态,由此而来的各种外力将会为零,但尽管如此,它们共同作用部件的载荷易于使部件变形同时在材料里面产生相应的内力。 有很多不同负载可以应用于构件的方式。负荷根据相应时间的不同可分为: (a)静态负荷是一种在相对较短的时间内逐步达到平衡的应用载荷。 (b)持续负载是一种在很长一段时间为一个常数的载荷, 例如结构的重量。这种类型的载荷以相同的方式作为一个静态负荷; 然而,对一些材料与温度和压力的条件下,短时间的载荷和长时间的载荷抵抗失效的能力可能是不同的。 (c)冲击载荷是一种快速载荷(一种能量载荷)。振动通常导致一个冲击载荷, 一般平衡是不能建立的直到通过自然的阻尼力的作用使振动停止的时候。 (d)重复载荷是一种被应用和去除千万次的载荷。 (e)疲劳载荷或交变载荷是一种大小和设计随时间不断变化的载荷。 上面已经提到，作用于物体的外力与在材料里面产生的相应内力平衡。因此,如果一个杆受到一个均匀的拉伸和压缩，也就是说, 一个力,均匀分布于一截面,那么产生的内力也均匀分布并且可以说杆是受到一个均匀的正常应力,应力被定义为 应力==负载 P /压力 A, 因此根据载荷的性质应力是可以压缩或拉伸的,并被度量为牛顿每平方米或它的倍数。 如果一个杆受到轴向载荷，即是应力，那么杆的长度会改变。如果杆的初始长度L和改变量△L已知，产生的应力定义如下: 应力==改变长△L /初始长 L 因此应力是一个测量材料变形和无量纲的物理量 ,即它没有单位;它只是两个相同单位的物理量的比值。 一般来说,在实践中,在荷载作用下材料的延伸是非常小的, 测量的应力以*10-6的形式是方便的, 即微应变, 使用的符号也相应成为ue。 从某种意义上说，拉伸应力与应变被认为是正的。压缩应力与应变被认为是负的。因此负应力使长度减小。 当负载移除时，如果材料回复到初始的，无负载时的尺寸时，我们就说它是具有弹性的。一特定形式的适用于大范围的工程材料至少工程材料受载荷的大部分的弹性, 产生正比于负载的变形。由于载荷正比于载荷所产生的压力并且变形正比于应变, 这也说明,当材料是弹性的时候, 应力与应变成正比。因此胡克定律陈述, 应力正比于应变。 这定律服从于大部分铁合金在特定的范围内, 甚至以其合理的准确性可以假定适用于其他工程材料比如混凝土，木材，非铁合金。 当一个材料是弹性的时候，当载荷消除之后，任何负载所产生的变形可以完全恢复,没有永久的变形。