重庆大学考研机械专业英语中文翻译大全

stress and strain 应力与应变

In any engineering structure工程结构 the individual components独立构件 or members will （be subjected to）受到，被附加 external forces外力 arising from由。。引起 the service conditions工作环境 or environment in which the component works.

在任何的工程结构中，每个零件，构件将会受到来自工作环境的外力的作用。

If the component or member is in equilibrium平衡, the resultant合力 of the external forces外力 will be zero but, nevertheless不然的话, they together place a load on the member which tends to deform使变形 that member and which must be reacted作用 by internal forces内力 set up within the material由材料提供.

如果这构件是处于平衡状态的话，外力的合力是为零。但是他们必须由材料提供的内力来平衡。++

There are a number of different ways in which load负载 can be applied作用to a member. Loads may be classified分类 with respect to time:

负载作用于构件有许多的形式。相对于时间可以将负载分类为： (a) A static静态 load负载 is a gradually逐渐 applied作

用 load for which equilibrium is reached in a relatively相对 short time.

静态负载是逐渐作用的可以在相对较短的时间内达到平衡的负载。

(b)A sustained load持续载荷 is a load that is constant维持不变 over a long period of很 time, such as the weight of a structure构件重力. This type of load is treated处理，对待 in the same manner as a static load静态载荷; However for some materials对一些材料， and conditions of temperature and stress, the resistance抵抗力 to failure may be different under short time loading and under long time loading.

持续载荷是可以维持很长时间不变的载荷。比如构件的重力。这种类型的载荷和静态载荷是同样的处理方法。但是对于某种材料，在某些特定的温度和外部压力的作用下，构件抵抗失效的能力是不同的。

(c) An impact冲击 load is a rapidly很快的迅速的 applied load (an energy load). Vibration震动 normally results from an impact load, and equilibrium平衡 is not established确定 until the vibration振动 is eliminated消除, usually by natural damping forces阻尼力.

冲击载荷是一种快速作用的载荷。振动常常是有冲击载荷引起。在振动被消除之前，平衡是很难稳定的。而消除振动的一半都是靠阻力。

(d) A repeated load重复载荷 is a load that is applied作用

and removed移动 many thousands of times.

持续作用很多次，移动很多次的载荷称为持续载荷。

(e) A fatigue or alternating load交变载荷 is a load whose magnitude and sign are changed with time.

狡辩载荷是大小和符号都在不断变化的载荷。

It has been noted above that external force applied to a body in equilibrium is reacted by internal forces set up within the material.

上述的外力作用于物体时将会被材料提供的内力抵消而达到平衡。

If, therefore因此, a bar棒子，零件 is subjected to作用 a uniform统一的，制服 tension拉伸 or compression压缩, i.e. 也就是说a force, which is uniformly applied across the cross-section截面, then the internal forces set up are also distributed分布 uniformly and the bar is said to be subjected to a uniform normal stress正应力, the stress being defined定义 as:

因此，如果零件受到统一的拉伸或者压缩，也就是说，力均匀的分布在截面上，此时内力也同样是均匀分布，此时我们就说哦这个构件受到了正应力的作用。这种应力定义为：

stress=press/area=P/A

Stress б may thus be compressive or tensile depending on

the nature of the load and will be measured衡量 in units单位 of newtons牛顿 per square meter每平方米 (N/m2)or multiples倍数 of this.

这个力是压力还是拉力由构件所受的载荷确定。同时，此力可以用牛顿每平方米或者它的倍数来衡量。

If a bar is subjected to an axial load轴向载荷, and hence因此 a stress, the bar will change in length. If the bar has an original length L and changes in length by an amount δL, the strain应变 produced产生的 is defined as follows:

如果构件受到轴向的载荷，此时构件的长度会发生变化。如果构件的本身长度是L，改变了&L则，产生的应变定义为：

strain=chang in lengyh/original length=&l/l

Strain is thus a measure度量 of the deformation变形 of the material and is non-dimensional无量纲的, i.e. it has no unit没有单位; it is simply a ratio比例，比率，比值 of two quantities数量，数值 with the same unit.

因此，应变是材料形变的度量，而且它是无量纲的。也就是说它没有单位。它只是两个有相同的单位的数值之间的比值。

Tensile stress张应力 and strain拉应力 are considered被认为是 positive正的 in sense在某种程度. Compressive压应力 stress and

strain are considered negative负的 in sense. Thus a negative strain produces a decrease in length.

张应力和拉应力在被定义为正的，而压应力被认为是负的。因此负的压应力造成长度的减少。

A material is said to be elastic有弹性的 if it returns to its original, unloaded dimensions大小 when load is removed.

如果材料在外力卸去的时候长度回复到了受力前的正常情况，我们就说这种材料有弹性。

A particular特别的 form形式 of elasticity弹性 which applies to a large range of engineering material工程材料, at least over part of their load range负载范围, produces deformations变形 which are proportional to成比例的 the loads producing them.

很多材料都有这种特性，至少在一定范围内，变形与负荷是成正比的。

Since loads are proportional to成比例 the stress they produce and deformations are proportional to the strains, this also implies意味着 that, whilst material are elastic, stress is proportional to strain. Hooke’s law胡克定律 therefore states that

负载可以产生成比例的应力，而应力又可以产生成比例的形变。也就意味着材料有弹性。用胡克定律表示

This law is obeyed服从 within certain limits by most ferrous alloys铁基合金 and it can even be assumed理论上 to apply to

些常用的钻头。

Twist Drill 麻花钻

The twist drill is the most common type of drill. It has two cutting edges and two helical flutes that continue over the length of the drill body. The drill also consists of a neck and a shank that can be either straight or tapered.

麻花钻是最常用的钻。在钻身上有两个切削刃和两个螺旋形排削槽。还包括一个颈和一个柄，他们既可以是锥形的也可以是直的。

carbide tipped drill硬质工具刀头钻

Most of drills are made of high-speed steel. However, for machining hard materials as well as for large volume production, carbide tipped drill are available. As shown in Fig.24.1, the carbide tips of suitable geometry适当的几何学 are clamped夹紧 to the end of the tool to act as the cutting edges.

大部分的钻是高速钢做的。然而当材料是硬质材料或者是大批量生产时，硬质工具刀头钻常常更加适合。如图所示，适当的形状的硬质钻被夹紧到工具的末端作为刀具。

Core Drills中心钻，扩孔钻 A core drill consists of the chamfer凹槽, body, neck, and shank. A core drill has flat end. The chamfer can have three or four cutting edges. Core drills are employed for enlarging放大 previously之前 made holes and not for originating holes. This type of drill is characterized by greater productivity, high

machining accuracy, and superior quality of the drilled surfaces

中心钻包括凹槽，钻身，颈部和柄部。中心钻是平头的。凹槽可以有三到四个切割刃。扩孔钻是用来扩大之前已有的孔，而不能自己钻原始孔。这类钻的特点是生产效率高，机器精度高，孔的表面质量好。

Other Types of Drilling Operations其他类型的钻

In addition to conventional drilling, there are other operations that are involved in the production of holes in the industrial practice. Following is a brief description of each of these operations.

除了传统的钻，在工场实际中还包括别的类型的生产孔的方法。以下是对其中一些的简介。

Boring 镗孔

Boring involves enlarging a hole that has already been drilled. It is similar to internal turning and can, therefore, be performed on a lathe. There are also some specialized machine tools for carrying out boring operations. Those include the vertical boring machine, the jig boring machine, and the horizontal boring machine.

钻孔包括扩大已有的孔，类似于车削，因此可以在车床上操作。还有其他的特殊的机器可以用来钻孔。包括：立式镗床，坐标镗床和水平镗床。

counterboring扩孔

Already existing holes in the parts can be further machined

by counterboring as shown in Fig.24.3(a). In the counterboring operation, the hole is enlarged with a flat bottom to provide a space for the bolt head螺栓头 or a nut螺母, so it would be entirely below the surface of the part.

如图所示已经存在的孔还可以进行锪孔操作。在这次锪孔操作中，这个孔被放大出一个平底来留出螺栓头或者是螺母的空间，这样他们才能完全没入工件。

Countersinking

As shown in Fig.24.3(b), countersinking is done to enable accommodating适合 the conical seat of a flathead screw平头螺栓 so that the screw does not appear above the surface of the part.

如图所示，这个操作是为了给平头螺栓创造一个位置，这样他就不会出现在表面了。

Spot facing 锪孔

Spot facing operation removes only a very small portion of material around the existing hole to be provide a flat surface square to the hole axis, as shown in Fig.24.3(c). This has to be done only in case where existing surface is not smooth and is usually performed on casting or forgings.

锪孔只会从已存在的孔的表面切除少量的材料，使得孔的表面变得光滑，而且提高了同轴度，如图所示，这种操作往往是在工件表面不平整或者是锻铸出来的孔时用。

Reaming铰孔

Reaming is an operation used to make an existing hole dimensionally在尺寸上 more accurate than can be obtained by drilling alone. As a result of a reaming operation, a hole has a very smooth surface. The cutting tool used in this operation is known as the reamer.

铰孔是为了使已存在的孔在尺寸上可以比锪孔得到的更加的准确。铰孔得到的工件表面会变得非常的光滑，所用的刀具就叫做铰刀。

Tapping攻丝

Tapping is the process of cutting internal threads内螺纹. The tool is called a tap.

攻丝的过程就是制作内螺纹，刀具是叫丝锥。

Drilling operations can be carried out by using either electric hand drills or drilling machines. The latter differ in shape and size. Nevertheless the tools always rotates around its own axis while the workpiece is kept firmly fixed. This is contrary to相反 the drilling operation on a lathe, where the workpiece is held in约束 and rotates旋转 with the chuck卡盘. Following is a survey of the commonly used types of drilling machines.

钻孔工序既可以用手提电钻也可以用机器电钻。后者的不同是在于形状和尺寸。但是，当工件固定的时候，刀具总是绕着他自己的轴转动。（工件固定而刀具旋转）这与车床的工作原理相反。车床是把工件约束固定住，然后旋转卡盘。以下是一些常用的钻床的介绍。

Bench-type drilling machines are general-purpose, small machine tools that are usually placed on benches. This type of drilling machine includes an electric motor电动机 as the source来源 of motion, which is transmitted传送 via pulleys由。滑轮 and belts皮带 to the spindle, where the tool is mounted. The feed is manually手动的 generated进行 by lowering a lever handle手柄, which is designed to lower (or raise) the spindle.主轴

工作台型的钻床是多功能的，小型的工件一般会用这个加工。这种钻床是电动作为动能的来源，能量由滑轮，皮带传送到轴上工件安装的轴上。进给是通过控制专门设计的手柄达到的。

The workpiece is mounted on the machine table, although a special vise虎钳 is sometimes used to hold the workpiece. The maximum height of a workpiece to be machined is limited by the maximum gap间隙 between the spindle and the machine table

工件被固定在机床的平台上，有时用虎钳固定。允许加工的工件的最大高度是由刀具到钻床平台的距离决定的。

Upright Drilling Machines 立式钻床

Depending upon the size, upright drilling machine tools can be used for light, medium, and even relatively heavy jobs. It is basically similar to bench-type machines, the main difference being a longer cylindrical column fixed to the base.

由于形状，立式钻床可以用于轻型的，中型的甚至是较大型的工

件。他与台式机床差不多，不同是长圆柱固定在底座上。

Along that column is an additional, sliding table for fixing the workpiece which can be locked in position at any desired height. The power required for this type is more than that for the bench-type drilling machines.

Radial Drill摇臂钻床 A radial drill is particularly suitable for drilling holes in large and heavy workpieces that are inconvenient to mount on the table of an upright drilling machine. A radial drilling machine has a main column, which is fixed to the base. The cantilever guide arm, which carries the drilling head spindle and tool, can be raised or lowered along the column and clamped at any desired position. The drill head slides along the arm and provides rotary motion and axial feed motion. Again, the cantilever guide arm can be swung, thus enabling the tool to be moved in all directions according to a cylindrical coordinate system.

摇臂钻床特别适合在又大又重的工件上钻孔

After lathes, milling machines are the most widely used for manufacturing applications. In milling, the workpiece is fed into a rotating milling cutter, which is a multi-edge tool as shown in Fig.28.1. Metal removal金属切削 is achieved through combining the rotary motion of the milling cutter and linear motion of the workpiece

simultaneously.

车之后铣床被最广泛用于制造应用。铣削加工工件旋转输入铣刀,如图所示是一个多刃刀具。旋转运动与直线运动相结合，实现金属的切削加工。

Each of the cutting edges of a milling cutter acts as an individual single-point cutter when it engages with the workpiece metal. Therefore, each of those cutting edges has appropriate rake and relief angles. Since only a few of the cutting edges are engaged with the workpiece at a time, heavy cuts can be taken without adversely affecting the tool life. In fact, the permissible cutting speeds and feeds for milling are three to four times higher than those for turning or drilling. Moreover, the quality of surfaces machined by milling is generally superior to the quality of surfaces machined by turning, shaping, or drilling.

每个切削刃铣刀与金属接触时是单点切削。因此，每一个刀刃具有适宜的斜度与后角。因为同时有不止一个刀刃与工件接触，所以重力切削也不会对刀具产生大的影响，影响其寿命。事实上,其允许切削速度和进料速度是车削和钻孔的三到四倍。此外,由铣削加工表面质量通常比钻孔，刨削和车削要佔优势。

The milling process is characterized by: 铣削过程的特征是:

(1)Interrupted cutting. 适合间断性切割

Each of the cutting edges removes material for only a part of the rotation of the milling cutter. As a result, the cutting edge has time to cool before it again removes material. Thus the milling operation is much cooler compared to the turning operation.

每个刀刃旋转一次只切除一小部分的材料，因此，切削刃在下次切除材料之前有足够的时间冷却。因此相对于车削加工，铣削加工的刀片温度更加低。

(2)Small size of chips.体积小 Though the size of the chips is small, in view of鉴于，由于 the multiple多重 cutting edges in contact a large amount of material is removed and as a result the component is generally completed in a single pass unlike the turning process which requires a large number of cuts for finishing.

虽然刀片的尺寸小，但是由于有多重切削刃与工件接触，有很大量的材料在仅仅是一次玩完整的过刀中被切下来。而不像车削那样，为了达到最终要求需要切很多次。

(3)Variation in chip thickness.碎片厚度的变化 This contributes to the non-steady不稳定 state状态 cyclic conditions循环条件 of varying cutting forces during the contact of the cutting edge with the chip thickness varying from zero to maximum size or vice versa反之亦然. This cyclic variation循环变化 of the force can excite激发 any of the natural frequencies固有频率 of the machine tool system and is

harmful to the tool life and surface roughness generated.

这是有利于那种不稳定状态循环条件 变化的切削力在切削刃与切削厚度之间的接触 从零变到最大或者反之亦然。这个循环变化的力量能够激发任何机床系统的固有频率并且这是有害于表面粗糙度和刀具寿命的。

As far as the directions of cutter rotation and workpiece feed are concerned, milling is performed by either of the following two methods.

至于刀具旋转方向以及材料进给方向的关系,铣削由以下二种情况。

Up milling (conventional milling). In up milling the cutting tool rotates in the opposite direction to the table movement, the chip starts as zero thickness and gradually increases to the maximum size as shown in Fig.28.2(a). This tends to lift the workpiece from the table. There is a possibility that the cutting tool will rub the workpiece before starting the removal. However, the machining process involves no impact loading冲击载荷, thus ensuring smoother operation of machine tool.

逆铣(传统的，惯用的铣)。铣削刀具与工作平面以相反方向运动，切削的厚度从零开始，逐步增加到的最大值,如图Fig.28.2(a)。这可能会把工件弄出工作平台。有可能，在切削开始之前刀具就与工件接触。然而，加工过程不包括冲击载荷，因此需要确保机器工具的平稳工作。

The initial rubbing最初的摩擦 of the cutting edge during the

start of the cut in up milling tends to dull the cutting edge and consequently因此 have a lower tool life. Also since the cutter tends to cut and slide alternatively, the quality of machined surface obtained by this method is not very high. Nevertheless, up milling is commonly used in industry, especially for rough cuts粗削.

在你洗开始的阶段的这种摩擦会弄顿刀刃因此这种刀的寿命会缩短。还有由于此时切割与打滑刀具要选其一，加工件的表面质量又得不到保证很高。然而，不过逆铣在生产中只要不是粗削都常用这个。

Down milling (climb milling). In down milling the cutting tool rotates in the same direction as that of the table movement, and the chip starts as maximum thickness and goes to zero thickness gradually as shown in Fig.28.2 (b). This results in a kind of impact影响, or sudden loading. Therefore, this method cannot be used unless the milling machine is equipped with a backlash eliminator on the table lead screw. The maximum depth of cut is achieved directly直接 as the cutter刀具 engages参与 with the workpiece and this gives a large force, which will have to be taken care of by a rigid严格 lead screw导螺杆 for table feeding工作台进给.

顺铣。铣削刀具与工作平面以相同方向运动，切削的厚度从最厚开始，逐步减少到的零。用这种方法会有突如其来的载荷。因此除非在在机床导螺杆上装了齿轮消除装置，不然这样不好。刀具与工件刚刚接触的时候就达到了最大切割深度，而有了最大的力。因此必须严

格遵循导螺杆调节进行工作进给。

The advantages of this method include higher quality of the machined surface and easier clamping of workpiece, since cutting forces act downward. Down milling also allows greater feeds per tooth and longer cutting life between regrinds than up milling. But, it cannot be used for machining castings or hot rolled steel, since the hard outer scale will damage the cutter.

这种方法的优点包括高质量的机械加工面还有工件更易夹持。因为切削力大小是下滑的。顺铣可以有更大的进给量和更长的寿命。但是不能用于铸件加工还有热轧钢。因为坚硬的表面会伤害刀刃。

本文来源：https://www.bwwdw.com/article/b1l3.html