1、机械工程英语课后答案机械工程英语课后答案【篇一：机械制造专业英语 课后答案(部分)】ress and strain（应力与应变） 1the fundamental concepts 基本概念 cross section 横截面 the internal stresses produced in the bar 杆的内应力 continuous distribution of hydrostatic pressure 流体静压力 the tensile load 拉伸载荷 a uniform dis tribution over the cross section 在横截面均匀分布 arbitr
2、ary cross-sectional shape 任意截面形状 tensile stresses 拉应力 compressive stresses 压应力 a normal stress 正应力 through the centroid of the cross sectional area 通过横截面形心 the uniform stress condition 压力均匀分布 the stress distribution at the ends of the bar 杆末端应力分布 high localized stresses 高度应力集中 an axially loaded bar
3、轴向载荷杆件 a tensile strain 拉应变 an elongation or stretching of the material 材料拉伸 a compressive strain 压应变 the ratio of two lengths 两个长度的比值 purely statical and geometrical considerations 从纯静态以及几何角度考虑 1.that branch of scientific analysis which motions, times and forces is called mechanics and is made up o
4、f two parts, statics and dynamics. 研究位移、 时间和力运动乘力是科学分析法的一个分支， 被称作力学， 力学由两大部分组成， 静力学和动力学。 2.for example, ifthe force operating on a sleeve bearing becomes too high, it will squeeze out the oil film and cause metal-to-metal contact, overheating and rapid failure of the bearing. 例如：如果止推轴承上的作用力过大的话，会挤出油
5、膜，引起金属和金属之间的相互接触， 轴承将过热而迅速失效。 3.our intuitive concept of force includes such ideas as place of application, direction, and magnitude, and these are called the characteristics of a force. 力的直观概念包括力的作用点、大小、方向，这些被称为力的三要素。 4.all bodies are either elastic or plastic and will be deformed if acted upon by
6、forces. when the deformation of such bodies is small, they are frequently assumed to be rigid, i.e., incapable of deformation, in order to simplify the analysis. 所有的物体既可以是弹性的也可以是塑性的， 如果受到力的作用就产生变形。 当变形很小的 时候它们被假设成刚体，也就是不产生变形。 5.the rigid-body assumption cannot be used in internal stresses and strain
7、s due to the applied forces to be analyzed. thus we consider the body to be capable of deforming. 刚体假设不能应用于内应力和内应变的分析，所以在实际力的分析时，要考虑物体的形变。 6.if all the forces acting on a particle are balanced, the particle will either remain at rest or will continue to move in a straight line at a uniform velocity.
8、 如果作用在质点上所有的力是平衡的，质点将会保持静止或做做匀速直线运动。 2 1) the main manifestations of capacity主要的表现能力 2) the maximum unit load （ stress） 最大单位载荷（应力） 3）stress-strain diagram 应力应变图 4）the simple tensile test 简单的拉伸试验 5）the percentage elongation at rupture 断裂伸长率 6）the ends of tensile specimens 拉伸试样的两端 7）permanent deformat
9、ion 永久变形 8）the resulting load-displacement curve 由此产生的载荷位移曲线 9）a substantial yielding of the material 大量产生的物质 10）yield point 屈服点 11) the transition from elastic to plastic behavior 从弹性到塑性的过度 12）material property table 材料属性表 13）plastic deformation 塑性变形 14）a specified standard length of the specimen 指
10、定的标准式样长度 15）at the moment of rupture 此刻的破裂 16）short cylindrical specimens 短圆柱标本 17）ductile materials 韧性材料 18）high stress concentration 高应力集中 19）ultimate tensile strength 极限抗拉强度 20）strain hardening zone 应变硬化始尺寸 ai 和 li 的应力和应变称 为工程应力和工程应变。 5)ductile and brittle materials behave differently in compress
11、ion test as well. the compression test is conducted on short cylindrical specimens placed between parallel plates. 塑性和脆性材料在压缩试验中表现的特性是不相同的。 压缩试验是把短圆柱形试件放在两平行平板之间进行的 6）the compression test diagram for these materials retains.the qualitative features of the tension test diagram.the ultimate compressiv
12、e strength of a brittle of a brittle material is determined in the same way as in tension. 材料压缩试验图保持了拉伸试验图性能上的特征。 脆性材料的最大压缩强度与最大拉伸强度 得到的方法相同。 第三单元 virtually all machines contain shafts. the most common shape for shafts is circular and the cross section can be either solid or hollow (hollow shafts ca
13、n result in weight savings). 几乎所有的机器都有轴，最常用的外形是圆形的，横截面是空心的或实心的圆形截面（空心 轴可以减少重量） 。 a shaft must have adequate torsional strength to transmit torque and not be overstressed. it must also be torsionally still enough so that one mounted component does not deviate excessively from its【篇二：机械制造专业英语课后翻译答案】nt
14、ific analysis which motions, times and forces is called mechanics and is made up of two parts, statics and dynamics. 研究位移、时间和力运动乘力是科学分析法的一个分歧，被称作力学，力学由两大部 分组成，静力学和动力学。 for example, if the force operating on a sleeve bearing becomes too high, it will squeeze out the oil film and cause metal-to-metal
15、contact, overheating and rapid failure of the bearing. 例如：如果止推轴承上的作用力过大的话，会挤出油膜，引起金属和金属之间的相互接触，轴承将过热而迅速失效。 our intuitive concept of force includes such ideas as place of application, direction, and magnitude, and these are called the characteristics of a force. 力的直观概念包括力的作用点、大小、方向，这些被称为力的三要素。 all bo
16、dies are either elastic or plastic and will be deformed if acted upon by forces. when the deformation of such bodies is small, they are frequently assumed to be rigid, i.e., incapable of deformation, in order to simplify the analysis. 所有的物体既可以是弹性的也可以是塑性的，如果受到力的作用就产生变形。当变形很小的时候它们被假设成刚体，也就是不产生变形,以此来简化
17、分析。 the rigid-body assumption cannot be used in internal stresses and strains due to the applied forces to be analyzed. thus we consider the body to be capable of deforming. 刚体假设不能应用于内应力和内应变的分析，所以在实际力的分析时，要考虑物体的形变。 if all the forces acting on a particle are balanced, the particle will either remain
18、at rest or will continue to move in a straight line at a uniform velocity. 如果作用在质点上所有的力是平衡的，质点将会保持静止或做做匀速直线运动。 第二单元 材料的强度与塑性 a tensile test consists of slowly pulling a sample of material with a tensile load until it breaks. the ends of tensile specimens are usually enlarged to provide extra area fo
19、r grip-ping and to avoid having the sample break where it is being gripped. 拉伸试验包括慢慢加载拉伸载荷直到断裂。拉伸试件两端加粗为了提供装夹区域和避免试件断裂。 the usual manner of conducting the test is to deform the specimen at a constant speed. for example, in the universal testing machines, the motion between the fixed and moving cross
20、heads can be controlled at a constant speed. 通常进行试验的方法就是使试件以恒定速度发生变形。例如，在万能拉伸试验机上，固定端和移动的十字滑块之间的变形是以恒定速度进行的。 the load that must be applied to enforce this displacement rate varies as the test proceeds. this load f may be divided by the cross-sectional area a to obtain the stress in the specimen at a
21、ny time during the test. 随着实验的进行，用来产生位移的载荷是随位移的变化而变化。在实验中，载荷f除以横截面积a可以得到任意时刻点的应力。为工程应力和工程应变。 ductile and brittle materials behave differently in compression test as well. the compression test is conducted on short cylindrical specimens placed between parallel plates. 塑性和脆性材料在压缩试验中表现的特性是不相同的。压缩试验是把短圆
22、柱形试件放在两平行平板之间进行的。 the compression test diagram for these materials retains the qualitative features of the tension test diagram. the ultimate compressive strength of a brittle material is determined in the same way as in tension. 材料压缩试验图保持了拉伸试验图性能上的特征。脆性材料的最大压缩强度与最大拉伸强度得到的方法相同。 第三单元 轴设计 virtually al
23、l machines contain shafts. the most common shape for shafts is circular and the cross section can be either solid or hollow (hollow shafts can result in weight savings). 几乎所有的机器都有轴，最常用的外形是圆形的，横截面是空心的或实心的圆形截面（空心轴可以减少重量）。 a shaft must have adequate torsional strength to transmit torque and not be over
24、stressed. it must also be torsionally still enough so that one mounted component does not deviate excessively from its original angular position relative to a second component mounted on the same shaft. 一个轴必须有足够的扭转强度来传递扭矩而不会破坏，同样也必须有足够的扭转刚度，这样安装轴就不能过度偏离相对于安装在同一轴上第二个零件的原始位置。 shafts are mounted on bea
25、rings and transmit power through such devices as gears, pulleys, cams and clutches. these devices introduce forces which attempt to bend the shaft; hence, the shaft must be rigid enough to prevent overloading of the supporting bearings. 轴安装在轴承上通过齿轮，滑轮，凸轮和离合器这些装置传递力。这些装置可以产生使轴弯曲的力，所以轴必修有足够的刚性防止支撑轴承的过
26、载。 in addition, the shaft must be able to sustain a combination of bending and torsion and bending. 另外，轴必须能承载弯扭组合的载荷，因此，这样就必须考虑弯扭组合的等效载荷。 components such as gears and pulleys are mounted on shafts by means of key. the design of the key and the corresponding keyway in the shaft must be properly evalu
27、ated. 齿轮和滑轮构件是用键的方式连接在轴上的，键和对应的键槽的设计必须进行估算。 another important aspect of shaft design is the method of directly connecting one shaft to another. this is accomplished by devices such as rigid and flexible couplings. 轴设计的另一个重要方面是直接连接两轴，通过刚性和柔性的联轴器装置来实现。 第四单元 spur gears齿轮 pressure angles for spur gears
28、are usually 14.5 or 20 degrees, although other values can be used. meshing gears must have the same pressure angles.齿轮轮齿之间齿槽的形状是复杂的，并且随着齿的数目和模数变化而变化，因此大多数齿轮的加工方法是展成齿腹齿廓而不是齿形成形加工。 worm gears are used where high ratios are desired and where the shafts are nonintersecting and at right angles. 蜗杆蜗轮应用于传动
29、比大而且两轴不相交但相互垂直的情况下。 it has the great advantage that the cutting tool is a simple rack with ( nearly ) straight sided teeth which can easily be ground accurately. 这种方法有很大的优势，切削工具是一个简单的带有直齿边的齿条 modern shapers cutting car gears can run at 2000 cutting per minute. the shape of the cutter is roughly the
30、same as an involute gear but the tips of the teeth are rounded. 现代切削汽车的成型器齿轮转速可达每分钟2000转，齿刀形状与渐开线大致相同，但齿顶是圆形的。 bevel gears are often used when two shafts are at right angles to each other and their centerline extensions intersect; however, some bevel gears are at angles other than 90 degrees. 圆锥齿轮一般
31、应用于相互垂直的两轴或两个中心线延长线的相交轴中，也可用于不垂直的两轴中。 第五单元cams 凸轮 the purpose of any cam is to produce a displacement of its follower; a secondary follower is often used to produce additional displacement in another location. 使用凸轮的目的是使从动件产生位移，次级从动件在另一位置产生附加运动。 the relative vertical position of point a with respect
32、to b needs to be raised if the reaction value at b is excessive. 如果b点的作用力过大，a点相对b点的相对垂直位置必须被提高。 in general, the follower is considered to be the part that comes in contact with the cam profile. however, when a secondary follower is used, the motion of the secondary follower is dictated by that of the primary follower. 总的来说，从动件是与凸轮轮廓相接触的零件，然而，当用次级从动件时，次级从动件的运动就需通过主要从动件来实现。 the simplest type of follower is the reciprocating type that merely moves up and down ( or in and out ) with the rotation of the cam; the centerline can be either collinear with the cam center
