土木工程专业外语秦卫红主编1-7课后答案

ENGLISH WORDS 1 A total elongation of a bar carrying an axial force 带了轴力的杆件伸长量 2 A bar that has constant cross section throughout its length and a strait axis 一个全长等截面 的直轴 3 A uniform stretching 均匀拉伸 4 Units of force divided by area 单位面积上的力 5 A compressive stress 压应力 6 At right angles to its axis 垂直于轴杆 7 This condition will be realized if the axial force P acts through the centroid of the cross section as can be demonstrated y statics 这种情况将被认为 如果一个轴向力 P 作 用在横截面中心 那么它可以以静力学来解释 8 Also unless stated otherwise it is generally assumed that the weight of the object itself is neglected as was done when discussing the bar in Fig 1 1 同样 除非另有说明 这个 通常假设该物体的重力被忽略 对于在像图 讨论杆件的时候 9 By making an artificial cut through the bar at right angles to its axis we can isolate parts of the bar as a free body 人工的截开这个杆在垂直于轴向的方向上 我们能隔离出杆的 一部分为自由端 10 The concepts of stress and strain can be illustrated in an elementary way by considering the extension of prismatic bar 应力和应变能够用一种基本的方式来解释 考虑该柱形延伸 的杆件 11 Assuming that the stress has a uniform distribution over the cross section we can readily see that its resultant is equal to the intensity times the cross section area A of the bar 假 设在整个横截面上有着均匀分布的应力 我们能理解到它的结果等于强度 6 与横截面 面积 A 的乘积 12 When the bar is being stretched by the force P as shown in the figure the resulting stress is a tensile stress if the forces are reversed in direction causing the bar to be compressed they are called compressive stresses 当一个杆件被力 P 拉伸 我们可以看到在途中 这个结果应力为拉力 如果这个里方向相反 将造成这个敢见被压缩 这叫压应力 13 The critical load 临界荷载 14 The ultimate load 最终荷载 15 a modulus of elasticity 弹性模量 16 a factor of safety 安全因素 17 elastic buckling 弹性弯曲 18 initial crookedness 故有弯曲 19 the slenderness ratio 长细比 20 A diagram of the compressive stress in the column versus the slenderness ratio can now be plotted 一个图表关于有压力的柱体长细比能马上被绘制 21 For practical purpose it is sometimes sufficient to draw a straight line EB and to consider that it represents the critical stresses for medium length columns 对实际的目的而言 这个 有时候足以用画一条直线 EB 来考虑和代表临界应力关于中等柱体 22 At this stress the column fails either by a direct failure of the material or by bucking depending upon the slenderness ratio 对于这种应力的柱体被破坏不是直接压坏就是被 压弯 这取决于这根柱的长细比 23 This condition cannot be improved by using a higher strength material instead the critical stress can be raised by increasing the radius of gyration or by using a material with a higher modulus of elasticity 这种情况下不能被提高 用一更高的强度的材料 但是用一更高 回转半径的材料或者有更高弹性模量的材料能提高临界应力 24 The Euler formula for the critical load is inapplicable in some instances and gives values which are too high 欧拉公式的临界荷载有些情况不能应用 这回导致结果值太高 25 dead loads 静荷载 26 live loads 动荷载 27 the mean load 平均荷载 28 rational safety provisions 合理安全措施 29 random variable 随机变量 30 Safety requires that the strength of the structure be adequate for all loads which may foreseeably act on it 安全要求结构的强度对于预见的作用在这个上面的全部荷载是 充分的 31 Serviceability requires that deflections be adequately small that cracks if any be kept to tolerable limits that vibrations be minimized 适用性要求充分小的挠度 可以保持在 允许范围内的裂缝和尽量小的震动 32 Actual loads may differ from those assumed in the design 真实的荷载或许与假设中的设 计不相同 33 Actual loads may be distributed in a manner different from that assumed in the desigh 真 实的荷载分布情况或许与假设中涉及不相同 34 Dead loads are those which are consistent in magnitude and fixed in location throughout the lifetime of the structure 静荷载是一直在大小和位置都不变的作用在结构上 35 flat roof 平屋顶 36 pitched roof 人字形屋顶 37 upwind part of the roof 屋顶的逆风面 38 canopy roof 天蓬屋顶 39 windward part of the roof 屋顶的上风面 40 wind parallel with building facade 平行于建筑物正面的风 41 wind perpendicular to building facade 垂直于建筑物正面的风 42 When the undisturbed air flow approaches a building it is forced around and over the building 当没有干扰的气流接近一个建筑 它的力量是覆盖在建筑物的周围和上方 43 Pressure is marked by plus and suction is marked by minus in the following figures 压力 在下边的图表中为 引力为 44 For pitched roofs with a slope of between 15 and 30 suction as well as pressure may occur on the upwind part of the roof 对于坡度在 15 到 30 的人字坡而言 吸力和压力一 样或许作用在逆风屋顶 45 If this aspect was incorporated into the building traditions of areas prone to severe hurricanes the number of low rise structural failures in these areas could be reduced in the future 如这个方面综合考虑系统倾向于严重的飓风区域内不高的结构承载力破坏的数 量在这些区域在未来将减少 46 member performance 构件工作性能 47 rational safety provisions 合理安全储备 48 concrete cover distance 保护层厚度 49 random variable 随机变量 50 deep flexural members 深梁 51 Tension cracks in beams may be wide enough to be visually disturbing and in some cases may reduce the durability of the structure 梁中拉应力产生的裂缝足够宽看起来是烦人 的 在某些情况下或许会降低结构的耐久性 52 All reinforced concrete beams crack generally starting at loads well below service level and possibly even prior to loading due to restrained shrinkage 所有的钢筋混凝土梁的裂缝 通常开始于荷载低于服务水平 而且可能甚至在荷载作用前限制收缩 53 In early reinforced concrete designs questions of serviceability were dealt with indirectly by limiting the stresses in concrete and steel at service loads to the rather conservative values that had resulted in satisfactory performance 所有的钢筋混凝土设计中 适用性方面 的问题是被间接处理的 通过限制混凝土的应力和承受荷载的钢筋在保守之范围内来 导致完美的工作性能 54 In the discussion of the importance of a good bond between steel and concrete it was pointed out that if proper end anchorage is provided a beam will not fail prematurely even though the bond is destroyed along the entire span 在讨论一个好的连接在钢筋和混凝 土间的重要性 这是被指出的 如果正确的尾端锚固存在 一个梁不会被提早破坏 即使连接在整跨上被破坏了 亦如此 55 Experiments by Bromes and others have shown that both crack spacing and crack width are related to the concrete cover distance dc measured from the center of the bar to the face of the concrete Bromes 和其他人的实验表明 裂缝间距和裂缝宽度与保护层厚度有关 这个厚度是杆中心到混凝土表面的距离 56 Earthquake resistant structures 抗震结构 57 Post and resisting elements 立柱和梁的组合体 58 Lateral load resisting elements 抵抗侧应力的构件 59 Rigid diaphragms 刚性隔板 60 Structures with redundancy 超静定结构 61 Timber structures 木结构 62 The primary reason for this is that earthquake resistance of a structure is dependent to a large extent on its ability to absorb the energy input associated with ground motions 最基本的原因是一个结构的抗震很大程度上取决于相互依赖 他们吸收相关地震力的 能量的能力 63 The failure of relatively few members in the outer plane of the structure shown in Fig 6 2b may lead to total collapse whereas many more members must fail in the more redundant structure for it to collapse 很少构件的破坏在结构的表面像图 6 2b 将导致全部倒塌 然而在有很多约束的结构中 必须有更多的构件被破坏才会倒塌 64 Earthquake resistant structures also typically have floor and roof planes designed as rigid diaphragms capable of transmitting internal forces to lateral load resisting elements through beam like action 抗震结构也典型的有横面和屋顶被设计成刚性隔板 以此能够传递 内在力到抵抗侧向力的结构上 像梁一样的效果 65 Precast concrete structures however can be difficult to design for safety in earthquake zones because of the problems involved in achieving a continuous ductile structure 预知 的混凝土结构 然而难以设计在安全性上在地震多发地区 因为这些问题要涉及到连 续和延伸性的结构 66 Reinforced concrete 钢筋混凝土 67 Rolled steel 轧制刚材 68 Weldability 可焊性 69 Aggregate 骨料 70 Mortar 砂浆 71 Deformation 变形 72 The modern civil engineer needs to deal with a variety pf materials that are often integrated in the same structure such as steel and concrete or are used separately for construction