发布时间 : 星期一 文章土木工程专业英语课后答案更新完毕开始阅读
图6.1说明：结构要实现的功能、形式、材料、结构上的荷载、结构的性能以及结构分析模型之间的关系。
(3)At this point(此时此刻) we need to discuss some of the aspects of structural behavior indicated in Fig.6.1 and to explain their respective relationships to the form and material of the structure.
此时此刻，我们需要讨论图6.1中表示出来的结构性能的某些方面，并且解释结构的形式和材料之间各自的关系。
(4)Materials may be classified as elastic, plastic, or viscoelastic. 材料可分为弹性，塑性，或粘弹性。
(5)The deformations of viscoelastic materials depend on time and therefore load history, whereas the deformations of elastic and plastic materials do not.
粘弹性材料的变形取决于时间和先前的加载历史,然而弹塑性材料的变形却不是。
(6)Energy is generally lost if a system does not recover its initial shape after unloading owing either to plastic behavior of the material or to frication forces within or between parts of the structure .
如果一个结构体系在卸载之后不能恢复到原先的形状，则能量一般会丢失，原因是材料的塑性性能，或结构各部分内部或之间的摩擦力。 (7)All these behavioral aspects of the structure will have a significant influence on the nature of the analysis used in studying the structure. 所有结构的这些性能方面将对研究结构分析的本质产生重大影响。
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(8)In addition, in developing the analytical model it will be necessary to consider whether the structural material is homogeneous(均匀的) or nonhomogeneous and whether it is isotropic, orthotropic, or anisotropic
此外，在发展分析模型中，将有必要考虑结构材料是否是均匀的，或者是非均匀的，以及它是否是各向同性，正交异性，或各向异性。 (9)However, it is important to recognize at the outset(起初) that the concepts that will be presented can be extended to the solution of many other classes of structural problems, including those involving(涉及) dynamic response(动力响应), material and geometric nonlinearities, inelasticity, instability, and continuous systems. 然而，一开始就要认识到提出的概念可以延伸到许多其他各种类型的结构性问题的解决方法，这些问题包括涉及动力响应，材料和几何非线性，非弹性，失稳和连续的体系。
(10)Loads usually need be treated as dynamic only if they are periodic in nature or they are applied very suddenly.
只有荷载本质上是定期或者施加很突然时，则荷载通常需要被视为动态的。
5、Translate the following sentence into English.
（1）结构的分类有多种方法，普通观察者会首先根据它们各自的功能把结构分为房屋、桥梁、船舶、塔架等等。
Structures can be classified in a variety of way. The casual observer(临
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时观测人) might first consider classifying structures(把建筑分级) according to their respective functions(各自功能): buildings, bridges, ships, aircraft, towers, and so on.
（2）结构设计中，需要考虑的是结构的安全性、适用性和可行性。 In structural design, it is the need for a safe, serviceable, feasible. （3）如果结构对荷载的反应，比如一点的位移，与施加的荷载大小成正比，则结构为线性的。
A structure is linear if its response to loading, say displacement at a point, is directly proportional to the magnitude of the applied load. （4）各向同性材料的物理性能在任一点的所有方向是相同的。 The physical properties of homogeneous materials are the same at each point.
（5）结构的性能通常是很难清除描述的，因为结构的材料既不是线性或非线性的，也不是弹性或塑性的。
the picture of structural behavior is generally not so clear as that just painted. That is, materials are not either “linear” or “nonlinear” and “elastic” or “plastic”.
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