外文翻译-材料力学的分析与设计.doc

1、毕 业 设 计（论 文）外 文 参 考 资 料 及 译 文译文题目： 材料力学的分析与设计 学生姓名： 学 号： 专 业： 所在学院： 指导教师： 职 称： 20xx年 2月 27日说明：要求学生结合毕业设计（论文）课题参阅一篇以上的外文资料，并翻译至少一万印刷符（或译出3千汉字）以上的译文。译文原则上要求打印（如手写，一律用400字方格稿纸书写），连同学校提供的统一封面及英文原文装订，于毕业设计（论文）工作开始后2周内完成，作为成绩考核的一部分。OBJECTIVESThe main objective of a basic mechanics course should be to deve

2、lop in the engineering student the ability to analyze a given problem in a simple and logical manner and to apply to its solution a few fundamental and well-understood principles. This text is designed for the first course in mechanics of materialsor strength of materials offered to engineering stud

3、ents in the sophomore or junior year. The authors hope that it will help instructors achieve this goal in that particular course in the same way that their other texts may have helped them in statics and dynamics. GENERAL APPROACH In this text the study of the mechanics of materials is based on the

4、understanding of a few basic concepts and on the use of simplified models. This approach makes it possible to develop all the necessary formulas in a rational and logical manner, and to clearly indicate theconditions under which they can be safely applied to the analysis and Designation nonfactual r

5、estructurings and machine components.Design Concepts Are Discussed Throughout the Text When-ever Appropriate. A discussion of the application of the factor of safety to design can be found in Chap. 1, where the concepts of both allowable stress design and load and resistance factor design are presen

6、ted.A Careful Balance Between SI and U.S. Customary Units Is Consistently Maintained. Because it is essential that students be able to handle effectively both SI metric units and U.S. customary units, half the examples, sample problems, and problems to be assigned have been stated in SI units and ha

7、lf in U.S. customary units. Since a large number of problems are available, instructors can assign problems using each system of units in whatever proportion they find most desirable for their class.IntroductionThe main objective of the study of the mechanics of materials is to provide the future en

8、gineer with the means of analyzing and designing various machines and load-bearing structures.Both the analysis and the design of a given structure involve the determination of stresses and deformations. This first chapter is devoted to the concept of stress.Section 1.2 is devoted to a short review

9、of the basic methods of statics and to their application to the determination of the forces in the members of a simple structure consisting of pin-connected members.Section 1.3 will introduce you to the concept of stress in a member of a structure, and you will be shown how that stress can be determ

10、ined from the force in the member. After a short discussion of engineering analysis and design (Sec. 1.4), you will consider successively the normal stresses in a member under axial loading (Sec. 1.5), the shearing stresses caused by the application of equal and opposite transverse forces (Sec. 1.6)

11、, and the bearing stresses created by bolts and pins in the members they connect (Sec. 1.7). These various concepts will be applied in Sec. 1.8 to the determination of the stresses in the members1.2A SHORT REVIEW OF THE METHODS OF STATICSIn this section you will review the basic methods of statics w

12、hile determining the forces in the members of a simple structure.Consider the structure shown in Fig. 1.1, which was designed to support a 30-kN load. It consists of a boom AB with a 30 3 50-mm rectangular cross section and of a rod BC with a 20-mm-diameter circular cross section. The boom and the r

13、od are connected by a pin at B and are supported by pins and brackets at A and C, respectively. Our first step should be to draw a free-body diagram of the structure by detaching it from its supports at A and C, and showing the reactions that these supports exert on the structure (Fig. 1.2). Note th

14、at the sketch of the structure has been simplified by omitting all unnecessary details. Many of you may have recognized at this point that AB and BC are two-force members. For those of you who have not, we will pursue our analysis, ignoring that fact and assuming that the directions of the reactions

15、 at A and C are unknown. Each of these reactions, therefore, will be represented by two components, Ax and Ay at A, and Cx and Cy at C. We write the following three equilibrium equations:We have found two of the four unknowns, but cannot determine the other two from these equations, and no additional independent equation can be obtained from the free-body diagram of the structure. We must now dismember the structure. Considering the free-body diagram of the boom AB (Fi