《材料力学》也引进了多个版本的英文原版教材,但由于教育体制和教学模式的差异,一时还很难直接用于我国目前的课程教学。缩编和改编是把优秀原版教材引入双语教学的桥梁。我们在开展材料力学双语教学的过程中,针对本专业的特点,尝试在国外优秀教材基础上精选其主体内容并进行适当缩编的方式,取得了较好的效果。通过几年的教学实践我们体会到,缩编的原版教材有内容贴近教学和语言原汁原味等特点,适于教学。
近年来,国家教育部出台的一系列倡导高等院校开展双语教学、引进原版教材的政策,对于加快我国高等教育改革的步伐,培养具有国际竞争力的高水平技术人才,发挥了积极的促进作用。材料力学也引进了多个版本的英文原版教材,但由于教育体制和教学模式的差异,一时还很难直接用于我国目前的课程教学。缩编和改编是把优秀原版教材引入双语教学的桥梁。我们在开展材料力学双语教学的过程中,针对本专业的特点,尝试在国外优秀教材基础上精选其主体内容并进行适当缩编的方式,取得了较好的效果。通过几年的教学实践我们体会到,缩编的原版教材有内容贴近教学和语言原汁原味等特点,适于教学。
由Ferdinand P. Beer等编写的Mechanics of Materials(Fourth Edition in SI Units)采用以应力为铺路石,以构件变形为主线的体系,符合国内教学改革的主流方向。教材结构清晰、论述严谨、图文并茂,同时还附有少量计算题目。该教材将杆件设计概念贯穿全书,广泛采用三维插图,有助于揭示力学原理、贴近工程实际以及培养学生分析问题、解决问题的能力。书中每章都分别针对基本概念和原理设置多个“Examples and Sample Problems”和“Homework Problem Sets”,每章后面还设有“Chapter Review and Summary”、“Review Problems”和“Computer Problems”,具有突出“三基”,循序渐进,由简到繁的特色。教材中一些专题性的内容是独立的,便于删减。
经过认真对比研究,我们选择了该书作为基础进行缩编。缩编后的教材保留了原版教材的特色,同时结合国内双语教学的需要适当地删减了一些内容,如去掉了塑性变形(除轴向拉伸与压缩变形以外)等国内材料力学教材都不讲授或很少讲授的内容,精选了部分例题、习题讲解和习题等。
缩编工作由上海师范大学建筑工程学院工程力学部张燕主持。其中张燕改编第4章、第9章、第10章和全书的习题; 王红囡改编第5~8章和附录,并负责全书统稿工作; 彭丽改编第1~3章内容。特别感谢赵一鸣同学为教材录入和排版所做的大量工作,以及缩编教材的倡导人王增忠副院长对于本工作给予的大力支持。查珑珑老师也对本书作出了贡献。
本教材适合于机械类和土木类等专业的本科生70~90学时的材料力学双语教学,不足70学时应酌情删减。由于时间和编者的水平限制,书中难免疏误,敬请读者批评指正。
1
Introduction—Concept of Stress
1
1.1Introduction2
1.2Stresses in the Members of a Structure2
1.3Analysis and Design3
1.4Axial Loading; Normal Stress4
1.5Shearing Stress7
1.6Bearing Stress in Connections9
1.7Application to the Analysis and Design of Simple Structures9
Problems 1.112
1.8Stress on an Oblique Plane under Axial Loading14
1.9Stress under General Loading Conditions; Components of Stress15
1.10Design Considerations18
Problems 1.222
Review and Summary for Chapter 124
Review Problems26
Computer Problems27
2
Stress and Strain—Axial Loading
29
2.1Introduction30
2.2Normal Strain under Axial Loading31
2.3StressStrain Diagram32
2.4Hooke’s Law; Modulus of Elasticity37
2.5Elastic versus Plastic Behavior of a Material38
2.6Repeated Loadings; Fatigue40
2.7Deformations of Members under Axial Loading42
Problems 2.143
2.8Statically Indeterminate Problems45
Problems 2.247
2.9Poissons Ratio48
2.10Multiaxial Loading; Generalized Hookes Law48
2.11Shearing Strain50
Problems 2.351
2.12Stress and Strain Distribution under Axial Loading; SaintVenants Principle52
2.13Stress Concentrations54
Problems 2.456
Review and Summary for Chapter 256
Review Problems61
Computer Problems62
3
Torsion
63
3.1Introduction64
3.2Preliminary Discussion of the Stresses In a Shaft66
3.3Deformations in a Circular Shaft68
3.4Stresses in the Elastic Range71
Problems 3.174
3.5Angle of Twist in the Elastic Range77
3.6Statically Indeterminate Shafts79
Problems 3.281
3.7Design of Transmission Shafts84
3.8Stress Concentrations in Circular Shafts85
Problems 3.386
Review and Summary for Chapter 387
Review Problems89
Computer Problems91
4
Pure Bending
92
4.1Introduction93
4.2Symmetric Member in Pure Bending95
4.3Deformations in a Symmetric Member in Pure Bending96
4.4Stresses and Deformations in the Elastic Range99
4.5Deformations in a Transverse Cross Section103
Problems 4.1107
4.6Bending of Members Made of Several Materials109
4.7Stress Concentrations113
Problems 4.2117
4.8Eccentric Axial Loading in a Plane of Symmetry118
Problems 4.3122
4.9Unsymmetric Bending123
4.10General Case of Eccentric Axial Loading129
Problems 4.4132
Review and Summary for Chapter 4133
Review Problems137
Computer Problems138
5
Analysis and Design of Beams for Bending
139
5.1Introduction140
5.2Shear and BendingMoment Diagrams142
Problems 5.1148
5.3Relations among Load, Shear, and Bending Moment151
Problems 5.2156
5.4Design of Prismatic Beams for Bending157
Problems 5.3160
Review and Summary for Chapter 5162
Review Problems165
Computer Problems165
6
Shearing Stresses in Beams
166
6.1Introduction167
6.2Shear on the Horizontal Face of a Beam Element168
6.3Determination of the Shearing Stresses in a Beam171
6.4Shearing Stresses τxy in Common Types of Beams172
Problems 6.1174
Review and Summary for Chapter 6176
Review Problems177
Computer Problems178
7
Transformations of Stress and Strain
179
7.1Introduction180
7.2Transformation of Plane Stress181
7.3Principal Stresses: Maximum Shearing Stress183
Problems 7.1189
7.4Mohr’s Circle for Plane Stress190
Problems 7.2198
7.5General State of Stress198
7.6Application of Mohr’s Circle to the ThreeDimensional Analysis of Stress200
Problems 7.3203
Review and Summary for Chapter 7205
Review Problems207
Computer Problems208
8
Principal Stresses Under a Given Loading
209
8.1Introduction210
8.2Principal Stresses in a Beam211
8.3Design of Transmission Shafts214
Problems 8.1216
8.4Stresses under Combined Loadings218
Problems 8.2219
Review and Summary for Chapter 8222
Review Problems224
Computer Problems225
9
Deflection of Beams
226
9.1Introduction227
9.2Deformation of a Beam Under Transverse Loading228
9.3Equation of the Elastic Curve229
*9.4Direct Determination of the Elastic Curve from the Load Distribution234
9.5Statically Indeterminate Beams236
Problems 9.1241
*9.6Using Singularity Functions to Determine the Slope and Deflection of a Beam243
Problems 9.2247
9.7Method of Superposition247
9.8Application of Superposition to Statically Indeterminate Beams249
Problems 9.3254
Review and Summary for Chapter 9256
Review Problems260
Computer Problems261
10
Columns
262
10.1Introduction263
10.2Stability of Structures263
10.3Eulers Formula for PinEnded Columns266
10.4Extension of Eulers Formula to Columns with Other End Conditions269
Problems 10.1275
10.5Design of Columns Under a Centric Load277
Problems 10.2287
10.6Design of Columns under an Eccentric Load290
Problems 10.3295
Review and Summary for Chapter 10296
Review Problems297
Computer Problems298
Appendices
299
Appendix AMoments of Areas300
Appendix BTypical Properties of Selected Materials Used in Engineering310
Appendix CProperties of RolledSteel Shapes312
Appendix DBeam Deflections and Slopes318