中级材料力学
2003-1
清华大学出版社
巴勃
594
《中级材料力学》是为理工科大学生和工程设计人员编写的材料力学、材料强度和应力分析教材,覆盖了该领域二级教程所需要的基本内容。书中通过许多日常生活和工程应用中的实际例子帮助读者建立关于力学概念的直观感性认识。告诉读者如何通过简单试验去验证理论概念,从而使他们能深入理解在工程设计公式中如何应用这些概念。广泛收集了大量基本的和高难度的习题,并注意与工程实际和设计经验紧密联系。《中级材料力学》积累了作者的教学经验,对一些通常认为枯燥而困难的问题给出了新颖而现代的处理方法。《中级材料力学》是本面向工程设计的力学教材,对从事应力分析和强度设计的科技工作者、讲授高等材料力学和应力分析课程的教师以及理工院校的高年级学生和研究生是一本很好的参考书。
CONTENTSChapter1IntroductionI1.1The Engineering Design Process11.1.1Economics of designcalculations21.2Design Optimization21.2.1Predicting the behavior of thecomponent41.2.2Approximate solutions51.3Relative Magnitude of Different Effects61.4Formulating and Solving Problems81.4.1Use of procedures91.4.2Inverse problems101.4.3Physical uniqueness and existencearguments111.5Review of Elementary Mechanics ofMaterials121.5.1Definition of stress components121.5.2Transformation of stresscomponents131.5.3Displacement and strain131.5.4Hookes law151.5.5Bending of beams171.5.6Torsion of circular bars181.6Summary18Further Reading19Problems19Chapter2Material Behavior and Failure252.1Transformation of Stresses272.1.1Review of two-dimensional results272.1.2Principal stresses in threedimensions302.2Failure Theories for Isotropic Materials362.2.1The failure surface372.2.2The shape of the failure envelope392.2.3Ductile failure (yielding)392.2.4 Brittle failure 502.3Cyclic Loading and Fatigue622.3.1Experimental data642.3.2Statistics and the size effect672.3.3Factors influencing the designstress722.3.4Effect of a superposed meanstress772.3.5Summary of the design process802.4Summary85Further Reading86Problems87Chapter3Energy Methods973.1Work Done on Loading and Unloading983.2Strain Energy1003.3Load-Displacement Relations1013.3.1Beams with continuously varying bending moments1043.3.2Axial loading and torsion1053.3.3More general expressions for strain energy1073.3.4Strain energy associated with shear forces in beams1073.4Potential Energy1073.5The Principle of Stationary Potential Energy1103.5.1Potential energy due to an external force1133.5.2Problems with several degrees of freedom1133.5.3Nonlinear problems1163.6The Rayleigh-Ritz Method1183.6.1Improving the accuracy1213.6.2Improving the back of the envelope approximation1233.7Castiglianos First Theorem1293.8Linear Elastic Systems1333.8.1Strain energy1333.8.2Bounds on the coefficients1363.8.3Use of the reciprocal theorem1373.9The Stiffness Matrix1383.9.1Structures consisting of beams1403.9.2Assembly of the stiffness matrix1433.10 Castiglianos Second Theorem1433.10.1 Use of the theorem1453.10.2 Dummy loads1473.10.3 Unit load method1503.10.4 Formal procedure for usingCastiglianos second theorem1513.10.5 Indeterminate problems1513.10.6 Three-dimensional problems1553.11 Summary157Further Reading158Problems158Chapter4Unsymmetrical Bending1774.1Stress Distribution in Bending1774.1.1Bending about one axis1774.1.2Generalized bending1804.1.3Force resultants1814.1.4Uncoupled problems1824.1.5Coupled problems1844.2Displacements of the Beam1874.3Second Moments of Area1904.3.1Finding the centroid1914.3.2The parallel axis theorem1924.3.3Thin-walled sections1964.4Further Properties of Second Moments1984.4.1Coordinate transformation1984.4.2Mohrs circle of second moments2004.4.3Solution of unsymmetrical bendingproblems in principal coordinates2034.4.4Design estimates for the behavior of unsymmetrical sections2064.4.5Errors due to misalignment2094.5Summary211Further Reading211Problems211Chapter5Nonlinear and Elastic-PlasticBending2255.1Kinematics of Bending2255.2Elastic-Plastic Constitutive Behavior2275.2.1Unloading and reloading2285.2.2Yield during reversed loading2295.2.3Elastic-perfectly plastic material2305.3Stress Fields in Nonlinear and Inelastic Bending2315.3.1Force and moment resultants2325.4Pure Bending about an Axis of Symmetry2335.4.1Symmetric problems forelastic-perfectly plastic materials2345.4.2Fully plastic moment and shapefactor2395.5Bending of a Symmetric Section about anOrthogonal Axis2405.5.1The fully plastic case2405.5.2Nonzero axial force2435.5.3The partially plastic solution2455.6Unsymmetrical Plastic Bending2485.7Unloading, Springback and ResidualStress2525.7.1Springback and residualcurvature2545.7.2Reloading and shakedown2575.8Limit Analysis in the Design of Beams2585.8.1Plastic hinges2595.8.2Indeterminate Problems2595.9Summary262Further Reading263Problems263Chapter6Shear and Torsion of Thin-WalledBeams2756.1Derivation of the Shear Stress Formula2766.1.1Choice of cut and direction of the shearstress2806.1.2Location and magnitude of themaximum shear stress2856.1.3Welds, rivets, and bolts2876.1.4Curved sections2896.2Shear Center2916.2.1Finding the shear center 2916.3Unsymmetrical Sections2986.3.1Shear stress for an unsymmetricalsection2986.3.2Determining the shear center 2986.4Closed Sections3006.4.1Determination of the shear stressdistribution3006.5Pure Torsion of Closed Thin-WalledSections3056.5.1Torsional stiffness3066.5.2Design considerations in torsion3096.6Finding the Shear Center for a Closed Section3106.6.1Twist due to a shear force3126.6.2Multicell sections3156.7Torsion of Thin-Walled Open Sections3166.7. lLoading of an open section away from its shear center3196.8Summary322Further Reading323Problems323Chapter7Beams on Elastic Foundations3397.1The Governing Equation3407.1.1Solution of the governing equation3417.2The Homogeneous Solution3427.2.1The semi-infinite beam3437.3Localized Nature of the Solution3477.4Concentrated Force on an Infinite Beam3497.4.1More general loading of the infinite beam3507.5The Particular Solution3517.5.1Uniform loading3527.5.2 Discontinuous loads3547.6Finite Beams3567.7Short Beams3587.8Summary361Further Reading361Problems362Chaptar8Membrane Stresses in AxisymmetricShells3698.1The Meridional Stress3708.1.1Choice of cut3738.2The Circumferential Stress3758.2.1The radii of curvature3778.2.2Sign conventions3798.3Self-Weight 3818.4Relative Magnitudes of Different Loads3848.5Strains and Displacements3868.5.1Discontinuities3878.6Summary389Further Reading390Problems390Chapter9Axisymmetric Bending of CylindricalShells4019.1Bending Stresses and Moments4019.2Deformation of the Shell4039.3Equilibrium of the Shell Element 4059.4The Governing Equation4069.4.1Solution strategy4089.5Localized Loading of the Shell4119.6Shell Transition Regions4129.6. lThe cylinder to cone transition4159.6.2Reinforcing rings4179.7Thermal Stresses4199.8The ASME Pressure Vessel Code4219.9Summary421Further Reading422Problems422Chapter10Thick-Walled Cylinders and Disks42910.1 Solution Method 42910.1.1 Stress components and the equilibrium condition43010.1.2 Strain, displacement, and compatibility43110.1.3 The elastic constitutive law43210.2 The Thin Circular Disk 43410.3 Cylindrical Pressure Vessels44010.4 Composite Cylinders, Limits and Fits44310.4.1 Solution procedure44410.4.2 Limits and fits44710.5 Plastic Deformation of Disks and Cylinders44810.5.1 First yield 44910.5.2 The fully plastic solution45010.5.3 Elastic-plastic problems45210.5.4 Other failure modes45510.5.5 Unloading and residual stresses45610.6 Summary457Further Reading458Problems458Chapter11Curved Beams46711.1 The Governing Equation46711.1.1 Rectangular and circular cross sections47011.1.2 The bending moment47111.1.3 Composite cross sections47411.1.4 Axial loading47411.2 Radial Stresses48011.3 Distortion of the Cross Section48211.4 Range of Application of the Theory48411.5 Summary485Further Reading485Problems485Chapter12Elastic Stability 49112.1 Uniform Beam in Compression49212.2 Effect of Initial Perturbations49712.2.1 Eigenfunction expansions50012.3 Effect of Lateral Load (Beam-Columns)50112.4 Indeterminate Problems50512.5 Suppressing Low-Order Modes50612.6 Beams on Elastic Foundations51012.6.1 Axisymmetric buckling of cylindrical shells51212.6.2 Whirling of shafts51312.7 Energy Methods51812.7.1 Energy methods in beam problems51912.7.2 The uniform beam in compression52012.7.3 Inhomogeneous problems52312.8 Quick Estimates for the Buckling Force52412.9 Summary526Further Reading526Problems527AppendixAThe Finite Element Method537A.1Approximation538A.I.1 The "best" approximation538A. 1.2 Choice of weight functions539A. 1.3 Discrete approximations541A.2Axial Loading545A.2.1The structural mechanics approach545A.2.2 Assembly of the global stiffness matrix547A.2.3 The nodal forces548A.2.4 The Rayleigh-Ritz approach549A.2.5 Direct evaluation of the matrix equation554A.3Solution of Differential Equations556A.4Finite Element Solutions for the Bending of Beams558A.4.1Nodal forces and moments562A.5Two- and Three-Dimensional Problems565A.6Computational Considerations566A.6.1Data storage considerations568A.7Use of the Finite Element Method in Design568A.8 Summary569Further Reading570Problems570AppendixBProperties of Areas577AppendixCStress Concentration Factors581AppendixDAnswers to Even-NumberedProblems585