材料力学试卷3.pdf
第 1 页 共 10 页 材材 料料 力力 学学 考考 试试 卷卷 课 程 名 称 考试学期 得分 适 用 专 业 48 学时 考 试 形 式 闭卷 考试时间长度 120 分钟 一、填空题（共一、填空题（共 7 7 小题小题，计，计 2020 分）分）1、图示桁架在给定荷载作用下的零力杆包括（）。For the given loading,determine the zero-force members in the truss shown.（3分）2、材料力学对杆件的受力和变形进行研究时所作的基本假设有（）、（）、（）和（）。Enumerate the basic hypotheses assumed in the study of mechanics of materials.（4 分）3、三种材料的应力-应变曲线如图所示，从图中可以看出：（）材料强度高，（）材料刚度大，（）材料塑性好。Based on the stress-strain curves for three material types shown,determine the one representing the highest strength limit,largest stiffness and best plastic performance,respectively.（3 分）密 封 线 学号 姓名 第 2 页 共 10 页 4、图示销钉受轴向拉力P作用，则销钉内的剪切应力等于（），支承面上的挤压应力为（）。Determine the shearing and bearing stress developed in the pin shown.（2 分）5、若将圆形截面杆的直径增加一倍，则杆的拉伸（压缩）刚度、扭转刚度和弯曲刚度分别变为原来的（）、（）和（）倍。How many times will the tension/compression,torsion and bending rigidity of a circular cross-sectional bar become,respectively,if its diameter is doubled.（3分）6、用挠曲线近似微分方程()E IwMx 求解挠曲线时，适用的坐标系有哪些？（）Determine the applicable coordinate system(s)of the bending deflection formula:()E IwMx .（2 分）第 3 页 共 10 页 (a)(b)(c)(d)7、圆形截面梁在横力弯曲状态下的弯曲切应力在（）位置取最大值，该值为截面平均切应力的（）倍。Determine the location of the largest bending shear stress for a circular cross-sectional beam under transverse loading.How many times of this stress becomes when compared with the cross-sectional average.（3 分）第 4 页 共 10 页 二、试求图示屋顶桁架中杆CE、DE和DF中的内力，并指明是拉伸还是压缩。A Pratt roof truss is loaded as shown.Determine the force in members CE,DE and DF.State whether each member is in tension or compression.（10 分）第 5 页 共 10 页 三、如图所示，杆 ABC 和 CDE 在 C 点铰接，并由四根连接杆 AG、BF、DI和 EH 支撑，试求图示荷载作用下这四根连接杆内的内力。Members ABC and CDE are pin-connected at C and supported by four links AG,BF,DI and EH.For the loading shown,determine the force in each link.（10 分）第 6 页 共 10 页 四、聚酯树脂的拉压应力应变曲线如右图所示，左图中的刚性杆 AC 由该材料制成的杆 AB（直径 40 mm）和 CD（直径 80 mm）共同支撑，试求当 P=80 kN时刚性杆 AC 的倾斜角。The stress-stain diagram for a polyester resin is given in the figure.If the rigid beam AC is supported by a strut AB and post CD made from this material,determine the angle of tilt of the beam when P=80 kN.The diameter of the strut is 40 mm and the diameter of the post is 80 mm.（10 分）第 7 页 共 10 页 五、一拉伸试件应力应变图的弹性部分如下图所示，已知试件测试前直径为 13 mm，标记长度为 50 mm，试求当轴向拉力 P=20 kN 时杆件的直径和标记长度，设试件材料的泊松系数为 0.4。The elastic portion of the stress-strain diagram for a steel alloy is shown in the figure.The specimen from which it was obtained had an original diameter of 13 mm and a gauge length of 50 mm.If a load of P=20 kN is applied to the specimen,determine its diameter and gauge length.Take Poissons ratio as 0.4.（10 分）第 8 页 共 10 页 六、图示钢轴直径 50 mm，试求轴中最大扭转切应力，并作图表示扭转角随截面位置的变化函数关系。设钢轴剪切模量为 75 GPa。The steel shaft has a diameter of 50 mm and is subjected to the distributed and concentrated loadings shown.Determine the absolute maximum shear stress in the shaft and plot a graph of the angle of twist of the shaft versus x.The shear modulus G=75 GPa.（12 分）第 9 页 共 10 页 七、试求图示T形梁的剪力图、弯矩图和最大弯曲正应力。设截面尺寸 a=180 mm。The beam is subjected to the loading shown.If its cross-sectional dimension a=180 mm,determine the diagrams of shearing forces and bending moments,and the absolute maximum bending normal stress developed in the beam.（13 分）第 10 页 共 10 页 八、试求图示外伸梁截面 D 的挠度和截面 A 的转角,设EI为常数。For the beam and loading shown,determine the deflection at section D and the slope at section A.EI is constant.（15 分）
