材料力学试卷：201306 Mechanics of__ materials_final exam_A

1、姓名 学号 学院 专业 座位号 ( 密 封 线 内 不 答 题 )密封线线_ _ 诚信应考,考试作弊将带来严重后果！ 华南理工大学期末考试Mechanics of Materials试卷A注意事项：1. 考前请将密封线内填写清楚； 2. 所有答案请直接答在试卷上(或答题纸上)； 3考试形式：闭卷； 4. 本试卷共六大题，满分100分，考试时间120分钟。ProblemIIIIIIIVVVITotal scorescoreGrading personI. Simple calculation problems（5 problems, 5 points each, total 25 points）

2、01. A circular solid steel rod of diameter D is embedded into the concrete wall shown. The ultimate shear stress between the concrete and the rod can reach tu and the ultimate tensile stress for the steel rod can reach su. Derive an equation to determine how far the steel rod must be imbedded into t

3、he wall (shown as x) so that the rod will not pull out of the wall, regardless of how much load P is placed on the rod?xP02. A block R of rubber is confined between plane parallel walls of a steel block S (see figure). A uniformly distributed pressure p0 is applied to the top of the rubber block by

4、a force F. Derive a formula for the lateral pressure p between the rubber and the steel. (Disregard friction between the rubber and the steel, and assume that the steel block is rigid when compared to the rubber).03. A circular bar of magnesium alloy is 750 mm long. The stress-strain diagram for the

5、 material is shown in the figure. The bar is loaded in tension to an elongation of 6.0 mm, and then the load is removed.(a) What is the permanent set of the bar?(b) If the bar is reloaded, what is the proportional limit?04. What must be the equation y =f (x) of the axis of the lightly curved beam AB

6、 (see figure) before the load is applied in order that the load P, moving along the bar, always stays at the same horizontal level? 05. An overhanging beam ABC supports a concentrated load P at the end of the overhang (see figure). Span AB has length L and the overhang has length a. Determine the st

7、rain energy of the beam.II. A rigid bar AB of length L = 1600 mm is hinged to a support at A and supported by two vertical wires attached at points C and D (see figure). Both wires have the same cross-sectional area (A = 16 mm2) and are made of the same material (modulus E = 200 GPa). The wire at C

8、has length h = 0.4 m and the wire at D has length twice that amount. The horizontal distances are c = 0.5 m and d= 1.2 m.(a) Determine the tensile stress C in the wires due to the load P= 970 N acting at end B of the bar.(b) Find the downward displacement B at end B of the bar.（15 points） III. The 6

9、0-mm-diameter solid shaft is made of A-36 steel and is subjected to the distributed and concentrated torsional loadings shown. Determine (a) the angle of twist at free end A. (b) The maximum shear stress in the shaft. The shear modulus G of A-36 is 75 GPa.（15 points）IV. A 700N diver jumps from a hei

10、ght of 0.6 m onto end A of a diving board having the uniform cross section shown. Assuming that the divers legs remain rigid and using E=12GPa for the board material, determine(a) the maximum deflection at point A, (b) Draw dynamic bending-moment diagram for this beam.（15 points）V. The steel pipe AB

11、 has a 102-mm outer diameter and a 6-mm wall thickness. Knowing that arm CD is rigidly attached to the pipe. If the allowable stress in the pipe is s =160MPa. (a) Determine the normal stresses and shear stresses at the critical point and show them on a sketch of a properly oriented element.(b) Check

12、 the strength of the pipe with the fourth strength theory. (15points)VI. A viewing platform in a wild-animal park (see Figure a) is supported by a row of aluminum pipe columns having length L=3.25 m and outer diameter d=100 mm. The bases of the columns are set in concrete footings and the tops of the columns are supported laterally by the platform. The columns are being designed to support compressive loads P =100 kN. Determine the minimum required thickness t of the col