材料力学课堂教学软件（英文版）-范钦珊-chap.3 Tension or Compression of Rods.pptVIP

* * * TSINGHUA UNIVERSITY * TSINGHUA UNIVERSITY HIGHER EDUCATION PRESS BEIJING CHINA Fan’s Studio for Education and Teaching Prof.Fan’s Studio for Education and Teaching Back to main Menu (3) Guide to Solve Problems of Mechanics of Materials * Q.S.Fan Tsinghua University P.R.CHINA Mechanics of Materials Chapter 3 Stress and Deformation Analysis and Strength Design of Rods in Tension or Compression Back to the first page Back to main Menu Problem:Two sides of the upper portion of the straight rod shown in the figure are subjected to uniformly distributed loads whose direction parallel to the axis of rod, and the intensities of the loads is The First Kind of Exercise: Diagram of Normal Force and Calculation of Stresses Problem 1 Determine : 1.the normal stress in the cross section A, B, C 2.the maximum normal force in the cross section of rod and point out the point of application. Force FP = 20 kN is applied to the free end D. Knowing that the area of cross section of rod is A =2.0×10-4m2，l = 4m. The First Kind of Exercise: Diagram of Normal Force and Calculation of Stresses Problem 1 Determine the control section Determine the normal force in control section FNA FNC FNC Solution：1. Draw the diagram of normal force FNx/kN x Solution：1. Draw the diagram of normal force Finally we obtain： FNA = 60kN， FNB = 20 kN， FNE = 40 kN Create the FNx－x coordinate C 20 D 20 A 60 Draw the diagram of normal force Back to the first page The First Kind of Exercise: Diagram of Normal Force and Calculation of Stresses Problem 1 E 40 B 20 MPa MPa MPa Solution：2. Calculate the normal stress in the specified cross section. FNA = 60kN， FNB = 20 kN， FNE = 40 kN 3. The maximum normal stress The maximum normal stress is in the cross section A Back to the first page The First Kind of Exercise: Diagram of Normal Force and Calculation of Stresses Problem 1 Extensive problem α α 1. Crossing point B, draw an oblique section. Analyze that: Is ther