Unformatted text preview: EML 3005: Mechanical Design
Nagaraj K. Arakere, MAE Dept, UF EML 3005: Mechanical Design Mechanical & Aerospace Engineering Department University of Florida Homework #2: 8 September, 2016 Due 15 September (Wed, Submit hardcopy in class) The support bracket shown below consists of a solid circular bar, fixed at one end, with an arm at the free end. A load F is applied at the offset end of the arm. The yield strength of the material is Sy = 130,000 psi. The strain at fracture is 15% in 2 inches. a) What is the critical point at which yielding will initiate first, if the load F is gradually increased? b) For a load F, clearly show the state of stress at points A, B, C and D. c) Find the load F at which yielding is initiated at the critical point, using Max Shear Stress Yield Theory and Distortion Energy Yield Theory. d) What is the factor of safety for yielding at the other 3 points at the support, when yielding is initiated at the critical point? Use MSS to calculate factor of safety. Draw these points on the yield surface for MSS. EML 3005: Mechanical Design
Nagaraj K. Arakere, MAE Dept, UF Problem 2 The end of a 1-‐inch diameter steel bar is welded to a solid, rigid horizontal plate. The bar extends up 10 inches (along the Z-‐axis) and then (with a gradual curved corner) extends 8 inches parallel to the plate (along the X-‐axis). The free end of the bar is subjected to a 700 pound force which is perpendicular to the end and 30 degrees from the horizontal downward (force acts in the Y-‐Z plane. See sketch). The yield stress for the material is 100,000 psi. a. Draw the 1-‐inch bar cross section (above the weld) in the X-‐Y plane and show the critical point where yielding will initiate. b. Find the principal normal stresses and the maximum shear stress at the critical point. c. Find the factor of safety for yielding based on Maximum shear stress theory d. Find the factor of safety for yielding based on Distortion energy theory ...
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- Spring '09
- MAE dept, Nagaraj K. Arakere, critical point