Q1/Create an estimated (S-N) diagram and define its equation for an axial fully reversed loaded steel bar. Its cross section shown in figure (1). Determine the life in cycle that can be expected if the alternating stress is (127Mpa). The bar surface finch is hot rolled. The operating temperature is (506 Co) and (du-577 Mpa). 120 mm. 4

MECH.ENG. DESIGN 1 PART 2

Using the maximum-shear-stress (MSS) theory determine the factor of safety for a bar of AISI 1020 cold-drawn steel, see Table A-20) with the follwoing stresses: σx = 135 MPa, σy = -114 MPa

6 Please help. Provide Free Body Diagram, labeled with appropriate quantities to better understand. Also solve. Thank you.

Displacement with elemental stiffness method, the rest the same.

8. Refer to the figure below. Even though the cyclic loading accidentally caused the stresses to exceed the levels at point A slightly (as marked by the red arrow), the machine part may not break instantly according to the Modified Goodman fatigue failure criterion. True_ or False Alternating stress a Yield (Langer) line Soderberg line I A m Gerber line Midrange stress om Load line, slope r = Modified Goodman line Sy ASME-elliptic line Sut SalSm

A hollow aluminum cylinder made of 2014-T4 has an outside diameter of 2.50 in. and a wall thickness of 0.085 in. Its length is 14.5 in. What axial com- pressive force would cause the cylinder to shorten by 0.005 in.? What is the resulting stress in the 3-25. aluminum?

A part is loaded with a combination of bending, axial, and torsion such that the following stresses are created at a particular location: Bending - Completely reversed, with a maximum stress of 60 MPa Axial - Constant stress of 20 MPa Torsion - Repeated load, varying from 0 MPa to 50 MPa Assume the varying stresses are in phase with each other. The part contains a notch such that Kibending = 1.4, Kaxial = 1.1, and K. = 2.0. The material properties are Sy = 300 MPa and S, = 400 MPa. The completely adjusted endurance limit is found to be Se= 200 MPa. Find the factor of safety for fatigue based on infinite life. If the life is not infinite, estimate the number of cycles. Be sure to check for yielding. f,torsion

Answer is Not 43,-1 and 22.

Answer D, E, F