Problem 2 A sector of a steel plate with endurance limit Se = 400 MPa, and ultimate strength Sut = 1000 MPa, has a stress state defining with the following cycle parameters calculated with von Mises criterion: = 130 MPa ση σα max-Mises max-Mises = = 400 MPa. Calculate the useful life in cycles according to Goodman criterion considering an equivalent cycle of completely inverted stress. Take n = 1 and work it in in sector of high cycle and finite life.

A large spherical tank (see figure) contains gas at a pressure of 420 psi. The tank is 45 ft in diameter and is constructed of high-strength steel having a yield stress in tension of 80 ksi. (a) Determine the required thickness (to the nearest 1/4 inch) of the wall of the tank if a factor of safety of 3,5 with respect to yielding is required. (b) If the tank wall thickness is 2.25 in., what is the maximum permissible internal pressure?

A W 360 x 79 steel beam is fixed at A. The beam has a length of 2.5 m and is subjected to a linearly varying distributed load with maximum intensity q0= 500 N/m on segment AB and a uniformly distributed load of intensity qQon segment EC. Calculate the state of plane stress at point D located 220 mm below the top of the beam and 0\3 m to the left of point B. Find the principal normal stresses and the maximum shear stress at D. Include the weight of the beam, See Table F-l(b), Appendix F, for beam properties.

Solve the preceding problem for a steel plate with x= 11,600 psi (tension). y= -5700 psi (compression), x = 450 x 10-6 (elongation), and y = -310 × 10-6 (shortening).

ou A bar of steel has the minimum properties S,- 276 MPa, S,-413 MPa, and Su= 551 MPa. The bar is subjected to a steady torsional stress (r m) of 103 MPa and an alternating bending stress (oa ) of 172 MPa. Find the factor of safety guarding against a static failure, and either the factor of safety guarding against a fatigue failure or the expected life of the part. For the fatigue analysis use: (a) Modified Goodman criterion. (b) Gerber criterion. (c) ASME-elliptic criterion note // assume the Kr and Ks equal 1

4. A bar of steel has minimum properties of Se= 40 kpsi, Sy = 60 kpsi, and Sut = 80 kpsi. The rotating bar is subjected to a steady torsional stress of 15 kpsi with a completely reversed bending stress of 25 kpsi. Find the factor of safety guarding against first-cycle yielding and either the factor of safety guarding against fatigue failure or the expected life of the part. For the fatigue analysis, use: 1) Goodman criterion 2) Gerber criterion

Consider the 2-D state of stress shown below. Using the provided scales graph the Mohr's Circle for the 2-D state of stress with "full' details Draw the Planes of Principal and Maximum Shear Stresses Provide "full" details and Use 3 Sig. Fig. in this problem Oy = 15 Ksi Tcw → S Txy= -5 ksi Ox = 10 Ksi Tyx = 5 Ksi 10 5 -20 -10 5 10 15 20 5 10 Tccw → S'

= A shaft of circular cross-section with diameter 100 mm is sub- jected to a bending moment of M = 10 kN.m, torque T = 30kN.m, and axial load F = 50 kN. Consider for the material of the shaft a yield strength of oy 750 MPa. Determine the design factor of safety using Tresca and von Mises Theories. Hint: find the point in the shaft that would be subjected to the largest stresses caused by the forces applied. Refer the the lecture. Example of Tresca with the inclusion of safety factor: 01 - 03 2 Where N is the safety factor. = бу 2N

Q6

Question 3 The A hollow shaft with an outside diameter of 150 mm and an inside diameter of 130 mm is subjected to an axial tension load of P-75kN and torque TB 16 kN.m and TC = 7 kN.m which act in the directions shown in figure Q3. This shaft is made of a material that has a yield stress of yield = 40MPa. Determine the principal stresses and the maximum shear stress acting at point H on the surface of the shaft and factor of safety. Figure Q3 Tc