Question

1. Fluctuating loading. The cold-drawn AISI 1040 steel bar (S590 MPa, S 490 MPa) shown in the figure is subjected to the following different cyclic loading conditions. Estimate the fatigue factor of safety based on achieving infinite life (use Modified Goodman method) and the yielding factor of safety. If infinite life is not predicted, estimate the number of cycles to failure. The fatigue strength modification factor f 0.87. For Marin factors, only consider k, kb, and kc; assume k,-ke-k,-I 6-mm D 25 mm + 10 mm (a) A completely reversed axial load fluctuating between 10 kN in compression to 10 kN in tension. (Ans. n,- 9.31; n,-1.8) (b) A fluctuating axial load from 28 kN in compression and 32 kN in tension. (Ans. ny- 2.91; n 1.19)

PLEASE MAKE SURE THE ANSWERS MATCH THE ONES GIVEN BETWEEN PARENTHESES

Answer 1

Py h-A. 18-39 2 19b lo-52 + 15-s 50 215 1,33 MFos 33