In the figure shown, shaft A, made of AISI 1020 hot-rolled steel, is welded to a fixed support and is subjected to loading by equal and opposite forces F via shaft B.A theoretical stress-concentration factor Kt s of 1.6 is induced by the 1/8-in fillet. The length of shaft A from the fixed support to the connection at shaft B is 2 ft. The load F cycles from 150 to 500 lbf.

(a) For shaft A, find the factor of safety for infinite life using the modified Goodman fatigue failure criterion.

(b) Repeat part (a) using the Gerber fatigue failure  criterion.

Transcribed Image Text:

8 in dia in fillet Shaft A Shaft B