Question

In designing a shaft for variable loads, the S.N. diagram can be drawn by:  

(a) Joining the S_ut at 0 cycles and S_e at 106 cycles by a straight line on an S.N. graph

(b) Joining the 0.9 S_ut at 1000 cycles and S_e at 106 cycles by a straight line on a log S — log N graph

(c) Joining the 0.9 S_ut at 1000 cycles and S_e at 106 cycles by a straight line on an S.N. graph

(d) Joining the S_ut at 1000 cycles and 0.9 S_e at 106 cycles by a straight line on a log S — log N graph