– For axially loaded, unnotched specimens of titanium 6Al-4V, Table P9.5 gives fatigue test data for zero mean stress, and Table P9.33 gives additional data at various nonzero mean stresses. Combine the data from Tables P9.5 and P9.33 into a single data set and proceed as follows: (a) For the Goodman relationship, Eq. 9.15, calculate σar for each test, and plot these versus N f . Add the line from the fit to the zero mean stress data of Prob. 9.5, and comment on the success of the correlation.
(b, c, d) Proceed as in (a) for the mean stress relationships of (b) Morrow with σ˜ f B, (c) Morrow with σ f , and (d) SWT.