Assume that you are responsible for the design of a wide-plate tension member built from a structural aluminum. The member has a center-crack defect (2a) and can be subjected to various service conditions. Information on the aluminum is as follows:
E = 10 %u2022 10 6 psi.
yield stress = 40 ksi.
da/dN = 0.66 x 10-8(deltaK) 25
Determine the propagation fatigue life for the following design conditions:
(a) Stress range = 20 ksi (0 to tension)
2a 0 = 0.5 in.
Kic = 50 ksi(in^1/2)
(b) Stress range = 20 ksi (0 to tension)
2a 0 = 2.0 in.
KIC = 50 ksi(in^1/2)
(c) Stress range = 20 ksi (0 to tension)
2a 0 = 0.1 in.
Kic = 50 ksi(in^1/2).