Make the life estimate of Ex. 10.6 by the strain-based method. Use properties for 2024-T351 aluminum as likely to be similar to those for the given 2024-T3 alloy. Then compare and briefly discuss the two calculations as to the life obtained, the nature of the input information required, and the complexity of the calculation.
Double-edge-notched plates of 2024-T3 aluminum alloy (kt = 2.15) have a nominal stress versus life relationship of the form of Eq. 10.31, where Sar is given by the Walker relationship, Eq. 10.29, with fitting constants A = 1530 MPa, B = −0.217, and γ = 0.733. Assume that these plates will be repeatedly subjected in engineering service to the nominal stress history shown in Fig. E10.6.