Problem

A tension member has a hole drilled at its center, similar to the member in Figure 14.16....

A tension member has a hole drilled at its center, similar to the member in Figure 14.16. The dimensions of the member are w = 20 mm perpendicular to the figure, D = 60 mm, and ρ = 5.0 mm. The member is subjected to a tension load that cycles between Pmin = 30.0 kN and Pmax. The member is made of 2024-T4 aluminum alloy, with properties E = 72.0 GPa, v = 0.33, σu = 470 MPa, Y = 330 MPa, and σam = 190 MPa (determined by testing a smooth specimen to N = 106 cycles).

a. Determine the magnitude of Pmax to produce general fatigue fracture of the member in 106 cycles (see Example 16.4). Assume that fracture occurs at the hole section.
b. Determine the maximum and minimum stresses at the edge of the hole, assuming that the stress concentration factor need be applied only to the alternating component of stress (see Example 16.4).

FIGURE 14.16