The cantilevered bar in the figure is made from AISI 1020 CD

The cantilevered bar in the figure is made from AISI 1020 CD steel and is statically loaded with F_x = 320 lbf, F_y = 260 lbf, and F_z = -105 Ibf. The critical stress element at A experiences sigma_x, bend = 58.6 k psi, sigma_x, axial = 0.407 k psi and tau =15.9 k psi. Determine the minimum modified Goodman factor of safety for fatigue at point A, based on infinite life. The force F is applied as a repeated load (zero to maximum).

Solution

From the above given data modified goodman factor of safety can be calculated as follows

miminum modified goodman factor of safety = 3