A cast-steel C frame as shown in the figure has a rectangular cross section of 1.25 in by 2 in, with a 0.5-in-radius semicircular notch on both sides that forms midflank fluting as shown. Estimate A,...

A cast-steel C frame as shown in the figure has a rectangular cross section of 1.25 in by 2 in, with a 0.5-in-radius semicircular notch on both sides that forms midflank fluting as shown. Estimate A, rc , rn , and e, and for a load of 2000 lbf, estimate the inner and outer surface stresses at the throat C.

Subtracting A/rn of the circle from that of the rectangle yields ∫ dA/r for the C frame, and rn can then be evaluated