Maximum load P

A closed – linked chain is obtained by bending low-carbon steel rods (of 12 mm in diameter) into the shape (shown in the figure). It is used in different parts of the world with a temperature fluctuation between 30C and -50C. The fracture toughness of the steel is 160Mpam1/2 at 30C but 40 Mpam1/2 at -50C, while the yield strength is almost constant 800Mpa. A small crack with a depth of 3mm is found at the inner surface. Calculate the maximum load P that can be applied at an environmental temperature of 30 C and -50C with a safety of 2.5.Graph will be shown on the file uploaded Q3(A)