A bar 1 m long is bent and then stress relieved. The radius of curvature to the

Question:

A bar 1 m long is bent and then stress relieved. The radius of curvature to the neutral axis is 0.50 m. The bar is 30 mm thick and is made of an elastic, perfectly plastic material with Y = 600 MPa and E = 200 GPa. Calculate the length to which this bar should be stretched so that, after unloading, it will become and remain straight.