(Solved): An elastoplastic material with strain hardening has the stressstrain relationship shown in the figu ...

An elastoplastic material with strain hardening has the stressstrain relationship shown in the figure below. The yield point corresponds to \( 600 \mathrm{MPa} \) stress and \( 0.003 \mathrm{~m} / \mathrm{m} \) strain. The failure point corresponds to \( 800 \mathrm{MPa} \) stress and \( 0.07 \mathrm{~m} / \mathrm{m} \) strain. What is the exact strain at a load of \( 400 \mathrm{MPa} \) ? If the material is loaded to a stress of \( 400 \mathrm{MPa} \) and then the load is removed, what is the permanent residual strain? What is the exact strain that corresponds to a stress of \( 700 \mathrm{MPa} \) ? If the material is loaded to a stress of \( 700 \mathrm{MPa} \) and then the load is removed, what is the permanent residual strain?