Piecewise linear approximation of nonlinear unloading-reloading behaviors using a multi-surface approach

A multi-surface approach is suggested to describe nonlinear and hysteretic unloading-reloading behaviors of sheet metals, adopting the concept of multiple yield surfaces in the Mróz model. This approach divides the elastic domain into many fields that have different values of elastic modulus, resulting in a piecewise linear, hysteretic unloading-reloading stress-strain curve. Because this approach simply divides the elastic domain, it can be...