On the Behavior of Cold-formed Members under Normal Stresses: Effects of the Cold-forming Residual Stresses.

A multilayer elastoplastic two-dimensional model of wide sheet bending such as by brake forming has been studied using von Mises and Tresca yield criteria. Residual stresses are created in the longitudinal as well as the hoop direction, thus reducing the proportional limit and consequently the effective modulus of elasticity at stresses below nominal yield. Acknowledging the beneficial effects of strain hardening, it seems prudent to consider the residual stresses due to cold forming in structural applications, particularly in cases of compressive loading.