Factors Affecting on Residual Stresses & Springback in Sheet Metal Bending: A Review

In sheet metal bending, the springback phenomenon leads to undesired effects on the geometry and dimensions of the formed parts. One of the main causes that lead and influence the intensity of this instability phenomenon is the state of residual stresses generated by the bending process in the deformed material. To establish an interaction between springback and distribution of stresses it must be known the law of variation of their parameters, their factors of influence and their causes. The magnitude of residual stresses significantly affect the load carrying capacity and the fatigue strength of the formed member, so residual stresses distribution is essential to be find out. This paper reviews the various parameters affecting on residual stress & spring back such as punch angle, sheet thickness, punch tip radius, punch height, bending force, clearance between punch and die, sheet anisotropy etc.