The first has to do with displacement of molecules within the material, and the second has to do with stress and strain. Why exactly does springback occur? There are two reasons. Efficiently predicting and accounting for springback are critical, especially when working with profound-radius bends, as well as thick and high-strength material. The tensile strength and thickness of the material, type of tooling, and the type of bending all greatly influence springback. Overbending to the bending angle allows the desired bent angle to be attained when the part is released from pressure (see Figure 1). When fabricating on the press brake, an operator will overbend to the bending angle, which is angularly past the required bent angle, compensating for the springback.
Springback occurs when the material angularly tries to return to its original shape after being bent. To a press brake operator, a bending angle is different from a bent angle, and it all has to do with that ever-present forming variable: springback. So that the metal springs back to the desired bent angle. The bendingĪngle is the beginning angle to which the operator overbends Springback is ever-present in sheet metal forming.
