Finite element investigation on spring-back characteristics in sheet metal U-bending process

The most prominent feature of sheet metal forming process is an elastic recovery phenomenon during unloading which leads to spring-back and sidewall curl. Accordingly, it has been a crucial research subject for designing bending tools securing the dimension precision of products. However, the elastic recovery is not only associated with various tool parameters but also hard to predict accurately owing to the complex material deformation behavior. This paper aims at the numerical investigation on spring-back characteristics to the major process parameters. For this goal, we employ the updated Lagrangian thermo-elastoplastic finite element method to a plane-strain sheet metal U-bending process. A description of process formulation and finite element approximation is also presented.