Finite Element Method for the Analysis and Calibration of a Closed Loop Control Algorithm for Pressbrake Bending

Finite Element Analysis is shown to be a useful tool for the off-line calibration of a method for the real time control of a metal forming process. The identification of the material characteristics of a sheet being bent in a pressbrake is chosen as an example. Finite element analysis is used as a numerical experiment so that the accuracy of the simplified model needed for real time control can be assessed. The results can also suggest ways to improve the algorithm. In this example, the finite element analysis showed that the stress estimates are accurate, but the strain estimates need improvement either by the use of an empirical calibration factor or by the development of a more exact theory.