TOOLING MESH GENERATION TECHNIQUE FOR ITERATIVE FEM DIE SURFACE DESIGN ALGORITHM TO COMPENSATE FOR SPRINGBACK IN SHEETMETAL STAMPING

An iterative FEM algorithm has been recently developed to compensate f or springback in die surface design of sheetmetal stamping. In each it eration of this algorithm, a new tooling mesh needs to be generated ba sed on the part geometry after the so-called ''spring-forward'' deform ation. Presents a technique to generate such tooling mesh by means of a finite element calculation. After the spring-forward simulation, a v irtual forming model is constructed. The virtual die and virtual punch are made from the part mesh with material changed from deformable to rigid. The virtual workpiece is generated by copying the die mesh and changing rigid body material to deformable material. The virtual workp iece is placed in between the virtual punch and the virtual die and th en a FEM calculation is conducted to press the virtual workpiece into the shape of the virtual die. The needed new tooling mesh can then be easily obtained from the deformed virtual workpiece. The new tooling m esh generated by this technique has the same configuration as the orig inal tooling mesh and geometric features of the part design are preser ved so that the CAD engineers who receive the modified die surface geo metry in the form of FEM mesh can work on the files with ease.