Time-Efficient and Precise FEM/BEM Simulation of a Cold Forging Process Verified by Tool Load Determination

Abstract

Developing green processes establishes new possibilities for cold forging industry. Current technological developments require automotive parts with less mass, but higher material-efficiency. To achieve these goals, high-strength steels and complex geometries are used. The rising process forces lead to increased tool loads and subsequently elastic tool deformation resulting in early tool failure or dimensional deviations. A numerical determination of tool loads during process enables their reduction by a load-dependent design of the tool geometry. Aim of this work is a time-efficient and precise determination of tool loads considering the complete tool system using the example of a lateral extrusion process. By domain decomposition into Finite Element Method (FEM) and Boundary Element Method (BEM) domains and subsequently an integrated FEM/BEM simulation, a significant computation time reduction towards a conventional FEM model is achieved. Experiments of the examined lateral extrusion process provide data for the verification of the investigated process simulation models. In order to be able to validate the simulated elastic tool deformations, strain gauges are installed on the die insert and allow an experimental measurement of the elastic radial die strains. Additionally the simulated process force development and the final workpiece geometry of the simulation models are compared with experimental results.