Quality Prediction and Die Design Optimization for Sheet Metal Stamping Using Monte Carlo Simulation and Inverse Finite Element Modeling

摘要

Sheet metal stamping is one of most commonly used manufacturing processes. However, although much research has been carried out, few can predict the product quality without expensive experiment tryout, not to mention the design optimization. This paper introduces a new method for quality evaluation and die design optimization using a combination of Monte Carlo simulation and inverse FEM. The use of Monte Carlo simulation for predicting quality has been applied in several manufacturing processes, such as assembly. However, because of the excessive computation load of FEM, it has not been used for stamping. Recently, the inverse method, also called the one-step method, is developed, which is very fast while its accuracy is acceptable. Based on a combination of Monte Carlo simulation and the inverse method, we studied the quality variation of drawing a square dish. In the study, the workpiece loading / unloading variations and blank holding force variations are modeled as the variation of blank holding force with uniform probability distribution. The effects of the lubrication (i.e., the friction) and workpiece material (including the thickness and the plastic deformation properties) are also included in the simulation. Based on the analysis of the simulation results, the critical design parameters are identified. Accordingly, die design optimization is carried out to minimize the variations.