A FEM Model to Predict Pressure Loading Cycle for Hydroforming Processes 1999-01-0677
Tubular hydroforming is a novel process that has recently gained much attention due to its cost-effective application in the automotive industry. Hydroformed automotive parts have high strength to weight ratio and have good repeatability with high dimensional accuracy. At this time, there is little experience in modeling the hydroforming process to better understand its application and researchers have tried using stamping simulation software to analyze the process. Unlike conventional sheet stamping which is a displacement driven process, tubular hydroforming is a force driven process and its success is governed by the nature of internal pressurization. Hence, a new three-dimensional finite element model using a computationally efficient 6-noded shell element has been developed. A simple pressure prediction model has been developed and integrated into the formulation for effective control of the process. The major advantage of this new finite element model is that it can provide the required pressure loading cycle for hydroforming a specific configuration based on a user specified rate of deformation. The paper includes some details of the formulation and preliminary results.