Die closing force in low pressure tube hydroforming

Recently, low pressure tube hydroforming has emerged as a technology to reduce the weight of automotive body structures by allowing the implementation of advanced high strength steels and minimizing the number of process steps. In this study, a simplified analytical model based on a rigid, perfectly plastic material model was developed to determine the die closing force needed to form a simple geometry using the low pressure hydroforming process. The analytical solution developed was compared with experimental and numerical results; this demonstrated a reasonable accuracy of the model which will assist in the understanding of the basic principles governing the low pressure hydroforming process.