Optimization of the loading path for the tube-hydroforming process

Abstract

In general, hydroforming optimization aims to make a desired shape of a plastically deformed structure under dynamic forces. The automotive industry has shown great interest in tube hydroforming, which is a metal-forming process. The forces from the hydraulic fluid are utilized to deform a tube. The internal pressures and the axial feedings (of the axial forces) determine the quality of the deformed product. In this research, an optimization process is employed to evaluate the appropriate external forces but defects are prevented. The equivalent static loads method for non-linear static response structural optimization is used for the optimization process because the tube-hydroforming process is analysed by non-linear dynamic response analysis. The equivalent static loads are the static loads that generate the same response field as that of non-linear dynamic analysis and are utilized as the loading conditions in linear static response optimization. A novel process is added to the original equivalent static loads method for non-linear static response structural optimization to address the objective function and the design variables for tube-hydroforming optimization. A new technique is proposed to use the external forces as the design variables in linear static response optimization. A few hydroforming examples are solved by using the newly proposed techniques.