Computational approach to analysis and design of hydroforming process for an automobile lower arm

Tubular hydroforming has attracted increased attention in the automotive industry recently. In this study, a professional finite element program for analysis and design of tube hydroforming processes has been developed, called HydroFORM-3D, which is based on a rigid-plastic model. The friction calculation between die and workpiece has been dealt with carefully by introducing a new scheme in three-dimensional surface integration. With the developed program, HydroFORM-3D, the hydroforming process for an automobile lower arm is analyzed and designed. The manufacturing process for a lower arm consists of tube bending, preforming, and final hydroforming. To accomplish successful hydroforming process design, thorough investigation on proper combination of process parameters such as internal hydraulic pressure, axial feeding, and tool geometry is required. This paper includes the study on the influences of the forming conditions on the hydroforming of a lower arm by using simulation to predict strain and tube shape during bending, preforming, and final hydroforming processes.