Finite element simulation of the tube hydroforming process—bending, preforming and hydroforming

This paper covers finite element simulations of the complete hydroforming process for the lower part of an A-pillar for a car. Simulations were carried out for the bending, preforming and hydroforming process using the MPP-version of the explicit code LS-DYNA. The study focuses on the development of a practical simulation procedure for the entire hydroforming process and how the bending and preforming operation influence the hydroforming result. The simulation results were also compared with experimental results with respect to the thickness distribution and the agreement proved to be good. The study shows the importance of the bending operation and that it is necessary to take it into account when performing hydroforming simulations. It also indicates that processes with multiple forming operations can be simulated with good accuracy.