Numerical simulation and experimental validation of a multi-step deep drawing process

Abstract

This paper presents the numerical simulation ofan industrial multi-step deep drawing process. A largestrain finite element formulation including a hyperelasticelastoplastic constitutive model and a contact-friction lawis used to this end where the steel sheet material parametersconsidered in the analysis are previously derived through acharacterization procedure of its mechanical response. Thenumerical predictions of the final shape and thickness distributionof the blank are compared and discussed withavailable experimental values measured at the end of threesuccessive drawing steps. In addition, a plastic work-baseddamage index is used to assess failure occurrence duringthe process. The damage values computed at the end of thedrawing process are found to be lower than that correspondingto rupture in the tensile test, considered here asthe threshold of failure, confirming, as observed experimentally,that neither fracture nor necking is developed inthe blank during the whole drawing process. Finally, thepossibility to carry out a reduced two-step drawing process,obtained by merging the second and third steps ofthe three-step process, is precluded since the damage criterionpredicts in this case excessively large values thatindicate that failure may occur in specific zones of thesheet.