Characterization and modelling of multi-step drawing process for thick steel sheets

Naval structures are built by welding together large flat or formed parts made from thick steel sheets. Some of these parts are manufactured by using a cold multi-step drawing process. It relies on forming by plastic deformation, thereby modifying the mechanical state of the manufactured part. This study aims at developing a better understanding of the multi-step cold drawing process for thick steel plates through both experimental and numerical approaches to identify its impact on final mechanical state of the part. The part of interest in this study is a dished end plate which can be manufactured by a two-step drawing process. The first step is made with a punch and die of the same curvature on a circular steel sheet. During the second step, the sheet is pushed entirely through an open die in order to straighten its edges. The process is modelled using the Abaqus finite element software including a comparison between a 3D model and a 2D axisymmetric one. To validate the numerical approach, this process will be studied experimentally at the full scale and several experimental measurements (DIC surface strain, thickness, final geometry) will be compared with numerical simulation.