SELECTION OF MATERIAL FOR DEEP DRAWING OF A FUEL TANK AND ITS FINITE ELEMENT SIMULATION

Abstract

Deep drawing is a sheet metal forming process in which deformation forces are oriented in the plane of the sheet, and the surface pressures in the tool are generally lower than the yield stress of the sheet material. The limits of the sheet metal forming are determined by the occurrence of defects such as wrinkling and tearing on the blank which are the most frequent types of failure. The present work discusses the numerical investigations of deep drawing of a cold rolled draw quality steel and interstitial free steel blank of 0.8mm and 1.2mm thickness in to a shape of a fuel tank with varying blank holding forces. The tensile specimens are laser cut from a blank with known rolling direction as per ASTM E8M standard and are tested for tensile properties and anisotropy. These properties were used in the material model in FE analysis of the process using HYPERWORKS. It is observed numerically that optimum blank holder force is necessary to remove the wrinkling defects. Deep drawing parameters like percentage thinning and plastic strain along with respective forming limit diagrams have been obtained for individual cases and thus changes in these parameters with varying thickness and material is area of investigation for understanding deep drawing process over fuel tank.