Investigation on the Thinning Problem of the Fuel Tank Part Made from Aluminum Alloy Sheet 5754-O under Deep Drawing Process

Deep drawing process is a common sheet metal forming process in motor vehicle manufacturing. There are three main defects in deep drawn parts, tearing, wrinkling, and thinning. When the thinning is difficult to detect by visual inspection. Therefore, this study aims to solving the thinning problem on a fuel tank part which made from aluminum alloy sheet AA5754-O 1.5 mm thick under cold working deep drawing process, while the upper limit of thinning that desired by the manufacturer is 20%.  Two influential parameters viz. blank holder force and initial size of blank, were investigated and optimized by using Finite Element Analysis (FEA) through PAM-STAMP simulation software with the validated material models consisting of Hill’s 1948 anisotropic yield criterion and linear combination of Swift-Voce hardening law, when mechanical parameters in both of models were implemented by the result from uniaxial tensile test. Terminally, the study results reveal that decreasing the pre-study blank holder pressure from hydraulic cushion and initial size of blank, were unable to decrease the maximum percentage of thinning on the part as lower than the desired limit.