Full Factorial Design of Experiment Approach to Quantify the Effect of Forming Parameters on Wrinkling Effect of Deep Drawn Cylindrical Cups

Abstract

With the advancement of the manufacturing industry and the increase in competition, the need of quality has become an ever-growing challenge in metal forming industry. Deep drawing is a typical sheet metal forming process which is widely used to manufacture thin walled automotive panels, aircraft body panels and utensils. Blank holding force, drawing ratio, lubrication and die profile are few key process parameters that effect on the quality of the final product. Since the complicated interaction of these forming parameters, deep drawn parts are susceptible to various defects such as ironing, earing and thinning. Wrinkles are a common defect in sheet formed products. This study focuses on improving the quality of deep drawing products by minimizing the formation of wrinkles. The effect of Blank Holding Force (A), Blank Sheet Thickness (B) and Punch Force Applying Rate (C) were considered. Full Factorial Design of Experiments (DOE) conducted by simultaneously changing each parameter. Wrinkles were measured using surface roughness machine. Results shows that there is a significant interaction between Blank Sheet Thickness and Blank Holding Force at 5 % significance level. Results were validated by conducting several confirmation runs with optimum parameter settings.