Influence of Punch Velocity on Deformation Behavior in Deep Drawing of Aluminum Alloy

Abstract

Deep drawing is one of the important sheet-forming processes. Several process parameters are responsible for producing defect-free products of deep drawing. Out of those parameters, blank holder force is one of the widely studied process parameters, which significantly influence deep drawing. In the present study, the effect of velocity of the punch on deformation behavior of aluminum alloys is investigated. FEM simulation is conducted using commercially available software ABAQUS. It is found through FEM simulation that effective stress increases by nearly 56% with an increment in punch velocity from 150 to 350 mm/s. Besides this, equivalent plastic strain increases by five times on increment in punch velocity from 150 to 350 mm/s. von Mises stress and equivalent plastic strain found to be maximum at flange radii region (die corner) at all velocities of punch. Wrinkling is found to be absent during deformation (loading step) at all punch velocities. Wrinkling is obtained in deep drawn cups after unloading of the punch at all punch velocities except the lowest velocity of 150 mm/s. The phenomenon of wrinkling was found to be pronounced with increment in velocity of the punch after unloading of the punch. For prevention of wrinkling tendency during deep drawing, the velocity of punch should be less than 200 mm/s. Besides this, punch force, effective stress, and equivalent plastic strain found to increase nonlinearly due to increment in punch stroke. It is gathered through FEM simulation that wrinkling phenomenon increases with increment in punch velocity due to unloading of the punch during deep drawing.