Optimum blank shape design by sensitivity analysis

A method of blank shape design based on sensitivity analysis for the non-circular deep drawing process has been proposed. By assuming the final deformation shape to be a drawn cup with a uniform trimming allowance at the flange, the corresponding initial blank which gives the final shape after deformation has been found. With the aid of a well-known dynamic explicit analysis code PAM-STAMP, shape sensitivity has been obtained. To obtain the shape sensitivity numerically, a couple of deformation processes have been analyzed. In order to validate this method, deep drawings of a square cup, a clover shaped cup and an L-shaped cup have been chosen as the examples. In every case converged results have been obtained only after a few times of modification. With the predicted optimal blank, both computer simulation and experiment are performed. Excellent agreement is noted between simulation and experiment in every case. Through the investigation, the proposed systematic method of optimal blank design is found to be very effective in the design of a deep drawing process.