Analysis of the Cup-Drawing Process

Abstract

An analysis has been developed for the study of the cup-drawing process which includes radial drawing over a die and stretch-forming over a punch. Theoretical results were obtained on a Pegasus computer. The analysis for radial drawing has been limited in this investigation to the case of drawing with a pressure blank-holder although similar analysis can also be made for the case of drawing with a clearance blank-holder. For the brass and mild steel used, the agreement between the theoretical and experimental results is generally satisfactory. In the analysis of stretch-forming over a punch head, two cases were considered: one for a 4-in diameter flat-headed punch with 1-in profile radius and the other for a 2-in diameter spherical-headed punch. The material used was brass. Theoretical strains based on simplified conditions in stretch-forming were obtained and compared with the experimental results. Agreement is good between the theoretical and experimental circumferential strains but the correlation between the thickness strains is unsatisfactory. For possible improvement in the theoretical results, a more exact analysis has been suggested.