Improvement of initial blank shape for intricate products using slip line field

Conventional methods were used for constructing the slip lines around the die opening. A curve was drawn in order to establish the periphery of the initial blank and calculate the distance between the beginning and the end points, using the constructed slip lines. This distance was defined as the error distance parameter “d” which indicated the errors in calculations. The effects of die opening shape and drawing depth on the error distance “d” were investigated. For eliminating such an error, a modified method for drawing periphery of the initial blank has been introduced and its effectiveness on the calculated results have been shown.