EXPERIMENTAL INVESTIGATION OF A SQUARE-CUP DEEP-DRAWING PROCESS

The analysis of the deep-drawing of a square cup has been carried out as part of an international bench-mark research program organised by the NUMISHEET organising committee. Aluminum and mild steel have been employed in the experiments. The draw-in of the flange has been determined for a punch travel equal to 15 and 40 mm. A grid consisting of squares was electrochemically etched on the surface of the blanks, and the principal strains were determined in three directions from grid measurements for the above-mentioned punch travels. The thickness strains were determined also from direct measurements of the thickness, the thickness strains so determined comparing favourably with the thickness strains determined from the grid measurements.