Radial clearance influence on strain and stress distribution of the polygonal shape deep-drawing operation

In the existing research, polygonal -shaped dies were manufactured based on the dimensions of the design. These dies were then assembled on the deep-drawing device to create polygonal cups (specifically heptagonal cups) for conducting experimental work tests. The process was achieved via a deep-drawing operation to create heptagonal cups with dimensions (diameter D = 40mm and height L = 31.5 mm). For both experimental work and finite element analysis, the cups of heptagonal shapes were formed from flat circular blanks of Low Carbon Steel (thickness to = 0.7 mm) and diameter D = 80mm. A commercial software program, ANSYS, was employed to perform this finite element analysis. The research aims to study the effect of different radial clearance (RC = 1.1to,1.2to, and 1.3to) between die and punch for heptagonal shape DD operations on the forming load, the height of the cup, thickness distribution, strain and stress distribution along the cup wall (side-wall and wall curvature). The analysis outcomes indicate that the maximum forming force was 51.250 kN with the wall curvature, the maximum effective strain was 0.8231, and the maximum stress was 676 MPa when the ( R C = 1.1to). Additionally, the squeezing process in the mug wall occurred with ( R C = 1.1to).