Analysis of bending effects in sheet forming operations

Abstract

Abstract The majority of work in numerical analyses of sheet metal forming operations is based on the simple membrane‐shell theory which neglects the effect of sheet bending. While useful information can be extracted from these analyses, especially for stretch‐dominated operations, the membrane theory is basically inadequate for analysing the draw‐type operations where sheet metal bends, slides and unbends over a draw radius. This paper presents axisymmetric and plane‐strain finite element analyses of stretch/draw of sheet metal over a die corner radius. Numerical solutions obtained from a total Lagrangian formulation of a finite‐strain thin shell theory are used to indicate the relative significance of including the bending effects in various simple forming operations. Comparisons of the calculated results with available experimental data are also given.