Study of effect of load on springback in sheet metal bending

Abstract

for inertial effects in the FEM of sheet metal forming process. Papeleux and Ponthot 5 discussed numerically the effect of blank holder force, friction etc. on the forming response. Chou and Hung 6 carried out FEM of several springback reduction techniques such as over bending, stretching, arc bottoming, pinching die, spanking and movement (double bend) techniques, used in 'U' channel bending. Math and Grizelj 7 reported springback and residual stresses of bent plates designed for assembling spherical tanks made of steel using elastic-plastic incremental FE calculations. Esat et al. 8 carried out springback analysis of different aluminum sheets with different thicknesses and FEM results were compared with empirical ones. Lei et al. 9 analyzed the free bending and square cup deep drawing to predict the springback, stress distribution etc. for stainless steel with FEM.In this investigation, an elasto-plastic analysis of sheet metal bending process was carried out using experiments to predict the springback and substantiated with FEM. The main feature of this study is to investigate the influence of load on the springback pertaining to arc type sheet bending. The experimental data on aluminum, copper, brass and mild steel sheets were presented and results were compared with FEM ones, which shows a reasonable agreement. SHEET BENDING EXPERIMENTA standard 400 tonne hydraulic press was used to carry out the experiment of sheet metal bending process. It has two parallel platens of tungsten carbide with facilities for measuring loads, displacements as well as the speed of the platen. Figure 1 shows the setup of bending process with the ABSTRACT Springback remains a major concern in sheet metal bending in fabricating any final product within the permissible tolerance. Apart from the geometrical and material parameters, springback is significantly affected by the forming load also and the present study is focused on it. Sheet metal bending process involves large rotation and strain as well as large springback due to elastic recovery of the material. Therefore, a large deformation algorithm based Finite Element software was used to model a typical sheet metal bending process employed in manufacturing cylindrical structures. A Total-ElasticIncremental-Plastic (TEIP) algorithm has been incorporated in an in-house software to handle large deformation and the elastic recovery during the unloading process. In addition, experiments have been performed on aluminum, brass, copper and mild steel sheets and substantiated with the FEM analysis.

Parameter Optimization in the Thermo-mechanical V-Bending Process to Minimize Springback of Inconel 625 Alloy

“…Panthi et al [13] developed and employed an FEA algorithm, namely total-elastic-incremental-plastic (TE-IP) for V-bending of aluminum sheets and found friction to be the least influential parameter over springback. Thipprakamaset al [14] studied the phenomenon of springback and spring-go in the V-bending process for aluminum (A1100) using FEA.…”