Influence of Yield Criteria in the Prediction of Strain Distribution and Residual Stress Distribution in Sheet Metal Formability Analysis for a Commercial Steel

Abstract

In this study, Hill 48 and Barlat 89 yield criteria are evaluated by simulating the Limiting Dome Height test of the Numisheet 96 benchmark problem [1] for a commercial D-grade steel and the results are validated with experimental data. Three strain modes, viz. biaxial, plane strain, and uniaxial strain modes, are used in the simulation studies. The yield criteria are evaluated based on the strain distribution in forming and residual stress distribution after springback. The results show that the Hill 48 and Barlat 89 yield criteria do not show a good match with predicted results of strain distribution in the plane strain mode. The difference between predicted results and experiments can be attributed to the combined influence of friction coefficient and draw bead boundary condition. The prediction of residual stress distribution differed considerably with the yield criteria. The residual stress predicted is validated for selected locations using X-ray diffraction techniques.

Keywords:

• Draw bead
• Friction
• Low-carbon D-grade steel
• Sheet metal forming
• Strain modes
• Yield criteria

ACKNOWLEDGMENTS

The authors thank Professor Narasimhan, Department of Metallurgical and Materials Engineering, IIT Mumbai, for allowing us to access forming test facilities of IIT Mumbai and Nilesh Birajdar, research associate, IIT Mumbai, for his assistance in forming experiments. The authors also thank Dr. G. Balachandran of Ashok Leyland Ltd. for his valuable comments on the manuscript and Dr. Madhusudhan Reddy of Defence Materials Research Laboratory for allowing us to access the X-ray diffractometer for residual stress measurements.