Multiple-Step Incremental Air-Bending Forming of High-Strength Sheet Metal Based on Simulation Analysis

Abstract

The multiple-step incremental air-bending forming of sheet metal is an important and flexible manufacturing process. It is suitable for sheet parts with complex, curved faces. Most research on incremental air-bending forming are mainly based on experiments and explain the process through macroscopic metal deformation. Based on Hill's yielding criterion and exponential strain hardening law as well as plane strain conditions, an analytical model and ABAQUS finite element model (FEM) are proposed in this article for investigating the incremental air-bending forming process. Firstly, the multiple-step incremental air-bending forming processes on different bending tool parameters are simulated with the FEM to analyze the influences of the tool parameters on formed shape, air-bending forming force, and warpage deformation of the workpiece. Then, the multiple-step incremental air-bending forming process of a semi-ellipse-shaped workpiece with 11, 535 mm × 574 mm × 453 mm is simulated with FEM established by the optimum tool parameters as well as the optimal process parameters. Manifested by the experiment for incremental air-bending forming of this workpiece, the numerical simulation method proposed yields satisfactory performance in tool parameters optimization and workpiece forming.

Keywords:

• Multiple-step air-bending machining
• Sheet metal incremental forming
• Simulation
• Springback
• Tool and process parameters optimization

ACKNOWLEDGMENTS

This work was supported by the National Nature Science Fund of People's Republic of China, under 50875093/E050802 and Innovation Fund by the SANY Heavy Industry Co. Ltd., Changsha, China.