An equivalent model of jaw's boundary condition in numerical simulation of stretch bending for extrusions

Stretch bending is an important bending process of extrusion and widely used in automotive and aircraft industries. Effective application of this process demands sufficient knowledge of how different parameters influence the process and the final shape of the product. Numerical simulation is an effective approach of investigating these issues presently. However, an accurate description of blank's boundary condition is needed in order to simulate forming process accurately. An equivalent model is proposed to treat jaw's boundary condition in stretch bending process and stretch bending of rectangular hollow section aluminum extrusion is simulated by using this model. It is found that the results of tangential strain, cross-section distortion and springback agree with experiment in reasonable accuracy. So it is shown that the proposed equivalent model is feasible and lays the groundwork for future optimization of process parameters.