【摘要】 应用多点模具对压成形铝合金整体壁板是一种新技术,如何预测和避免筋条的失稳和断裂是该技术能否用于实际生产的关键问题之一。针对铝合金壁板筋条的多点弯曲过程,提出了失稳和断裂的判定方法,应用有限元模拟和多点压弯试验进行了对比分析。结果表明,失稳和断裂判定方法能够预测筋条产生失稳和断裂的位置和时刻。基于多点模具形状调整快的特点,采用分道次成形的方式研究了压弯半径对筋条断裂和失稳的影响规律,确定了单筋条多点压弯时的极限曲率半径。模拟了复杂结构整体壁板在变路径加载条件下的失稳和断裂情况,优化了加载路径。更多还原

【Abstract】 The application of multi-point dies in the aluminum alloy integral panel forming is a novel forming method. However, how to predict and avoid the instability and fracture of the stiffeners has become a difficult problem in practical application. In this paper, the criterions for instability and fracture of the stiffeners in multi-point forming process were proposed. And the finite element simulation and multi-point bending test were carried out to make a comparison. The results show that the criterions proposed can predict the positions and moments when the instability or fracture occurs. Moreover, the changing of fracture and instability with different bending radius in step-by-step multi-point forming was investigated, and the forming limits of the stiffeners were also found out. The instability and fracture of integral panels with varying path forming were simulated, and the optimal loading path is selected.更多还原