【摘要】 目的揭示铝合金板材磁脉冲辅助弯曲成形对回弹的影响机理。方法基于两种磁脉冲辅助成形方案,采用数值模拟软件LS-DYNA,建立磁脉冲辅助U形弯曲的有限元模型。结果与准静态成形相比,磁脉冲辅助U形弯曲成形能减小板料圆角区的残余应力,方案Ⅰ板料圆角区等效塑性应变大于方案Ⅱ板料圆角区的等效塑性应变;电磁体积力能有效减小回弹,且放电能量越大,回弹角越小;磁脉冲辅助U形弯曲成形能减小板料的弹性应变能。结论相同放电电压下,方案Ⅰ的回弹控制效果好于方案Ⅱ的回弹控制效果。磁脉冲辅助U形弯曲减小回弹的主要原因是板料圆角区残余应力的减小和弹性应变能的降低。更多还原

【Abstract】 The paper aims to reveal influencing mechanism of electromagnetic assisted U-shaped bending on springback of aluminum alloy sheet. Based on two electromagnetic assisted U-shaped bending schemes, an finite element(FE) model was established the electromagnetic assisted U-shaped bending with the numerical simulation software LS-DYNA. Compared with the quasi-static one, electromagnetic assisted U-shaped bending could reduce the residual stress in fillet area of sheet. The effective plastic strain in the fillet area of scheme I was higher than that of scheme II. The electromagnetic body force could reduce the springback significantly; and the higher the discharge energy, the smaller the springback angle was. The elastic strain energy of the aluminum alloy sheet was also reduced by the electromagnetic assisted U-shaped bending. With the same discharge voltage, the springback control effect of scheme I is better than that of scheme II. The main mechanism of the reduced springback in the electromagnetic assisted U-shaped bending is the decrease of residual stress and the reduction of elastic strain energy in fillet area of sheet.更多还原