超声冲击工艺参数对装甲铝合金焊接应力影响的有限元分析

Numerically simulating the effect of ultrasonic impact parameters on welding stress in 7A52 aluminum alloy

利用有限元软件ABAQUS,建立了7A52铝合金焊后超声冲击的有限元模型,预测不同超声冲击工艺参数对7A52铝合金残余应力大小和分布的影响.分析了超声冲击振幅、频率、静压力对焊接残余应力的影响规律.旨在探讨超声冲击工艺参数对7A52铝合金焊接残余应力改善的影响因素.结果表明,超声冲击振幅对残余应力场影响显著,频率次之,静压力对残余应力场影响最小;增大冲击振幅能够显著提高焊缝接头处的残余压应力值,且会增大压应力产生区域;增大超声冲击频率,会增加接头处残余压应力值,但增加的幅度有限;静压力对残余压力影响不明显.用所建模型计算得到的数值结果规律与实测的残余应力值基本一致.

A finite element model was established based on software ABAQUS for 7A52 aluminum alloy treated by ultrasonic impact after welding,in order to predict the size and distri-bution of residual stress on 7A52 aluminum alloy treated with different ultrasonic impact process parameters. The influence law of ultrasonic impact amplitude,frequency,static pressure on residual stress was analyzed. The simulation results show that the impact amplitude had significant effects on residual stress field.The second factor was the ultrasonic impact frequency. Static pressure had little influence on residual stress field. Increasing the impact amplitude could significantly improve the residual compressive stress in the welded joint and increase the area of compressive stress. Increasing ultrasonic frequency could increase the residual compressive stress values with a certain degree. The numerically calculated results of residual stresses using FEM basically agreed with the experimental results.