锻压力对铝合金点焊接头疲劳行为的影响

Effect of forging force on fatigue behavior of spot-welded joints of aluminium alloy

采用试验和有限元分析相结合的方法,考察了锻压力对铝合金电阻点焊接头中残余应力和接头疲劳行为的影响。结果表明,采用锻压力显著降低了熔核边缘外部热影响区中的残余应力,疲劳裂纹不再从热影响区中萌生,而是全部从熔核边缘处开始;残余应力的降低使得疲劳裂纹扩展的驱动力减小,接头的疲劳强度提高。

Using experimental and finite element analysis methods, the effects of electrode forging force are investigated on residual stress and fatigue behavior of spot welded aluminum alloy joints. Results show that forging force significantly reduces the residual stresses in the heat affected zone (HAZ); the fatigue cracks no longer initiate from the HAZ, while all cracks begin from the edge of nuggets. The mitigation of residual stress decreases the driving force for crack propagation, and leads to higher fatigue strength.