自冲铆接接头拉剪强度的数值模拟研究

Numerical Simulation of Lap-shear Strength of Self-piercing Riveting Joint

针对自冲铆接接头拉剪强度的数值模拟方法进行研究。对0.7mm低碳钢+0.7mm低碳钢同种材料自冲铆接接头,0.7mm低碳钢+2mm铝合金的异种材料自冲铆接接头的剪切拉伸过程建立有限元模型,并对其剪切拉伸过程及铆钉与板材的受力变形情况和破坏失效模式进行了模拟和分析。从数值模拟结果可以看出,钢-钢同种材料与钢-铝异种材料自冲铆接接头遵循不同的破坏模式:在钢-钢自冲铆接接头拉剪过程中,铆钉从接头处脱出从而造成接头失效;而钢-铝铆接接头失效则发生在母材上。对模拟结果进行了试验验证,结果表明,有限元模拟结果与试验结果吻合良好。因此,综合考虑了材料接触形式和接头形状的有限元模型能够很好地预测该类接头拉剪过程的破坏模式和拉剪强度。

The numerical simulation method for predicting the lap shear strength of self-piercing riveting（SPR） joint is studied.The finite element models of 0.7mm low carbon steel＋0.7mm low carbon steel similar material and 0.7mm low carbon steel＋2mm AA6061 dissimilar material SPR joints are established based on the experimental results.Then,considering the contact conditions between the different parts of the SPR joint,the lap shear processes of these SPR joints are simulated.It can be seen from the simulating results that the failure modes of the similar and dissimilar materials SPR joints are different： for the steel-steel similar material SPR joint,the rivet is pulled out from the joint while the failure occurs in the base metal for steel-Al dissimilar materials SPR joint.Finally,experiments of SPR joint＇s lap shear process are carried out to validate the simulating results.It is shown that the simulating results of SPR joint＇s shear strength have a good agreement with the experimental results.That suggests the developed FE model,considering the contact conditions of the materials and the joint＇s shape,can be used to predict the shear strength and failure mode of SPR joint.