CFRP/AA5083自冲铆接头成形性能及损伤机制

Forming property and damage mechanism of CFRP/AA5083 self-piercing riveting joint

选用CFRP和AA5083铝合金进行自冲铆接,探究铆钉嵌入CFRP上表面深度和采用带孔CFRP板材对接头的影响,以实现对复合材料/金属自冲铆接工艺的优化。基于接头的成形曲线和成形截面分析,研究了接头成形质量的影响因素;通过拉伸-剪切试验测试了接头的成形性能与失效行为;结合显微硬度分布特征研究了接头成形特征与失效行为的联系。结果表明:随着铆钉嵌入深度的增大,CFRP板材的压溃损伤持续加重,接头失效行为由铆钉拉脱失效变为CFRP基板撕裂失效,成形性能呈下降趋势;带孔CFRP板材的使用减轻了CFRP的铆接损伤,改善了铆钉的刺入和成形,铝合金板塑性变形区也具有更好的硬化效果,接头具有更优的成形质量和成形性能。

CFRP and AA5083 aluminum alloys were selected for self-piercing riveting,the influence of rivet embedment depth on CFRP upper surface and the use of CFRP sheet with holes on the joint was investigated to realize the optimization of the composites metal/self-piercing riveting process.Based on the analysis of formation curves and cross-section of joints,the influence factors of joint forming quality were studied.The tensile-shear tests were used to test the joint forming properties and failure behaviors.The microhardness distribution characteristics were used to study the relationship between joint forming characteristics and failure behavior.The results show that with the increase of rivet embedment depth,the crushing damage of CFRP sheet continues to increase,and the failure behavior of joints changes from rivet pull-out failure to CFRP substrate tearing failure,with decrease tendency of the forming property.The using of CFRP sheet with holes reduces the riveting damage of CFRP,improves the piercing and forming of rivets,and there is also better hardening effect in the plastic deformation area of aluminum alloy sheet.The joints have better forming quality and forming property.