碳纤维增强树脂复合材料和铝合金温热自冲铆接工艺及接头力学性能

Joining process and mechanical properties of warm self-piercing riveting for carbon fiber reinforced polymer and aluminum alloy

为研究传统自冲铆(SPR)工艺连接碳纤维增强树脂复合材料(CFRP)和铝合金的损伤问题,制备三种典型铺层结构的自冲铆接头,研究铺层结构对接头表面宏观损伤形貌的影响。在不同测试温度下对CFRP进行力学试验,研究温度对CFRP力学性能及失效的影响。基于CFRP的温热力学性能,以减小接头损伤为目的,创新性提出了CFRP和铝合金的温热自冲铆接(WSPR)工艺,对比了两种铆接工艺获得接头中CFRP的损伤差异。制备CFRP和铝合金的WSPR接头,研究铺层角度对接头力学性能和失效过程的影响。研究表明:常温下铆接时,钉头附近区域易出现宏观裂纹缺陷,主要以平行于纤维方向的基体裂纹和垂直于纤维方向的纤维裂纹形式存在。在树脂基体的玻璃化转变温度下,CFRP在横向和剪切方向的延展性大幅度提高,导致WSPR接头的CFRP表面无宏观裂纹,同时减小了分层损伤面积。铺层角度影响接头的拉剪力学性能及失效过程,[0/90/0]_(s)铺层接头的力学性能最优。

To investigate the damage in self-piercing riveting(SPR)of carbon fiber reinforced polymer(CFRP)and aluminum alloy,three groups of SPR joints with typical ply angles were prepared,and the effects of ply angles on the macroscopic damage morphology of joints were studied.The effects of temperature on the mechanical properties and failure of CFRP were studied.Based on the thermal mechanical properties of CFRP,the warm self-piercing riveting(WSPR)process for CFRP and aluminum alloy was innovatively proposed for the purpose of reducing joint damage.The damage difference of CFRP in the joint obtained by two riveting processes was compared.The effect of ply angle on mechanical properties and failure process of WSPR joints in CFRP and aluminum alloy was investigated.The results show that macro-cracks tend to appear in the area near the rivet head at room riveting temperature,mainly in the form of matrix cracks parallel to the fiber direction and fiber cracks perpendicular to the fiber direction.At the glass transition temperature of the resin matrix,the ductility of CFRP in transverse and shear directions is greatly improved,resulting in no macro-cracks on the surface of CFRP sheet,and the delamination area is reduced in the WSPR joints.The ply angle affects the tensile-shear properties and failure process of the joint and the joint with[0/90/0]_(s) laminated structure has the optimist mechanical properties.