纤维铺层方式对CFRP?铝合金单搭接胶接接头拉伸性能影响

为了分析异质材料胶接接头内部典型应力分布规律与刚度退化特点，探究不同铺层方式对异质材料单搭接胶接接头内部应力分布状态影响规律，开展试验和仿真相关研究。首先，制备不同铺层方式的CFRP（carbon fiber reinforce plastic）?铝合金单搭接胶接接头试验件，使用拉伸试验机进行拉伸试验，获得基本试验数据。其次，利用连续损伤模型、3D Hashin失效判据和Cohesive Zone Model研究异质材料胶接接头不同部位典型破坏特点。结果表明，随着复合材料板中0°铺层比例增加，胶接接头极限载荷呈现增加趋势，与之相反接头拉伸位移逐渐缩短。接头铺层方式与载荷方向共同影响胶接接头力学性能，当复合材料板内部各个方向纤维铺层较为均匀时，可以有效降低接头应力集中，载荷方向与铺层纤维方向一致时，可有效提高接头连接强度。复合材料板中0°铺层占比对接头的极限载荷和刚度退化（scalar stiffness degradation，SDEG）影响较大，0°占比越小接头承载能力越弱，接头刚度退化越复杂。 

Effect of fiber layup methods on tensile properties of CFRP-aluminum alloy single-lap adhesive joint

In order to analyze the typical stress distribution rules and stiffness degradation characteristics of dissimilar material adhesive joints，the effects of different layup methods on the internal stress distribution state of dissimilar material single?lap adhesive joints were studied，and then tests and simulations were carried out.First，the CFRP （carbon fiber reinforce plastic）?Al single?lap adhesive joint test pieces with different layup methods were prepared，the tensile testing machine was used to perform tensile tests，and the basic test data were obtained.Second，the continuous damage model，3D Hashin failure criterion and Cohesive Zone Model were used to study the typical failure characteristics of different parts of the dissimilar material transfer joint.The results showed that as the proportion of 0° layup in the composite plate increased，the ultimate load of the adhesive joint showed an increasing trend，on the contrary，the tensile displacement of the joint gradually decreased.The joint layup method and the load direction affected the mechanical properties of the adhesive joint.When the fibers in all directions inside the composite plate were relatively uniform，the stress concentration of the joint can be effectively reduced.When the load direction was consistent with the direction of the laminated fibers，the joint strength can be effectively improved.The proportion of 0° layer in the composite plate had a greater effect on the ultimate failure load and SDEG （scalar stiffness degradation） of joint.The smaller proportion of 0° indicated the weaker bearing capacity of the joint and the more complex SDEG of joint.