CFRP平-折-平连接接头试验研究与数值模拟

针对碳纤维增强复合材料（CFRP）平-折-平（FJF）连接接头强度和失效问题进行了试验研究和数值模拟。基于商用有限元软件ABAQUS，建立了FJF连接接头强度预测模型，通过与试验结果进行对比，探究了此类接头在拉伸载荷工况下的失效形式和承载能力，同时分析了搭接长度对接头强度和失效模式的影响。结果表明，利用模型预测的接头承载能力与试验结果的误差均小于3.5%，具有较好的精度。不同搭接长度下，FJF混合连接接头相较于胶接连接接头和机械连接接头强度均有提升。接头的强度随着搭接长度的增大而增大，搭接长度增大到一定程度后趋于平缓。搭接长度较小时，FJF混合连接接头失效表现为胶层沿搭接区的断裂和孔边挤压失效；搭接长度较大时，失效模式转变为层合板孔边拉伸断裂和胶层扩展至孔边的断裂。 

Experimental study and numerical simulation on CFRP flat-joggle-flat joints

Both experimental tests and numerical simulation were implemented to investigate the strength and failure problem of carbon fiber reinforced plastics (CFRP) flat-joggle-flat (FJF) joints. Based on the commercial finite element analysis software ABAQUS, strength prediction models of the FJF joints were built. Compared with the test results, the failure modes and the carrying capacity of the joints were studied under the tensile load condition. Meanwhile, the effect of the lap length on the joint strength and failure modes was analyzed. The results show that the carrying capacity for each joint predicted by the model has the error value under 3.5%, which illustrates good accuracy with the test results. For different lap lengths, the strength of the FJF hybrid joint is higher than that of the bonded and bolted joint. The strength of each joint increases with the lap length, but tends to flatten when the lap length increases to a certain level. As the lap length is small, the failure of the FJF hybrid joint is manifested by the fracture of the adhesive layer along the lap zone and the bearing failure. For larger lap length, the failure modes are changed into the tensile fracture of the laminated plate near the hole and the fracture of the adhesive layer extending to the hole edge.