复合材料单搭胶结接头剪切试验及应力分析

Shear Tests and Stress Analysis of Single Lap Adhesive Joint of Composite Material

本研究通过单轴拉伸试验实现复合材料单搭胶结结构胶面剪切破坏测试,获得了结构的极限剪切强度,同时利用解析法和仿真模拟方法分析了胶层的剪切应力状态。研究结果表明:胶结件的破坏为胶层与搭接板间的脱粘破坏,无胶层内聚破坏;胶层横断面中部剪切应力值最低,胶结区端部产生应力集中,端部应力最大;胶层存在剪切应力的同时,也存在垂直于胶结面的拉应力,其破坏原因是剪应力和拉应力的综合影响结果;平均剪切应力计算结果显示:试验值、理论值和仿真结果分别为8.9 MPa、9.5 MPa和9.2 MPa,理论结果和仿真结果的应力变化趋势一致,理论解和仿真解与试验值的误差均在7%以内,理论分析和仿真模拟可实现胶结结构剪切应力的可靠预报。

The ultimate shear strength of single lap adhesive composite structure was obtained according to uniaxial tensile test, shear stress in the adhesive layer was calculated by theory analysis and numerical simulation analysis. The results show that： a brittle debonding was occurred between the adhesive layer and composite plate with no cohesive failure; the maximum shear stress occurs at the end of adhesive area. The trend of shear stress decreased at the middle of the sample and then increased to a maximum value. The failure was caused by the combination of the shear stress and tensile stress under the unidirectional tensile load. The average shear stress with experimental method, theoretical method and numerical method were 8.9MPa, 9.5MPa and 9.2MPa respectively. Stress variation trend under theoretical analysis was in agreement with numerical simulation results within a lower error band 7 %. The method combing experimental, theoretical analysis and numerical simulation can effectively predict the stress state of the structure, providing guidance for the design and application of composite structure.