胶接对碳纤维层合板与铝合金板单钉连接静强度的影响

Bonding influence on static strength of single bolted joint of carbon laminates and aluminum alloy plate

开展了碳纤维层合板与铝合金板单钉连接及胶螺连接静强度拉伸实验。建立了胶螺连接有限元模型,编写子程序将三维Hashin失效准则嵌入了计算模型。对板间胶层脱黏机理进行了研究,分析了碳纤维层合板的渐进损伤过程。基于实验数据对数值计算模型进行了修正。修正后有限元模型的峰值载荷与实验值误差为2.9%,二次峰值误差为14.8%。研究表明:高强度胶黏剂能提高单钉胶螺连接结构强度和安全裕度;胶黏剂强度越高则峰值载荷越高;板间胶层脱黏后,载荷二次峰值低于初始峰值,且与无胶接单钉螺栓连接峰值载荷基本吻合;螺栓孔内注胶的胶螺连接结构的连接刚度和稳定性优于孔内无胶连接结构;本文构建的有限元模型能较准确模拟位移加载下板间胶层的脱黏机理和碳纤维层合板的渐进损伤过程。

The static strength tensile tests of single-bolted joint and bonded-bolted joint of carbon fiber laminate and aluminum alloy plate are carried out. A finite element model of the bonded-bolted joint is established. The three-dimensional Hashin failure criterion is embedded in the analysis model by subroutine programming. The debonding mechanism of the adhesive layer between the laminate and aluminum plate is studied, and the failure evolution process of the carbon fiber laminates is analyzed. The numerical model is revised based on test data. After the correction, the peak load error between the finite element model and the test value is 2.9%, and the error of the second peak is 14.8%. It is showed that high-strength adhesive improves the joint strength and expands safety margin of the single-bolted and bonded joint. The higher the adhesive strength, the higher the peak load. When the debonding occurs between the laminate and aluminum plate, the secondary peak load is lower than the initial one. The secondary peak load is consistent with the peak load of the non-adhesive single-bolted joint. The joint stiffness and stability of the bonded-bolted joint with adhesive in the bolt hole is better than that of the joint without adhesive in the bolt hole. The debonding mechanism of the adhesive layer between the laminate and aluminum plate under displacement loading and the failure evolution process of carbon fiber laminates are simulated well by the finite element model established in this paper.