基于损伤权重的碳纤维复合材料/铝合金胶铆混合连接接头疲劳寿命预测

Fatigue life prediction of carbon fiber reinforced polymer /aluminum alloy riveted-bonded hybrid joints based on damage contribution

  • 摘要: 胶铆混合连接因其高承载能力和较好的服役性能,被广泛应用于碳纤维复合材料与金属的连接,然而其多材料疲劳损伤问题严重影响了结构安全性及寿命。针对碳纤维复合材料/铝合金胶铆混合连接接头,提出基于损伤权重的多材料疲劳寿命仿真预测方法,结合试验探究了不同载荷水平下碳纤维复合材料/铝板/铆钉的失效竞争演变规律。同时开展了胶层厚度、搭接长度和铆钉数量等参数对混合接头疲劳寿命的影响研究。结果表明:胶铆混合接头的疲劳寿命受多参数耦合影响显著,当搭接长度较小且铆钉数量较少时,疲劳寿命随胶层厚度的增大呈非线性衰减;胶层厚度一定时,搭接长度对疲劳寿命的影响非单调,最优值取决于胶层厚度和载荷水平;进一步发现铆钉数量对疲劳寿命的影响表现出对载荷水平的显著依赖性。同时,疲劳寿命的仿真预测与试验结果的相对误差在±10%以内,且能有效预测接头的疲劳失效模式,可为复合材料-金属异质连接的抗疲劳优化设计提供参考。

     

    Abstract: Riveted-bonded hybrid joining method is widely used in the connection between carbon fiber reinforced polymer (CFRP) and metals due to its high load-bearing capacity and good service performance. However, fatigue-induced damage in multi-materials poses a critical threat to structural safety and service life. For the CFRP/aluminum alloy riveted-bonded hybrid joints, a multi-material fatigue life simulation-based prediction method was proposed based on the damage contribution. The failure competition evolution law of CFRP/ aluminum plate/ rivet under different load levels was explored through experiments. Meanwhile, the influences of parameters such as adhesive layer thickness, overlap length and number of rivets on its fatigue life were also investigated. The results show that the fatigue life of the adhesive-riveted hybrid joint is significantly affected by the coupling of multiple parameters. When the overlap length is small and the number of rivets is low, the fatigue life decreases nonlinearly with the increase of the adhesive layer thickness. When the thickness of the adhesive layer is fixed, the influence of the lap length on the fatigue life is non-monotonic, and the optimal value depends on the adhesive layer thickness and the load level. It is further found that the influence of the number of rivets on the fatigue life shows a significant dependence on the load level. Meanwhile, the numerical simulations demonstrate good agreement with experimental data, with relative errors of fatigue life prediction constrained within ±10%. The validated models reliably capture the fatigue failure modes of hybrid joints, providing critical references for fatigue-resistant optimization of composite-metal hybrid connections.

     

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