服役温度对铝合金-碳纤维增强树脂复合材料粘接接头准静态失效的影响

Effect of service temperature on quasi-static failure of aluminum alloy-carbon fiber reinforced polymer composite bonded joints

为了研究服役温度对铝合金-碳纤维增强树脂(CFRP)复合材料粘接接头准静态失效的影响,本文加工了铝合金-CFRP复合材料粘接接头。考虑车辆实际运行工况下的服役温度,选取低温(-40℃)、常温(20℃)和高温(80℃)三种环境温度,结合设计的Arcan夹具对铝合金-CFRP复合材料粘接接头分别进行1 mm/min和100 mm/min的准静态试验,得到不同温度下铝合金-CFRP复合材料对接接头(BJs)、45°嵌接接头(45°SJs)和剪切接头(TSJs)的准静态失效强度,并结合失效断面对接头失效形式进行分析,建立了失效准则方程和三维响应曲面。结果表明:不同加载速率下的铝合金-CFRP复合材料粘接接头失效强度在高温环境下均呈明显的下降趋势,在低温环境下均呈一定程度的上升趋势。高温下的失效模式为胶层的内聚失效,低温下的失效模式中纤维撕裂的比例上升。相对于1 mm/min加载速率下的准静态失效强度,各温度和应力状态下的铝合金-CFRP复合材料粘接接头在100 mm/min加载速率下的准静态失效强度明显提高。

In order to study the effect of service temperature on quasi-static failure of aluminum-carbon fiber reinforced polymer(CFRP) composite bonded joints, aluminum alloy-CFRP composite bonded joints were processed.Considering the service temperature under actual operating conditions of the vehicle, three ambient temperatures of low temperature(-40℃), normal temperature(20℃) and high temperature(80℃) were selected, and the loading rates were 1 mm/min and 100 mm/min in combination with the designed Arcan fixture. The quasi-static failure strength of aluminum alloy-CFRP composite butt joints(BJs), 45° scarph joints(45°SJs) and shear joints(TSJs) at different temperatures were obtained. Combined with the failure section to analyze the failure mode of the joint,the failure criterion equation and the three-dimensional response surface were established. The results show that the quasi-static failure strength of aluminum alloy-CFRP composite bonded joints at different loading rates show a significant downward trend in high temperature environment, and it shows a certain upward trend in low temperature environment. The failure mode in high temperature environment is the cohesive failure of adhesive layer, and the ratio of fiber tear increases in low temperature environment. Compared with the quasi-static failure strength at the loading rate of 1 mm/min, the quasi-static failure strength of the aluminum alloy-CFRP composite bonded joint under different temperature and stress conditions is obviously improved at the loading rate of 100 mm/min.