An investigation of hygrothermal effects on adhesive materials and double lap shear joints of CFRP composite laminates
An investigation of hygrothermal effects on adhesive materials and double lap shear joints of CFRP composite laminates
复制标题
CFRP复合材料层压板粘合材料和双搭接剪切接头的湿热效应研究
DOI：
10.1016/j.compositesb.2016.01.051
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发表时间：
2016-04-15
影响因子：
13.1
通讯作者：
Guo, Xin
中科院分区：
文献类型：
--
作者：
Liu, Shufeng;Cheng, Xiaoquan;Guo, Xin
研究了湿热对用环氧胶膜SY14粘接的碳/环氧复合材料层合板双搭接剪切接头力学性能的影响。首先，用实验方法评价了胶粘剂的湿热依赖性能和复合材料叠层双搭接接头在不同环境条件下的静态响应。将标本分为室温/干(RD)、室温/湿(RW)、高温/干(ED)和高温/湿(EW)。将湿试件在90摄氏度的去离子水中浸泡60小时，高温为95摄氏度，在控制室中进行室温和高温(95摄氏度)的拉伸试验。结果表明，在潮湿环境中，复合材料的弹性模量和拉伸强度分别下降了约24%和27%。高温下材料的降解较大，但塑性显著。用目测方法研究了双搭接剪切接头的破坏模式。结果表明，干燥试件在室温下既发生粘结破坏，又发生粘结破坏。而破坏模式主要是受潮后的粘结破坏和高温下的粘结破坏。其次，利用有限元模型模拟了双搭接接头的损伤演化过程。包括水分扩散过程、膨胀应力和热应力。并考虑了湿热相关的内聚力定律来研究损伤演化。结果表明，粘结剂和粘结剂的强度越低，破坏模式越严重。吸湿对粘结强度的影响较大，破坏形式以粘结破坏为主。温度升高会严重降低胶粘剂的强度，因此胶粘剂失效占主导地位。预测的破坏载荷与试验结果吻合较好。预测的失效模式也与实验现象相吻合。(C)2016爱思唯尔有限公司。保留所有权利。
This paper was aimed to investigate the hygrothermal effects on the mechanical behavior of the double lap shear joints of Carbon/Epoxy composite laminates, which were bonded using epoxy adhesive film SY14. First, experimental method was used to evaluate the hygrothermal dependent properties of the adhesive and the static response of composite laminate double lap joints at various environment conditions. The specimens were grouped into room temperature/dry (RD), room temperature/wet (RW), elevated temperature/dry (ED) and elevated temperature/wet (EW). The wet specimens were immersed in deionized water at temperature of 90 degrees C for 60 h and the elevated temperature is 95 degrees C. Tensile tests were carried out at room temperature and elevated temperature (95 degrees C) in a controlled chamber. Results showed that the elastic modulus and tensile strength decreased about 24% and 27% respectively after exposure to humidity environment. And a large degradation was found when exposure to high temperature while the plasticity became notable. The failure modes of the double lap shear joints were studied by visual inspection. It was found that both adhesive and cohesive failure happened for dry specimens at room temperature. While failure modes were dominated by cohesive failure after moisture exposure and adhesive failure at elevated temperature. Second, a finite element model was utilized to simulate the damage evolution of the double lap joints. The moisture diffusion process, swelling stress and thermal stress were included. And hygrothermal dependent cohesive law was considered to study the damage evolution. It revealed that failure modes were highly dependent on the weaker strength of adhesive and cohesive. Moisture absorption caused large degradation in cohesive strength, so the failure modes were mostly cohesive failure. Elevated temperature decreases strength of adhesive seriously, so adhesive failure dominates. Good agreement was achieved between the predicted failure loads and experimental results. And the predicted failure modes were also consistent with the experimental phenomenon. (C) 2016 Elsevier Ltd. All rights reserved.