Adhesively bonding composite components is a reliable alternative to conventional joining processes that minimizes part weight and reduces fabrication costs. Regarding performance and reliability, of particular interest is developing adherend surface treatments that enhance adhesion of the joint interfaces in aggressive chemical environments. Using fracture mechanics-based adhesion metrologies, critical and subcritical crack growth were evaluated for several peel-ply-treated, adhesively bonded composite joints. Fracture toughness, G_c, and corresponding failure modes were evaluated for specimens constructed using two different bonding processes (co-bonding and secondary bonding) and four different peel ply treatments. Environmentally assisted crack growth was evaluated as a function of time in several environments: humid, high temperature humid, and hydraulic fluid immersion. It is shown that humid environments accelerate crack growth rates, da/dt, relative to the strain energy release rate, G. This effect was amplified at elevated temperatures and further amplified in the presence of hydraulic fluid.

胶粘复合材料组件是传统连接工艺的可靠替代方案，可最大程度地减少零件重量并降低制造成本。关于性能和可靠性，特别感兴趣的是开发在侵蚀性化学环境中增强接头界面粘合力的被粘物表面处理。使用基于断裂力学的粘合方法，对几种经剥离处理，粘合的复合材料接头的临界和亚临界裂纹增长进行了评估。断裂韧性，G _c，并对使用两种不同的粘合工艺（共粘合和二次粘合）和四种不同的剥离层处理方法构造的样品评估了相应的破坏模式。在以下几种环境中，评估了环境辅助裂纹扩展随时间的变化情况：潮湿，高温潮湿和液压油浸没。结果表明，相对于应变能释放速率G，潮湿的环境加速了裂纹扩展速率da / dt。这种影响在高温下会放大，在液压油存在的情况下会进一步放大。