To realize robust structural design, the effects of the adhesive fillet, overlap length and unbonded area in adhesive‐bonded joints need to be fully understood and incorporated into a fatigue life estimation method. In the present work, both static and fatigue experiments are performed on six types of adhesive‐bonded joints to illuminate these effects systematically. A straightforward total fatigue life evaluation method is proposed to address these effects. A statistical crack initiation model is established based on the fatigue data of bulk adhesive specimens. Growth life is calculated using the interfacial crack model and mixed mode crack growth method. Good correlation is observed between the calculated and experimental fatigue lives. Furthermore, the effects of the adhesive fillet, overlap length and unbonded area are analysed based on both calculated and experimental results. Results indicate that adhesive fillet postpones crack initiation by reducing local strain level, both overlap length and unbonded area change the growth life by length. Besides, overlap length promotes the fraction of mode II strain energy release rate in total, reducing crack growth rates and extending growth life.

中文翻译：

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胶接缝中胶接角，重叠长度和未胶接面积影响的实验和数值评估

为了实现可靠的结构设计，需要充分理解胶接缝，胶接接头中重叠长度和未胶接面积的影响，并将其纳入疲劳寿命估算方法。在本工作中，对六种类型的胶粘接头进行了静态和疲劳试验，以系统地阐明这些影响。提出了一种简单的总疲劳寿命评估方法来解决这些影响。基于大块胶粘试样的疲劳数据建立统计裂纹萌生模型。使用界面裂纹模型和混合模式裂纹增长方法来计算生长寿命。在计算得出的疲劳寿命与实验疲劳寿命之间观察到良好的相关性。此外，胶条的效果 根据计算结果和实验结果分析重叠长度和未结合面积。结果表明，粘合剂圆角通过减小局部应变水平来延迟裂纹的萌生，重叠长度和未粘合区域都按长度改变了生长寿命。此外，重叠长度提高了模式II应变能释放速率的总和，降低了裂纹扩展速率并延长了扩展寿命。