Curved laminates in aero-structures, such as the L-angle sections where webs and flanges meet, are prone to delamination due to high interlaminar stresses in these regions. Some efforts to investigate delamination in these structures can be found in the literature but commonly structures are limited to unidirectional layups or modelling approaches are constrained to the cohesive element based methods. In this work, multi-directional L-angle laminates were manufactured using unidirectional prepregs and tested under four-point bending load conditions to examine the interface damage. Acoustic emission technique was used to assist the capture of damage initiation and propagation. Three interface modelling strategies for predicting delamination, namely cohesive element, cohesive surface and perfectly bonded interface were used in the numerical study. The interface damage behaviour was successfully predicted by the simulation methods and differences among the strategies were compared.

中文翻译：

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四点弯曲下复合L角截面界面损伤的实验与数值研究

航空结构中的弯曲层压板，例如腹板和翼缘相交的 L 角截面，由于这些区域的层间应力高，容易分层。一些研究这些结构分层的努力可以在文献中找到，但通常结构仅限于单向铺设或建模方法仅限于基于内聚元素的方法。在这项工作中，使用单向预浸料制造多向 L 角层压板，并在四点弯曲载荷条件下进行测试，以检查界面损坏。声发射技术被用来帮助捕获损伤的开始和传播。在数值研究中使用了三种预测分层的界面建模策略，即粘性元素、粘性表面和完美结合的界面。