Considering failures during machinery processes such as drilling, a precautionary analysis involving delamination and the corresponding dissipated energy is required, especially for composite structures. In this context, because of the complexity of both the analysis procedure and experimental test setup, most studies prefer to represent mode I and III interlaminar crack propagation instead of that involving mode II. Therefore, in this study, the effect of mode II delamination and corresponding interlaminar crack propagation was considered during the drilling process of multilayered glass/polyester composites using both numerical and experimental approaches. In the experimental procedure, the mechanical properties of the glass/polyester specimens were obtained according to ASTM D3039. In addition, the interlaminar mixed-mode (I/II) loadings were determined using an ARCAN test fixture so that the fracture toughness of glass/polyester could then be identified. The mode II critical strain energy release rate (CSERR) was then obtained using an experimental test performed using an ARCAN fixture and the virtual crack closure technique (VCCT). It was determined that the numerical approach was in accordance with the experiments, and more than 95% of crack propagation could be attributed to mode II compared to the two other modes.

考虑到诸如钻孔等机械过程中的故障，需要进行涉及分层和相应耗散能量的预防性分析，尤其是对于复合结构。在这种情况下，由于分析程序和实验测试装置的复杂性，大多数研究倾向于表示模式I和III的层间裂纹扩展，而不是模式II。因此，在这项研究中，采用数值和实验方法，在多层玻璃/聚酯复合材料的钻孔过程中考虑了II型分层和相应的层间裂纹扩展的影响。在实验过程中，根据ASTM D3039获得了玻璃/聚酯样品的机械性能。此外，使用ARCAN测试夹具确定层间混合模式（I / II）载荷，从而可以确定玻璃/聚酯的断裂韧性。然后，使用使用ARCAN夹具和虚拟裂纹闭合技术（VCCT）进行的实验测试，获得II型临界应变能释放速率（CSERR）。确定数值方法与实验一致，与其他两种模式相比，模式II可以将超过95％的裂纹扩展归因于模式II。