Dynamic fracture tests are carried out for four groups of hole-containing edge impacted PMMA specimens. The crack growth velocity, crack path, and dynamic toughness are extracted from the experiments using high-speed photography and digital image correlation. The importance of the interaction between the in-coming stress wave and the pre-existing hole is revealed and analyzed. We found that the location and size of the pre-existing holes have a significant effect on the rate and spatial distribution build-up of strain energy near the crack tip due to wave scattering effects from the holes. A micromechanical damage model is calibrated to the experimental data from two of the specimens' designs and evaluated for its predictive capabilities using the other experimental configurations. The studied model is shown to be in reasonable agreement with the experimental data, and its limitations are discussed.

对四组含孔边缘冲击的 PMMA 试样进行了动态断裂试验。使用高速摄影和数字图像相关从实验中提取裂纹扩展速度、裂纹路径和动态韧性。揭示并分析了传入应力波与预先存在的孔之间相互作用的重要性。我们发现，由于来自孔的波散射效应，预先存在的孔的位置和大小对裂纹尖端附近应变能的速率和空间分布积累有显着影响。微机械损伤模型根据来自两个样本设计的实验数据进行校准，并使用其他实验配置评估其预测能力。