A split Hopkinson pressure bar system was used to apply a high-speed dynamic load to a flattened Brazilian disc, and the dynamic characteristics of purely type-I or -II fractures or mixed type-I-II composite fractures were studied in detail. The effect of the strain rate and the inclination angle of the prefabricated cracks was analyzed and compared with theoretical results. Furthermore, a dynamic three-dimensional numerical model was developed on the basis of the mesoscopic nonuniform distribution of materials. The failure process, failure pattern and acoustic emission performance of the disc were observed step by step in the numerical simulation. The experimental and numerical results were in good agreement and showed that the strain rate and inclination angle affected the strength, failure pattern and toughness of the dynamic fracture. This study contributes to numerical simulation in which the failure process of secondary cracks was well presented by introducing mesoscopic nonuniformity into the model.

采用分体式霍普金森压杆系统对压扁的巴西椎间盘施加高速动载荷，详细研究了纯Ⅰ型或Ⅱ型裂缝或混合Ⅰ-Ⅱ型复合裂缝的动力特性。分析了应变速率和预制裂纹倾角的影响，并与理论结果进行了比较。此外，基于材料的细观非均匀分布开发了动态三维数值模型。在数值模拟中逐步观察了圆盘的失效过程、失效模式和声发射性能。实验和数值结果吻合良好，表明应变速率和倾角影响动态断裂的强度、破坏模式和韧性。