应力波作用下三点弯曲梁破坏过程数值模拟

Numerical Simulation of Failure Process of Three-Point Bending Beam under Impact

岩石类准脆性材料三点弯曲梁冲击荷载作用下的破坏受应力波加载速率以及应力波峰值的影响。使用新发展的并行RFPA2D-Dynamic数值模拟工具对三点弯曲梁冲击荷载作用下的破坏过程进行了数值模拟,研究了不同加载速率和加载峰值的破坏规律。数值模拟结果与物理实验结果具有较好的一致性。在低加载速率下,三点弯曲梁发生拉伸破坏,且只出现一条裂纹;在较大加载速率时出现多条平行拉伸裂纹;在大加载速率时出现拉伸、剪切复合裂纹。应力波峰值较小时形成单一的拉伸裂纹,而随着加载峰值的提高,形成多条平行拉伸裂纹。

The failure of three-point bending beam of quasi-brittle material such as the rock under impact loads is affected by loading rate and peak of the stress wave. The failure process of the beam is simulated by parallelized RFPA2D-Dynamic with Open MP and the characteristics are studied under different loading rates and peak wave stress load. Numerical simulation and physical experiment results have good consistency. Under the low loading rate, the three-point bending beam gives tensile failure with only one crack; under larger loading rate, multiple parallel tensile cracks appear; under large loading rate the tensile shear mixed mode crack grow. Under small stress wave peak loading, the specimen forms single stretching crack. With the loading peak increase, the multiple parallel tensile cracks are formed.