加载速率对岩石动态断裂韧度影响的试验

Experimental Study on the Effect of Loading Rate for Dynamic Fracture Toughness of Rock

采用CCCD-SHPB(Central Cracked Circular Disk-Split Hopkinson Pressure Bar)试验系统对花岗岩试件实施不同加载速率下的纯Ι型加载试验,测得平均载荷■随时间的变化关系.将实测的载荷代入到推广的中心裂纹圆盘试件应力强度因子计算公式,获得花岗岩在不同加载速率下的动态断裂韧度,揭示加载速率与动态断裂韧度的相关性.试验结果表明,加载速率为50～350GPa·m^(1/2)/s时,随加载速率的增加,断裂韧度呈现出线性上升趋势.

By using CCCD-SHPB（central cracked circular disk-split Hopkinson pressure bar） test system the pure type Ι loading tests of granite samples under different loading rate were carried out,the relationship between the average loading curves ■ and time was measured.The things gained above are used in the promoted central cracked circle disk specimen stress intensity factors calculation formula to obtain the dynamic fracture toughness of the granite under different loading rates and reveal the relationship between loading rate and dynamic fracture toughness.The results show that in the loading rate range from 50 to 350 GPa·m^（1/2）/s,the fracture toughness has a linear upward trend with the increase of loading rate.