超高应变率下岩石的破坏机理  

Failure mechanism of rock under ultra-high strain rates

作　　者：赵高峰 孙建华[1] 李世金 张奔 ZHAO Gaofeng;SUN Jianhua;LI Shijin;ZHANG Ben(State Key Laboratory of Hydraulic Engineering Simulation and Safety,School of Civil Engineering,Tianjin University,Tianjin 300350,P.R.China)

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,建筑工程学院,天津300350

出　　处：《土木与环境工程学报（中英文）》2021年第1期11-24,共14页Journal of Civil and Environmental Engineering

基　　金：National Key R&D Program of China(Grant No.2018YFC0406804);National Natural Science Foundation of China(No.11772221)。

摘　　要：通过对大理石的轻气炮试验进行三维数值仿真重现,探索了岩石在超高应变率下的破坏机理。大理石试样中两个高速应力计的实测应力信号被用作数值模拟的匹配目标,结果表明,在高速冲击压缩载荷下,细观静水压破坏是大理石的主要破坏机制,而不是通常认为的细观剪切或拉伸破坏。此外,为再现不同冲击速度下大理石的物理实验观测数据,提出了新的考虑时间非局部效应的细观速率相关岩石破坏模型,并且发现对岩石轻气炮的数值模拟需采用准静态测量的弹性力学参数而不是超声测量的弹性参数。最后对具有不同孔隙度的虚拟岩石样本进行进一步的轻气炮数值试验,结果表明,岩石的孔隙度越大,在冲击压缩载荷下的动态强度和动力学率效应越小。We explored the failure mechanism of rock under ultra-high strain rates using 3 D numerical modeling of the light gas gun test.Based on numerical results,it concluded that mesoscopic hydrocompressive failure rather than mesoscopic shear or tensile failure is the main mechanism of rock failure under the condition of shock compressive loading.The shock wave,indicated by the stress signals of two stress gauges in the rock specimen,can be well reproduced by numerical simulation with the quasi-static rather than the dynamic elastic parameters.The simulation results indicate that the compressive shock wave involves a compressive failure loading process similar to that shown in the conventional uniaxial compressive failure test rather than the ultrasonic test.A mesoscopic-rate-dependent failure model was developed to take the dynamic effect into account.Our results revealed that larger rock porosity could result in an decrease in dynamic strength and dynamic effect under shock compressive loading.

关 键 词：动态破坏 轻气枪试验 冲击压缩荷载 格元模型 

分 类 号：TU458[建筑科学—岩土工程]