应力波穿越岩石节理时能量耗散规律的实验研究

Experimental Study on Rule of Energy Dissipation of Stress Wave across Rock Joint

采用材料试验机和大尺度激光表面仪对大理岩和花岗岩两种岩石进行三点弯曲和粗糙断裂面的扫描实验,详细地分析了粗糙断裂面的分形特征。通过SHPB实验,研究并提出了波能量耗散与断裂面分形维数的定量关系;分析了分形维数对波能量耗散的影响规律。研究得出以下结论:1)随着粗糙断裂面分形维数的增大,通过断裂面时应力波能耗将相应增加;2)应力波能量主要是以热能和塑性变形能耗散。分形维数越大,比表面积则越大,粗糙表面粒子相互摩擦和挤压程度相应增加,导致波的机械能转化成热能和塑性变形能部分增加,因而波动能量耗散越大。

Coarse character of fracture section and fractal characteristics of marble and granite were particularly analyzed by using material testing machine and large-scale profilometer based on three-point bending experiment and coarse fracture section scanning.Through SHPB experiment,the quantitative relation between wave energy dissipation and fractal dimension of fracture section was studied and presented.Rule about influence of fractal dimension on wave energy dissipation was analyzed.Following conclusions are drawn from above investigation： 1） With the increase of coarse fracture section fractal dimension,stress wave energy dissipation augments correspondently;2） Stress wave energy is dissipated in form of heat and plastic deformation energy.Bigger the fractal dimension is,larger the specific surface area is.So the mutual friction and degree of clash among granules rise correspondently.Thus,the part of mechanical energy transforming into heat and plastic deformation energy augments.Therefore,the wave energy dissipation is severer.