岩石巴西圆盘的SHPB试验分析

Dynamic flattened Brazilian disc test using SHPB

为了研究花岗岩、千枚岩、磁铁石英岩不同应变率下三种岩石的拉伸敏感系数、弹性模量、能量耗散特征和破坏方式的变化规律,利用霍普金森试验装置对三种岩石进行动态平台巴西圆盘劈裂拉伸试验,试验结果表明:三种岩石的拉伸敏感系数随应变率的提高而增大,且应变率对拉伸敏感系数存在突变阈值;千枚岩和磁铁石英岩的弹性模量随应变率的增加而增大,花岗岩的弹性模量在应变率达到247.1 s-1以后基本不变;入射能、反射能、吸收能随着应变率的提高而增加,但试件吸收的能量相对于入射能是减小的,而透射能基本保持不变;三种岩石均沿加载直径方向劈裂,由中心起裂,满足了巴西圆盘试验的有效性,当应变率较大时,会在试样的加载端部的三角区出现粉碎区。

The dynamic split tensile properties were studied on three rock of granite, phyllite, magnetite under using SI-IPB test system, The changing rules of tensile sensitivity coefficient, tensile modulus, energy dissipition characteristics and failure modes were analyzed. Experimental results show that the tensile sensitivity coefficients of three rocks increase with the increase of strain rate, and strain rate on tensile sensitivity coefficients mutation threshold; Tensile modulus of phyllite and magnetite increase with the increase of strain rate, the ten- sile modulus of granite was basically unchanged at the rate of 247.1 s＂; the incident energy, the reflection ener- gy, and the absorption energy increased with the increase of strain rate, but the absorption energy of speci- mens were reduced relative to the incident energy, and the transmission energy could remain basically unchanged; Three rock were all along the loading diameter direction splitting with center crack, mceting the ef- fectiveness of Brazilian disc test and appeared the crush zone in sample loading end of triangular area when the strain rate was larger.