轴向拉伸情况下岩石的动态力学特性试验研究

Mechanical properties of rock material under dynamic uniaxial tension

通过在自行研制的加载系统上对花岗岩在应变速率10-5s-1～10-1s-1范围内进行了动态直接单轴拉伸试验,并辅以巴西劈裂实验,系统、全面地研究了花岗岩在不同应变速率影响下的强度及变形特性。结果表明:岩石的抗拉强度随着应变速率的增加而增加;岩石的弹性模量也随着应变速率的增加而增加,但增加幅度小于抗拉强度的增加幅度;另外岩石的临界拉伸应变与应变速率也呈正相关性,但岩石的泊松比与应变速率的率相关性不是特别明显,表现得较为离散。并根据已有研究成果初步讨论了岩石在轴向拉伸情况的动态力学特性机理。

Dynamic direct tensile tests and Brazilian tests of granite were carried out by use of the loading system developed by the authors, with the axial strain rate ranging from 10^-5 to 10^-1 s^-1. Dynamic strength and deformation properties were studied systematically. It was indicated that the tensile strength of rock material increased with the increasing strain rate. The Young＇s modulus of the rock also increased with the increasing strain rate, but the increasing rate was less than that of tensile strength. And it was the same for the critical tensile strain. However, the Poisson＇s ratio was discrete. In addition, the mechanism of the strain rate effect of the rock material was primarily analyzed.