加载速率影响的单裂隙类岩石试样能量演化规律

Energy evolution of single fractured rock-like specimens affected by loading rate

为了研究加载速率对单裂隙类岩石试样破坏过程中能量演化进程的影响规律,分析裂隙类岩石试样在不同加载速率下的能量响应特征,以预埋金属薄片方法制作的裂隙类岩石试件为研究对象,基于RMT-150B对单裂隙类岩石试样进行四级加载速率下的单轴压缩试验,获得四级加载速率下裂隙类岩石试样力学性能。试验结果表明:单裂隙类岩石试样峰值强度与加载速率呈正相关性,但增长速率随加载速率的增加而减小;当加载速度不断增大时,峰值处试样弹性应变能积聚能力增强,但是耗散应变能随加载速率的增大而逐渐减小;裂隙试样在峰值后会累积弹性应变能,但其积聚能力随加载速率的增大而有所削弱;裂隙试样耗散应变能转化速率在峰值前处于较低水平,在峰值后伴随宏观破裂面的贯通而骤增,表明单裂隙类岩石试样内部能量演化进程与其破坏规律之间具有内在联系。

To investigate the influence of loading rate on fracture characteristic and energy evolution process of single fissure specimen,rock-like specimens made by embedded aluminium alloy sheet were tested at different loading rates under uniaxial compression.It shows that the peak strength and modulus of elasticity correlate positively with the loading rate,but their growth rates decrease with the increase of loading rate;the elastic strain energy increases with the increase of loading rate at the peak strength,while the dissipated strain energy decreases with the increase of loading rate;the elastic strain energy of the fracture body still accumulates after peak value,but the capability to accumulate elastic strain energy decreases with the increase of loading rate;the transformation rate of dissipated strain energy of the fracture body is at a low level before the peak value,and increases sharply with the penetration of macro-fracture surface after the peak value;the damage degree of the fracture body varies with the loading rate,which indicates that there is an intrinsic relationship between the energy evolution process and failure law.