灰岩和白云岩动态压缩力学性能的SHPB实验

为了得到爆破荷载作用下岩石的破坏特性及爆破振动波的传播特性,利用RMT-150C多功能实验机和改进后的ф50mm的分离式Hopkinson压杆装置,分别研究灰岩和白云岩试件的静态力学特性和在5种不同应变率等级下的动态力学性能。实验结果表明,随着平均应变率的增加,灰岩和白云岩试件的动态抗压强度、峰值应变、吸收能、比能量吸收值以及破碎程度都明显增加,表现出显著的应变率效应,而初始弹性模量对应变率的相关性不敏感。从岩石的动态抗压强度和能量吸收两个方面,对比分析灰岩和白云岩动态力学性能的共性和差异性,更合理地解释了岩石在动态冲击荷载下的破坏本质。

SHPB experiment on dynamic compressive mechanical properties of limestone and dolomite

In order to obtain the failure characteristics of rock under blasting load and the propagation characteristics of blasting vibration wave,the RMT-150C multi-function testing machine and the improved φ50 mm split Hopkinson pressure bar testing equipment were used. The static mechanical properties of limestone and dolomite specimens and their dynamic mechanical pro-perties at five different strain rate levels were studied.Experimental results showed that with the increasing of average strain rate,the dynamic compressive strength,peak strain,absorption energy,specific energy absorption and crushing degree of limestone and dolostone samples increased significantly,and it showed the significant strain rate effect.While the initial elastic mo-dulus was insensitive to the strain rate.From dynamic compressive strength and energy absorption of rock, the dynamic mechanical properties of limestone and dolomite commonalities and differences were comparatively analyzed and the nature of the damage of rock under dynamic impact loading was reasonably explained.