加载速率对煤岩损伤及声发射特征影响的数值模拟研究

Numerical simulation study of influence of loading rate on damage and acoustic emission characteristics of coal rock

为研究加载速率对煤岩损伤及声发射特征的影响,利用RFPA2D数值模拟软件,以加载速率0.001,0.003,0.005 mm/步对煤岩试样进行数值模拟试验。结果表明,加载速率对煤岩的损伤特征和声发射特征都具有一定的影响。随着加载速率的增加,宏观损伤出现的时间逐渐减小,呈现负相关性;不同加载速率下煤样破裂过程中的声发射峰值计数和峰值能量随着加载速率的增加逐渐增大,呈现正相关关系;不同加载速率下煤样破裂过程中的声发射累计计数和累计能量随着加载速率的增加逐渐减小,呈现出负相关关系。

A numerical simulation experiment is carried out by using RFPA20 numerical simulation with theloading rate of 0. 001 , 0. 003 ,and 0. 005 mm/step in order to study on the loading rate influence of the damageand acoustic emission characteristics of coal rock. The results show that the loading rate has a certain impacton damage and acoustic emission characteristics of coal rock with the increase of the loading rate, thetime of macroscopic damage occurs gradually smaller, and a negative correlation is presented. The acoustic emissionpeak count and peak energy in the process of coal samples increased gradually under different loading,and it is shown a positive correlation. The acoustic emission cumulative counts and cumulative energy with theincrease of loading rate are gradually smaller in the process of coal samples under different loading rates,showing a negative correlation.