摆锤冲击作用下大理岩的损伤特征研究

Damage Characterization of Marble Under Cyclic Impact Loading

为了研究局部循环冲击作用下大理岩的损伤变化特征,论文利用损伤因子定义岩石的损伤程度,借助摆锤冲击试验机对大理岩试件进行不同冲击能量下接触面积之比为1/18S的循环冲击试验,分析其不同冲击能量和冲击次数对大理岩试件的冲击损伤,损伤因子随着冲击能量和冲击次数不同的变化特征。研究结果表明:当摆锤扬角为10°时,试件未发生明显的损伤破坏,随着循环冲击次数的增加,损伤因子不断增加,当循环冲击增加到一定次数时,试件会发生宏观破坏,损伤因子会发生显著变化;随着摆锤扬角的增大,波速开始明显降低,试件发生断裂破坏时所需的冲击吸收能量和冲击次数不断减少,损伤因子增长率可达75%。考虑到矿岩对溜井井壁的冲击方式为不同接触面积的局部冲击,研究结果可以为矿山溜井井壁受矿岩冲击损伤的研究提供一个新的思路。

In order to study the damage change characteristics of marble under local cyclic impact,the paper uses the damage factor to define the damage degree of the rock.Then with the help of the pendulum impact testing machine on the marble specimen with different impact energy under the contact area ratio of 1/18 S cyclic impact test,the study analyzes the impact damage to the marble specimen with different impact energy and the number of impacts,and the change characteristics of the damage factor caused by different impact energy and the number of impacts.The results shows:when the pendulum lifting angle is 10°,the specimen does not have obvious damage;with the increase of the number of cyclic impact,the damage factor increases;when the cyclic impact increases to a certain number of times,the specimen is macroscopically damaged,and the damage factor changes significantly;with the increase of the pendulum lifting angle,the wave speed begins to decrease significantly,the impact absorbed energy and the number of impacts required during the specimen fracture damage also decreases,and the growth rate of damage factor reaches 75%.Considering that the impact mode of the rock on the shaft walls is localized impact with different contact areas,these results can provide a new idea for the study of the impact damage of rock to the shaft walls in mines.