锚杆侧向冲击载荷下动力响应及抗冲击机理

为了研究冲击载荷作用下锚杆的动态力学性能,测试了5种不同材质的锚杆杆体力学参数。采用自由落锤冲击实验装置对不同锚杆进行了侧向抗冲击性能实验,分析了侧向冲击载荷下锚杆的动力响应。进行了5种不同冲击高度的侧向抗冲击实验,得到不同冲击高度下不同锚杆的冲击动态响应曲线,锚杆表面轴向的应变时程曲线,冲击作用点的力-位移时程曲线。研究发现,在相同冲击能量下,锚杆冲击吸收功越高冲击峰值载荷越小,冲击作用时间随着冲击高度增大逐渐减小;冲击吸收功越高,锚杆应变峰值及残余应变越大;不同锚杆冲击力峰值和最大位移明显不同,峰值强度和最大位移越大,破断能越大。对锚杆抗冲击机理进行了研究,发现控制材质中有益及有害元素含量,可提高锚杆的抗冲击性能。测试了断口组织和金相组织,得到锚杆冲击吸收功越高,晶粒度级别越高的结论。

Response and impact mechanism of rock bolt under lateral dynamic impact load

In order to study the dynamic mechanical properties of rock bolt under impact load，the mechanical properties of five different material rock bolts were tested.Lateral impact resistance test on the rock bolts was carried out using a free-fall hammer impact test device to evaluate the dynamic response of the rock bolts.The lateral impact test was performed with five different impact heights to obtain the dynamic impact response curve，the bolt axial strain-time curve，and the force-displacement-time curve at the impact point.The study found that under the condition of the same impact energy，the higher the impact absorbed energy of rock bolt，the smaller the impact peak load.Impact reaction time increases as the impact height decreases.The higher the impact absorbed energy of the rock bolt，the greater the peak strain and residual strain.The distinct differences in the impact peak load and the maximum displacement were observed among the different rock bolts.The larger the peak strength and the maximum displacement，the higher the breaking energy.It was also found that controlling the material content of beneficial and harmful elements can improve the impact resistance of the rock bolts.In addition，the microstructure and organization of the rock bolt fracture profiles were analyzed and it was found that the greater the impact absorbed energy of the rock bolt，the higher the grain size level.