不同冲击波长下恒阻大变形锚杆动力学特性研究

利用改进的霍普金森冲击拉伸实验系统,研究了恒阻大变形锚杆(CRLD锚杆)在三种不同冲击波长(0.6 m,1.0 m,1.4 m)下的力学性能,并与传统强度锚杆的抗冲击特性进行了比较。同时,通过LS-DYNA进行数值分析并与实验结果相互验证。实验结果表明：冲击能量相同,冲击波长与冲击力峰值、伸长量峰值呈负相关。传统强度锚杆每次冲击后都没有明显的伸长,直至发生没有征兆的“脆断”,而CRLD锚杆在冲击过程中产生较为明显的伸长量,不会发生脆性断裂等现象,说明其在受到动力冲击时更容易发生失效,CRLD锚杆由于输出结构变形,减弱了冲击力的作用。

Experimental Study on the Effect of Impact Wavelength on the Elongation of Constant Resistance and Large Deformation Bolt

Using an improved Hopkinson impact tensile experimental system, the mechanical properties of constant resistance and large deformation anchor rods (CRLD anchor rods) under three different impact wavelengths (0.6 m, 1.0 m, 1.4 m) were studied, and the impact resistance characteristics of CRLD anchor rods were compared with those of traditional strength anchor rods. At the same time, numerical analysis was conducted through LS-DYNA and verified with experimental results. The experimental results show that the impact energy is the same, and the impact wavelength is negatively correlated with the peak value of impact force and elongation. Traditional strength bolts do not significantly elongate after each impact, until there is a "brittle fracture" without symptoms. However, CRLD bolts produce relatively significant elongation during the impact process, without brittle fracture and other phenomena, indicating that they are more prone to failure under dynamic impact. Due to deformation of the output structure, CRLD bolts weaken the impact force.