GFRP锚杆无损检测应力波频率的选择

Selection of Stress Wave Frequency for Non-destructive Testing of GFRP Bolt

锚固工程属于隐蔽工程,为能够掌握锚杆的锚固质量以及损伤情况,可采用无损检测技术对锚杆的锚固情况进行检测分析,来判断锚杆的完整性以及锚固工程的可靠性,应力波检测法是无损检测技术的一种方法。目前,锚杆的应力波无损检测技术的研究大多是针对金属材质的锚杆,而对非金属材质的锚杆研究较少,采用FLAC^(3D)对玻璃钢(GFRP)锚杆进行无损检测数值模拟,利用该软件在非线性动力学分析上的优势,建立计算模型,记录锚固系统在不同频率下的速度时程曲线,分析了应力波在不同频率下的传播特性以及衰减规律。根据固结波速的衰减速率得出结论:玻璃钢锚杆无损检测理想应力波激发频率在30~40 k Hz范围内。

The anchoring engineering is belong to the concealed engineering. In order to grasp the anchoring quality and damage of the rock bolts,the anchorage system can be tested and analyzed by using the nondestructive testing technology to judge the integrity of the anchor and the reliability,and stress wave detection is a method of non-destructive testing technology.At present,the study of non-destructive testing technology based on stress wave of anchorage system is mostly for the anchors with metal materials,and the study of the ones with non-metallic materials is less. FLAC^（3D）software is used to simulate the nondestructive testing of glass fiber reinforced plastic（ GFRP） rock bolts. Based on the advantages of FLAC^（3D）software in nonlinear dynamic analysis area,the calculation model is established to record the velocity time curve of the anchoring system in different frequencies,besides,the propagation characteristics and attenuation laws of the stress wave in different frequencies are analyzed. According to the attenuation rate of consolidation wave velocity,the ideal excitation frequency of stress wave of GFRP bolt is from 30 k Hz and 40 k Hz.