应力波法锚杆加固无损检测的数值模拟分析研究

NUMERICAL SIMULATION ANALYSIS OF NONDESTRUCTIVE DETECTION OF STRESS WAVE IN ANCHORAGE BOLTS

应力波法锚杆加固无损检测是一种快速、有效的无损检测方法。将锚固体中锚杆和砂浆近似看作各向同性体，应用复合材料的观点，建立砂浆锚杆在力学和物理上等效的一维匀质杆件模型，并确定了等效的工程常数。在一维杆纵向波动理论的基础上给出应力波在锚固体中传播的控制方程，对锚固体缺陷进行数值模拟，通过对控制方程的系数调整，模拟分析了不同缺陷的锚固体在冲击荷载作用下的动力响应。通过实际工程中模型锚杆的实测波形和数值模拟动测曲线进行比较分析表明，采用所建模型的理论分析结果能较好地反映实际锚杆瞬态纵向动力作用特征，激振力函数、等效参数、对锚杆纵向振动特征的模拟是有效的，对提高检测结果的准确性有较重要的意义。

Nondestructive detection of stress wave in anchorage bolts is a kind of quick and effective detection method. In this paper, bolt and mortar in anchorage system are appreciatively considered as isotropic materials. Applying composite material theory, equivalent one-dimensional physical and mechanical model of bolt and mortar is founded and equivalent engineering parameters are determined. Based on one-dimensional wave theory, the propagation equation of stress wave in anchorage system is induced. The numerical simulation of flaws in anchorage system is carried out. Through adjusting the coefficients of the dominant equation, the dynamic response of defective anchorage system under impact load can be simulated. Through comparing and analyzing, it is shown that the simulated curves are in good agreement with the waveforms obtained from model test measurements. Analytical results in theory can preferably reflect the actual dynamic character in bolt. Consequently, the mode, exciting force function, the equivalent parameters and the results of numerical simulation are proved to be correct and effective. It will play an important role in increasing the accuracy of detection results.