摘要
检测信号底端反射微弱,影响杆底信号的准确识别。通过在杆底附加对超声波绝缘的介质(沥青、橡胶)来增强锚杆底端检测信号的反射强度。依据检测信号的幅频、标准差、有效值、信号幅值等特征,分析锚杆底端不同介质对杆底信号的增强作用与在分级载荷条件下不同介质对应力波特性的影响,并通过数值模拟验证了此方法的有效性。研究结果表明:在杆底附加沥青或橡胶可以增强无损检测时锚杆的底端反射信号。该方法使应力波振幅、标准差、有效值增大,增加了检测信号强度,可以有效提高底端反射信号的识别精度;对附加不同介质的锚杆施加轴向载荷,随着荷载的增大,检测信号的有效值和幅值标准差会逐渐减小,固结波速会随着轴向载荷的增大而增大;在数值模拟中,杆底介质可以增大加速度幅值,减少能量衰减,波形特性更加明显;杆底反射信号与杆底介质弹性模量存在一定关系。
The reflection at the bottom of the detection signal is weak,which affects the accurate identification of the signal at the rod bottom.The reflection intensity of the detection signal at the rod bottom is enhanced by adding to the ultrasonic insulating mediums(asphalt,rubber)at the rod bottom.According to the characteristics of the detection signal,such as amplitude,standard deviation,effective value and signal amplitude,the enhancement effect of different mediums at the rod bottom and the influence of different mediums on the stress wave behavior under the condition of graded load are analyzed,and the effectiveness of this method is verified by numerical simulation.The results show that adding asphalt or rubber to the rod bottom can enhance the reflected signal of the rod bottom during nondestructive testing.This method increases the amplitude,standard deviation and effective value of the stress wave,increases the strength of the detection signal,and can effectively improve the identification accuracy of the reflected signal of the bottom.The effective value and amplitude standard deviation of the detection signal will gradually decrease with the increase of the load applied to the anchor rod with different bottom mediums, and the consolidation wave velocity will increase by the increase of the axial load. In numerical simulation, the rod bottom mediums can increase the acceleration amplitude, reduce the energy attenuation, and the waveform characteristics are more obvious. There is a certain relationship between the reflected signal of the rod bottom and the elastic modulus of the medium of the rod bottom.
作者
赵毅
赵金昌
牛少卿
赵胤翔
常乐
袁强
李铭
ZHAO Yi;ZHAO Jinchang;NIU Shaoqing;ZHAO Yinxiang;CHANG Le;YUAN Qiang;LI Ming(College of Mining Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Middle Yellow River(Shanxi)Transportation Technology Group Co.,Ltd.,Taiyuan 030006,China)
出处
《中国矿业》
2023年第12期115-122,共8页
China Mining Magazine
基金
国家自然科学基金项目资助(编号:51574174)。
关键词
锚杆无损检测
杆底介质
杆底信号
信号强度
能量衰减
rod nondestructive testing
rod bottom medium
rod bottom signal
signal strength
energy attenuation
