摘要
分析了自由钢杆与置于土壤中钢杆的频散曲线,并利用所建立的试验系统,采用导波技术,对上述两种锚杆的长度进行了检测。结果表明,频散曲线可以作为导波检测的理论指导,利用频散曲线选择合适的频率范围,通过激励纵向轴对称L(0,1)模态的导波可有效地检测锚杆长度;与置于空气中锚杆相比,置于土壤中锚杆的端面回波的信号幅度有所衰减,并且利用L(0,1)模态实现了对埋于土壤中锚杆缺陷的检测。
Dispersion curves of free bar and steel bar embedded in the soil were analyzed. With a testing system, guided wave testing was carried out on the rock bolts which was free and embedded in the soil to inspect the length of rock bolts. Results showed that dispersion might direct the guided waves testing in theory; a suitable frequency range was chosen by analyzing dispersion curves and it was effective for inspecting the length of rock bolt using axisymmetric L（0,1） mode of ultrasonic guided waves. Compared to the rock bolts in the air, the amplitude of signal received from the rock bolt end embedded in the soil was damped. Therefore the defect in bolt embedded in soil could be detected by L（0.1）.
出处
《无损检测》
北大核心
2007年第5期237-240,共4页
Nondestructive Testing
基金
北京市教委科技发展计划重点项目(KZ200510005004)
北京市自然科学基金项目(8062008)
国家自然科学基金(10602004)
关键词
超声导波
锚杆长度
缺陷
纵向模态
Ultrasonic guided wave
Length of rock bolt
Defect
Longitudinal mode
