基于电磁超声导波技术的锚杆声学特征与智能检测研究

The anchoring technology of bolt is an important supporting means in underground engineering and side slope management. Anchoring quality is one of the key factors influencing engineering quality and safety. Nowadays, it is the difficult in the world for the high precision intelligent detection of rock bolt quality. So, using electromagnetic ultrasonic guided waves technology to detect rock bolt, the research on theory and methods have important theoretical and practical significance for the safety of underground engineering. . Using pattern recognition, modern information processing technology and intelligent control theory, electromagnetic ultrasonic guided wave detection technology based on self-excitation and self-acquisition mode is presented to detect anchor quality firstly, the research is about bolt mechanism with electromagnetic excitation is studied. Theoretical model of acoustic characteristics related to bolt's mechanical properties is established, the guided waves dispersion curves, dispersive wave group characteristics based on magnetostrictive mechanism are calculated by using numerical simulation method, the best working frequency band is got. For a coil having exciting and receiving ability, the mechanism between guided waves and different type of defects in rock bolt are studied. The factors which effect Magneto mechanical energy conversion efficiency and wave modal are studied, such as the excitation magnetic field, excitation types, bias magnetic field intensity, magnetic field distribution, the current pulse, parameters outside magnetic field, and the coil shape is conformed and Optimized. Using the Spectral kurtosis method to remove the noises, defect types are got using probabilistic neural network. A prediction method would be proposed based on multi-source information fusion, so the theoretical basis are founded for quality intelligent detecting.

锚杆锚固技术是地下工程及边坡治理的重要支护手段，锚固质量的好坏关系着工程质量和安全，因此，基于电磁超声导波技术的锚杆质量智能检测的理论与方法研究，对保障地下工程安全等具有重要的理论意义和实用价值。项目以模式识别、现代信息处理技术、智能控制理论为工具，首次将自激自收模式下的电磁超声导波检测技术应用于锚杆质量检测中，解决锚杆质量智能检测相关基础科学问题。建立锚杆电磁激励情况下的声学特性理论模型，运用数值模拟方法计算基于磁致伸缩机理的锚杆中导波传播的频散特性，频散波组特征；研究自激自收模式下超声导波与锚杆锚固系统中不同缺陷相互作用机理；研究激励磁场、激励方式、偏置磁场磁场强度对导波模态和磁-机换能效率的影响，确定电流脉冲、外部磁场的参数以及线圈的形状并进行优化；利用谱峭度方法完成回波信号滤波，概率神经网络完成锚杆锚固缺陷分类检测；提出基于多源信息融合方法，完成在役锚杆锚固质量的智能检测。

锚杆锚固技术是地下工程及边坡治理的重要支护手段，锚固质量的好坏关系着工程质量和安全，因此，基于电磁超声导波技术的锚杆质量智能检测的理论与方法研究，对保障地下工程安全等具有重要的理论意义和实用价值。项目以模式识别、现代信息处理技术、智能控制理论为工具，将自激自收模式下的电磁超声导波检测技术应用于锚杆质量检测中，解决锚杆质量智能检测相关基础科学问题。建立了锚杆电磁激励情况下的声学特性理论模型，运用数值模拟方法计算基于磁致伸缩机理的锚杆中导波传播的频散特性，频散波组特征；研究了自激自收模式下超声导波与锚杆锚固系统中不同缺陷相互作用机理；激励磁场、激励方式、偏置磁场磁场强度对导波模态和磁-机换能效率的影响，确定电流脉冲、外部磁场的参数以及线圈的形状并进行优化；利用谱峭度方法完成回波信号滤波，概率神经网络完成锚杆锚固缺陷分类检测；提出基于多源信息融合方法，完成在役锚杆锚固质量的智能检测。