| 钱骥,陈鑫,杨金川.小波时-频变换的高强钢丝弹性波传播模态分析*[J].,2017,36(6):548-557 |
| 小波时-频变换的高强钢丝弹性波传播模态分析* |
| Modal analysis of elastic wave propagating in highstrength steel wires based on wavelet time-frequency analysis |
| 投稿时间：2017-05-19 修订日期：2017-10-24 |
| 中文摘要: |
| 超声导波是近年来桥梁拉索无损检测研究的重要方法之一。针对弹性波在高强钢丝介质中传播的多模态频散问题，采用单节点时程波形的小波时频变换进行混叠信号的模态识别分离。通过数值求解Pochhammer频率超越方程，计算得到0-1.5MHz范围内纵向导波模态理论频散曲线；采用有限元模拟半波正弦脉冲激励导波在钢丝中传播过程，由小波时-频变换得到导波模态分布，并进行了试验对比分析。结果表明，在0-1.5MHz频率范围内，基于有限元模拟结果的小波时-频变换能够有效的识别高强钢丝中被激起的第一、二、三阶纵向导波模态；钢丝端部实测时程波形的小波时频变换结果与理论纵向导波模态吻合良好，经分离后的一阶纵向导波模态能量占比达92%。 |
| 英文摘要: |
| Ultrasonic guide wave is one of effective methods in studying nondestructive testing in bridge cables. In view of the multi-modal dispersion characteristics of elastic wave in high strength steel wires, this paper adopts the wavelet time-frequency transform method to identify and separate multi-modal signals, which is from one point vibration.Frequency dispersion curves of longitudinal modes in the range of 0-1.5MHz were obtained by solving Pochhammer frequency equation with numerical method. Then, finite element method was used to simulate the guide wave propagating in steel wire which is excited by a half sine pulse, and the guide wave modal is acquired by wavelet time-frequency analysis, and the experiment comparison analysis is carried out finally. The results show that wavelet time-frequency transform method can accurately recognize the first, second and third order longitudinal modals in the frequency range of 0-1.5MHz;The wavelet time-frequency transform of time-histories data measured in the end section is in good agreement with the theoretical result, and the energy of separated first order longitudinal mode accounting for 92%. |
| DOI：10.11684/j.issn.1000-310X.2017.06.011 |
| 中文关键词: 高强钢丝，弹性波，纵向导波模态，小波时-频变换 |
| 英文关键词: High strength steel wire, Elastic wave, Longitudinal guide wave mode Wavelet time-frequency analysis |
| 基金项目:国家自然科学基金项目 (51408090, 51478347), 重庆市基础与前沿研究计划项目 (cstc2014jcyjA0947, cstc2015jcyjB0014), 重庆交通 大学研究生教育创新基金 (20160106) |
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