混沌初值敏感性在应力波检测管道损伤参数中的应用研究

项目名称： 混沌初值敏感性在应力波检测管道损伤参数中的应用研究

项目编号： No.11472146

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 马宏伟

作者单位： 青海大学

项目金额： 82万元

中文摘要： 与传统超声波无损检测相比，超声导波具有检测速度快，检测范围广等优势，已成为长距离管线检测的重要方法。目前，检测精度和检测距离以及缺陷参数识别问题已成为超声导波检测技术的难点问题。本项目拟利用混沌系统对初值敏感性，将导波信号作为混沌系统的初始输入，建立管道结构与局部损伤特征（裂纹、腐蚀坑、法兰、焊缝等），导波传播特征（在模态转换、频散、衰减、波数和信号阵列等）、以及混沌损伤因子三者之间的关系，可实现对缺陷损伤程度和损伤类型的识别；研究典型管道结构无损检测的基础数据，编制管道超声导波检测的DAC曲线和破损识别曲线，提高超声导波无损检测的操作性。本研究将通过系统的理论和实验研究，力争在超声导波检测信号的混沌检测方面获得有价值的研究成果。创新之处在于，以混沌系统初值敏感性构造导波检测指标，可提高小缺陷的检测灵敏度和延长管道有效检测距离。

中文关键词： 应力波；数值模拟；冲击响应；非线性系统；损伤识别

英文摘要： Ultrasonic guided waves have been become an important detective method for long-distance pipelines, because of their superior abilities of fast speed and wide range, to the traditional nondestructive ultrasonic inspection technology. However, the detection precision, available detection length and parameter identification of defects are the main difficult problems of ultrasonic guided wave inspection technology at present. The sensitivity of the chaotic system to initial conditions will be used to establish the relationship among the damage characteristics (crack, corrosion pit, flange and weld joint, etc.) of pipeline structures and their local positions, propagation characteristics of guided wave signals (mode transformation, frequency dispersion, attenuation, wave number and signal array etc.), and chaos damage factor in this proposal; this will achieve the identification of the type and degree of defects/damages. Based on the study on basic NDT data of typical pipe structures, the DAC curves and damage identification curves of pipes in the ultrasonic guided wave inspections will be programmed, in order to improve the operability of the proposed method. The systematic theoretical and experimental studies will be performed, attempting to achieve some valuable results in the chaos inspection aspects using ultrasonic guided wave signals. The innovation of this proposal is to develop the detection index using the sensitivity of the chaotic system to initial conditions, which is helpful to improve the detection sensitivity of micro defects and extend the effective detection distance of pipelines.

英文关键词： Stress Wave;Numerical Study;Impulse Response;Nonlinear System;Damage Identification