复合材料的宽带导波信息理解与损伤评价方法研究

Damage detection and evaluation of composite structures is very important for many advanced equipments in several fields (e.g., aviation, energy and ships) to avoid fatal accidents. The broadband ultrasonic guided waves could be used for the evaluation of the security and reliability of structures because of the abundant structural information they covered. Thus it becomes a focus of the further reaserch that applying broadband guided waves for the nondestructive testing of composite structures. The motivation and objective of this project is to establish a systematic strategy for nondestructive testing of composite structures via broadband guided waves. The information interpretation is investigated firstly. Then, a mode separation methodology is established to alleviate the background noise, and thus the relation between the damage and the guided wave information could be obtained. On this basis, the time-frequency mapping of dispersion characteristics and the model of multi- parameter matching in the anisotropic structures is established for mode identification and source tracing. In addition, the strategy for feature extraction is studied, where the index set that is sensitive to the damage could be gained and its evolution associated with the extent and types of damages could be studied. These methods could form the theory and methodology basis of the nondestructive testing and structural health evaluation for composites. Furthermore, this project may provide proofs for the condition assessment, health maintenance and effective managment of the on-service composites.

随着复合材料在航空、能源、船舶等领域高端装备中应用量的迅猛增长，其损伤检测与评估已成为这些装备安全、可靠运行的迫切需求。相比窄带导波，宽带导波的信息量显著增加，可为实现结构的安全性和可靠性评估提供有力支撑，是复合材料损伤检测的一个前沿科学问题。课题围绕复合材料的宽带导波损伤检测开展研究，从宽带导波的信息理解入手，通过导波模态分离，消除背景信号，揭示结构损伤与导波信息关联的内在机制。在此基础上，建立模态频散规律的时频映射及多参匹配模型，实现损伤特征的辨识与溯源。进一步，研究宽带导波的故障信息挖掘技术，建立对缺陷敏感的特征指标集，并揭示指标集随损伤类型和程度的演化规律，为复合材料结构的损伤检测与状态评估奠定理论和方法基础。本课题的研究工作可为在役复合材料结构的状态评估、健康维护和有效管理提供可靠的依据。

随着复合材料在航空、能源、船舶等领域高端装备中应用量的迅猛增长，其损伤检测与评估已成为这些装备安全、可靠运行的迫切需求。相比窄带导波，宽带导波的信息量显著增加，可为实现结构的安全性和可靠性评估提供有力支撑，是复合材料损伤检测的一个前沿科学问题。项目围绕复合材料的宽带导波损伤检测开展研究，从宽带导波的信息理解入手，建立了联合时频域和波数-频率域导波模态分离方法，消除了背景信号的影响，揭示了结构损伤与导波信息关联的内在机制。在此基础上，建立了基于激励信号重塑与时空域映射的频散补偿方法，实现了损伤特征的辨识与溯源。进一步，提出了基于互异性原理的无基准损伤检测方法，有效提升了复合材料结构在线健康监测的环境鲁棒性；建立了复合材料损伤轮廓重构与评估算法，实现了损伤评价由定性诊断到定量评估的跨越。本项目的研究建立了激励信号波形优化、信号频散补偿、脉冲压缩、稀疏重构等一系列模型和策略，显著提高了超声导波复合材料损伤检测的稳定性和可靠性，为实现复合材料层合板的高分辨损伤检测提供了新思路。在本领域权威期刊发表SCI论文16篇；申请国家发明专利5项（其中3项已获得授权），为在役复合材料结构的状态评估、健康维护和有效管理奠定了理论和方法基础。