基于热波成像的复合材料低速冲击损伤表征、识别与扩展演化规律研究

Holding the dynamic characteristics of high non-linearity, multiple scales and complex deformations, the low-velocity impact damage of composite material brings serious hidden security dangers to the aero-crafts. This work aims to explore the basic theories and common technologies of the rapid detection, characterization, recognition, extending evolution rule prediction and fatigue performance evaluation of the composite material impact damage performed by the thermal wave imaging technique. Firstly, a mechanical-thermal coupling model able to describe the destroy mechanism and transient thermal conduction of low-velocity impact in the composite material structure is proposed and the intrinsic connections between the impact damage parameters (the pit depth, area, etc.) , damage expansion law and transient surface heat wave characteristics are investigated. Then, a kind of thermal wave imaging detection theories and evaluation methods which can optimize the comprehensive performance involving thermal excitation of accurate control, transient thermal wave uniform coating, thermograph sequence high-speed reconstruction and processing, rapid detection of damage as well as parameter quantitative recognition in the global manner are constructed to realize the complete carrying, effective characterization and high fidelity interpretation of the impact damage information. Thirdly, a prediction method of the impact damage evolution rules is investigated on the transient thermal wave characteristics of composite materials and a theoretical foundation for the fatigue performance evaluation of composite material is established. The research findings will provide new and efficient nondestructive detection theories and evaluation methods for the impact damage of aircraft composite structure, with strong theoretical significance and engineering application values.

复合材料低速冲击损伤具有高度的“非线性、多尺度、复杂变形”等动力学特性，给飞行器带来严重的安全隐患。项目旨在探索基于热波成像的复合材料冲击损伤快速检测、表征识别、扩展演化规律预测和疲劳性能评估等基础理论和共性技术难题：建立复合材料结构低速冲击破坏机理与瞬态热波传导的力-热耦合模型，探索冲击损伤参数（凹坑深度、面积等）、损伤扩展规律与表面瞬态热波特征之间的内在关联，构建具有热激励源精确控制、瞬态热波均匀覆盖、热图序列高速重建和处理、损伤快速检测和参数定量识别等综合性能全局优化的热波成像检测理论和评估方法，实现冲击损伤信息的完整携带、有效表征和高保真解读。以此为基础，探索基于表面瞬态热波特征的复合材料冲击损伤扩展演化规律预测方法，为实现冲击后复合材料结构的疲劳性能评估奠定理论基础。研究成果将为飞行器复合材料结构冲击损伤提供一种新型高效的无损检测理论和评价方法，具有较强的理论意义和工程应用价值。

本项目将红外热波成像技术应用于复合材料的低速冲击损伤表征、识别与扩展演化规律研究，通过对复合材料层合结构低速冲击破坏及瞬态热波传导的力-热耦合机理的研究，建立了纤维断裂、基体开裂、分层等典型冲击损伤的热波成像检测理论。重点研究了基于热图序列处理和分析的典型冲击损伤模式表征和参数识别方法，解决了热波成像技术因受制于硬件设备的限制，以及各种不利影响因素的干扰而存在的热图序列数据量大、缺陷定量判别难等问题，实现了冲击损伤的定量识别，为损伤扩展演化规律研究提供了方法支持。通过研究复合材料在冲击载荷、疲劳载荷过程中的能量变化和损伤扩展演化规律，建立了表面瞬态热波特征与含冲击损伤复合材料结构疲劳性能之间的定量关系模型，实现了基于热波成像的复合材料冲击损伤扩展演化规律预测。通过上述研究，提出了一套完整的基于热波成像技术的复合材料低速冲击损伤检测、表征、识别、损伤扩展演化规律预测理论和方法。项目研究为含损伤复合材料剩余疲劳性能评估奠定了理论基础，同时也推动了我国热波成像技术由无损检测向无损评价阶段发展，具有较强的理论意义和工程应用价值，经济、社会和军事效益显著。