基于超声动态响应分析技术的点阵夹芯板损伤识别与结构健康监测方法研究

As one typical kind of multifunctional structure materials with high porosity, novel lattice sandwich plate, which has advantages of light weight, high strength, high heat insulation etc., now has received more and more attention from aerospace, navigation and other industry field. However, in order to analysis variety damages of the inevitable defects in lattice structures, ensure the safety of the structure, and prevent catastrophes, it has important application value and practical significance of the establishment of damage identification and structural health monitoring system for lattice structures. This project aims at detecting the typical damage defects in lattice sandwich plates. By combining of numerical simulation and experimental research, global and local ultrasonic vibration and ultrasonic guided wave propagation principle will be analyzed quantitatively. Meanwhile, the damage identification and structural health monitoring system will be established for lattice sandwich plates, based on the influence of the defects on the ultrasonic vibration and guide wave propagation response..This research can solve the damage detection and structural health monitoring problem for lattice sandwich plates, which now is limited by the shortage of the ultrasonic vibration response and ultrasonic guided wave propagation characteristics that can lead to imprecision of damage locating and difficult to detect small defects. This technology can improve the damage identification and imaging precision, and then to establish the structural health monitoring system for lattice sandwich plates.

作为新颖的多功能结构型材料—点阵夹芯板，其高孔隙率使之具有轻质、高强、高效散热等特性，越来越受到航空航天、舰船等诸多领域的关注。然而为了应对点阵夹芯板中不可避免的损伤缺陷，保证结构安全使用，建立损伤识别与结构健康监测系统具有重要的应用价值和实际工程意义。本项目拟针对点阵夹芯板中典型损伤缺陷，结合数值模拟与实验研究，采用超声动态响应检测技术，定量分析被测结构超声振动响应以及导波传播特性的规律，并根据结构中各类典型损伤对超声动态响应参数的影响，实现点阵夹芯板中的损伤定位识别，提出针对点阵夹芯板的结构健康监测方案。.本项目的研究可解决目前针对点阵夹芯板损伤检测中，由于超声振动响应及超声导波传播特性研究的缺乏，导致损伤识别的精度较低，难以对微小损伤检测的不足。采用本项目中提出的超声频段动态响应分析技术可以进一步提高点阵夹芯板中的损伤定位识别与成像精度，进而可构建适用于点阵夹芯板的结构健康监测系统。

点阵夹芯结构作为一种新型工程材料，被广泛的运用于各个工业领域。点阵夹芯结构因其内部结构设计的复杂性，在工艺制备及使用过程中会发生单胞缺损或焊点脱焊等各类损伤，亟需快速有效可靠的检测技术以确保结构的安全性。针对点阵夹芯结构的脱焊等损伤问题，本项目提出了基于高频动态响应的损伤检测方法。以分析得出的损伤区域局部共振频率为中心，择取宽频带的间歇周期性四峰波稳态激励信号，综合考虑结构在多个频率下的动态响应，运用本项目提出的损伤指标，实现了点阵夹芯结构内部损伤的快速识别定位。在实验研究方面，为了提高检测效率，减小测量设备对结构的影响，本项目提出了采用扬声器声场激励，扫描式激光测振系统进行全场振型拾取的非接触式的检测方案，实现了无附加结构质量、无健康基准信号下的损伤识别，为结构的在役监测提供了新的方法和理论依据。.本项目的研究促进了无损检测与结构健康监测评估技术的发展，对实现复杂结构智能化结构健康监测系统的实际应用具有重要意义。