基于动力学特性的金属点阵夹层板损伤识别方法研究

Damage identification of metallic sandwich panel with truss cores is very important to the early damage discovery, residual life assessment, structural maintenance and accident reset for future high-speed flight. This project aims to develop damage identification method for sandwich panel with truss cores based on their dynamic properties. Through systemic experimental approach and analytical method, the influences of damage features (style, location and extent) to its dynamic properties will be presented, and the trends of the influences for different structural geometries will be revealed. In addition, the sensitivities of dynamic parameters to damage will be obtained, and their trend charts for different structural geometries also will be provided. Based on the above analytical results, damage indexes will be presented, and the damage identification methods for different damage features will be proposed. Meanwhile, experimental method to capture detailed structural complicated modes will be developed relied on 3D laser Doppler velocimeter. The significances of the project is to make some progress in theoretical analysis and experimental technique in damage identification of truss core sandwich, and propel the application of this novel light-weight structure in the thermal protection systems in aerospace technology.

金属点阵夹层板损伤识别研究，对于未来飞行器结构的早期损伤预报、剩余寿命评估、结构维护、事故归零等都具有重要意义。本项目针对金属点阵夹层板开展基于动力学特性的损伤识别方法研究。旨在揭示不同损伤特征（类型、位置、程度）对点阵夹层板动力学特性的影响机制与规律，获得不同几何参数条件下影响规律的变化趋势。开展不同动力学参数的损伤敏感性分析，绘制动力学参数损伤敏感性的趋势图谱。在此基础上，提出损伤敏感标识量，发展针对不同损伤特征的识别方法。同时，本项目还将重点发展基于三维激光测振技术的点阵夹层板复杂动力学特性的精细捕捉试验方法。研究成果有望推进点阵夹层板损伤识别理论与测试技术的发展，促进这类新型轻质结构在航天热防护领域的应用。

金属点阵夹层板热防护结构的损伤识别对于实现飞行器事故归零、结构维护、剩余寿命评估等至关重要。本项目针对金属点阵夹层板开展基于动力学特性的损伤识别方法研究。首先，通过理论分析与数值模拟，获得不同形式的损伤特征（位置/程度/分布）与约束条件等因素对点阵夹层板动力学特性的影响规律与机制。其次，基于前面分析，提出一种无基线的点阵夹层板损伤反演方法，可实现在无结构完好信息对比的情况下，仅根据结构当前信息便可对结构内部损伤进行反演。此外，还提出一种基于时域响应的点阵夹层板损伤反演方法，利用时域响应信息的丰富/多样性，可对结构内部损伤进行有效反演。本项目发展的两种方法均可实现结构内部损伤位置与程度识别。最后，开展基于三维激光测振的点阵夹层板实验。实验结果表明，提出的两种方法可以很好的识别实际点阵夹层板结构内部的损伤，具有在实际工程中的应用潜力。这些方法的提出对于促进点阵夹层板结构在工程结构的实际应用，以及服役过程中的在线监测提供很好的思路。