基于模态应变能方法功能梯度材料梁式结构损伤识别的研究

项目名称： 基于模态应变能方法功能梯度材料梁式结构损伤识别的研究

项目编号： No.11262002

项目类型： 地区科学基金项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 黄立新

作者单位： 广西大学

项目金额： 36万元

中文摘要： 功能梯度材料是一种材料性能连续变化的新型非均匀复合材料。作为工程中很重要的构件，功能梯度材料梁式结构在航空航天、土木工程等领域有独特的应用。该类结构损伤时，会影响整体结构的安全性能。没有注意到损伤发生并不断累积的情况，而继续使用这类结构，最终会导致结构失效，造成重大损失。因此，功能梯度材料梁式结构损伤识别已成为其应用的必然要求。模态应变能损伤识别方法在局部损伤的敏感度、识别损伤的程度、稳定性和抗噪音等方面有优势。本项目拟进行基于模态应变能方法功能梯度材料梁式结构损伤识别的研究。基于高阶剪切变形梁理论，建立功能梯度材料梁式结构动力分析的高精度有限元数值模型。在此基础上，基于模态应变能方法提出结构损伤识别的高敏感度量化指标。引入损伤量化指标的统计概率，研究结构损伤识别和虚警(false alarm)的统计概率问题，减少损伤误报率和漏报率，并探讨模型误差、噪音，振型阶数等因素对识别结果的影响。

中文关键词： 功能梯度材料；模态应变能；梁式结构；有限元法；损伤识别

英文摘要： Functionally graded material(FGM) is a new kind of inhomogeneous composite materials with the continuously varying material property in space. As a very improtant structural component in engineering, FGM beam-like structures have been increasingly used in many fields, such as aerospace, civil engineering, etc.,due to their unique graded feature. Damage in the FGM beam-like structures will reduce the system safty performance. Without finding the accumulating continually damage in such strucutres during their service life, there probably occurs a catastrophic structural failure, which will result in heavy losses. Therefore, it is inevitable to identify the damage in the FGM beam-like structures for FGM application in modern engineering. Damage identification method which is based on modal strain energy has superior in many respects such as the sensitivity to local defects, severity estimation, stability and noise resistance ability. This project intends to study the damage identification of FGM beam-like structures based on modal strain energy method. A finite element model with higher accuracy will be developed for the dynamic analysis of FGM beam-like structures by considering the higher-order shear deformation beam theory. On the basis of the hihger-accuracy finite element model, hypersensitivity indicators for

英文关键词： Functionally graded material；modal strain energy；beam-like structure；finite element method；damage identification