DEVELOPMENT OF NEW NDT SYSTEMS BASED ON KALMAN-FILTER BOUNDARY ELEMENT METHOD

本研究项目旨在开发基于卡尔曼滤波理论的直接分析方法的新型无损检测系统。作为本课题的基础技术，我们开发了势场、弹性静力场、热弹性场、弹性动力场的反分析程序。在此基础上，我们尝试应用弹性动力学和温度场的反分析方法，开发新的无损检测系统。在弹性动力学反问题中，稳态和非稳态响应被用来作为附加信息，并尝试采用滤波理论，如卡尔曼或投影滤波，以提高反分析方法的鲁棒性。并将逆分析方法成功地应用于振动和温度场的主动控制。本文的主要研究成果如下：（1）发展了二维弹性动力学稳态响应和非稳态响应的反分析方法。在实际问题中，采用了卡尔曼滤波和投影滤波，证明投影滤波对提高反演分析的鲁棒性更为有效。（2）对声学和弹性动力学问题提出了非常精确的灵敏度分析方法，并将其应用于相应的反问题。（3）发展了稳态和非稳态温度场的模拟技术。（4）三维问题的实际应用，所取得的一些成果已经作为论文发表在著名的学术期刊上，而其他一些成果正在考虑向这些期刊投稿。因此，可以得出结论，大部分的研究项目已经完成了本项目的期限。

This research project aims at development of new non-destructive testing systems based on a direct analysis method using Kalman filter theory. As fundamental techniques of this research project, we have developed some of inverse analysis procedures for potential, elastostatic, thermoelastic, elastodynamic fields. Then, we have tried to develop new non-destructive testing systems by applying the inverse ananlysis methods for elastodynamic and temperature firlds. In the elastodynamic inverse problems, steady and non-steady responses were used for additional information, and attempt was also made to employ the filter theory such as Kalman or projection filter to improve the robustness of the inverse ananlysis methods. Furthermore, the inverse analysis methods developed were successfully applied to active control of vibration and temperature fields. We may summarize the results obtained in this research project as follows :(1)Inverse analysis methods were developed by using steady or non-steady responses in two-dimensional elastodynamics. Use was made of the Kalman filter and the projection filter for some of the practical problems, whereby the projection filter is more efective for improvement of the robustness of inverse analysis.(2)Very accurate methods of sensitivity analysis were developed for acoustic and elastodynamic problems, and then they were applied tu the corresponding inverse problems.(3)New simulation techniques were developed for steady and non-steady temperature fields.(4)Application is being made to three-dimensional problems in practice.Some of the results obtained have been already reported as contributed papers which appeared in prominent, academic journals, while several others are being considered to contribute to such journals. Therefore, it can be concluded that most of the research project has been accomplished in the term of this project.