Hull Structure Damage Identification Based On Fuzz Mode Identification Technique

Structures have always injure, such as split in beam, post, plank and hull, etc; weld in steel structures; detonation of pressure container and so on. But damage emergence frequency and degree of these structures are littler than that of machines. Because it is permited that structures work with damage(such as concrete construction), at the moment the structures examination technique is always belong to assessing the dependable degree of structures and development of the structures damage identification technique is not consummate. Lately because of the frequently abrupt event and the emergence of high-rise, expressway, railroad and great strech bridge that are damaged being to create hugely economical loss, the technique of structures damage identification more and more becomes a international research heatpoint.Just as the previous illustration, although the technique of structures damage identification is more and more discussed, it's development is not consummate as a new research territory and research literatures about this technique are few at the moment. This paper proposes some new methods about damage identification technique. I hope these methods are helpful to those people who research damage identification technique. The abstract of this paper is as follows.The issue on identifying hull structure damage is investigated intensively in present paper, by using fuzzy mode identification method and referencing the related theory on strain mode analysis. Strain mode parameter and mode identification theory originate from mechanical engineering territory. They are used to structure engineering lately. Strain mode is similar to move mode that we know intimately. Because the transformation relationship between strain mode and move mode is same as the transformation relationship between strain and move, we can get strain mode of construction by move mode. Because strain parameter is more sensitive to structural local minute manage, we use strain mode to identify structure damage in this paper. On the other hand, it is hardly found that researcher identify structure damage by using fuzzy mode identification method. I attempt to identify hull structure damage by using fuzzy mode identification method in this paper. I hope this paper can propose some new idea for structures damage identification technique.The main content of the paper is as follows:(1) Various damage identification technique is introduced briefly in home and abroad. It is pointed out that compared to damage identificationtechnique based on vibrational parameter the traditional damage identification technique has some shortcoming that it can not accurately identify construction damage location and degree.(2) The sphere of application on various structural damage identification parameter based on vibrational feature is presented. It is pointed that the strain parameter is more sensitive to structural local minute damage than other sorts of parameter, so it is very ideal parameter for structural damage identification. At the same time, strain mode 's character is stressly analysed. A method of measuring strain mode is proposed.(3) The primary theory of using finite element method to analyse hull construction is illustrated. What how to establish hull element strain matrix, stiffness matrix and quality matrix is stressly introduced. Then the finite element program of the plank structure rectangle element and the hull structure rectangle and delta composite element is composed based on finite element theory by Fortran language. These settle base for getting hull structure's strain mode.(4) Some related information on mode identification technique is introduced briefly. It is pointed out that mode identification method can be divided into statistics mode identification method, sentence structure mode identification method, fuzz mode identification method and neural networks mode identification method. Fuzz mode identification technique is stressly illustrated. It is pointed out fuzz mode identification method can be divided...