The Studies On Damage Detection Methods In Structure Based On Vibration Monitoring

This paper summarizes the significance,present situation and developing process of structural health monitoring and damage detection. Global damage detection method based on vibration monitoring is a research hotspot currently. These damage detection methods are dissertated roundly as well as their advantages and disadvantages.As we known,modal shapes identified under ambient excitation can not be mass-normalized; high modal parameter is difficult to be excited under operational conditions; the structural rotational degree of freedoms can not be measured in dynamic tests. To avoid these limitations of the factors mentioned above, this paper systematically studies damage detection methods based on modal strain energy and summarizes the present situation of them in both home and abroad, the method to detect complex structural damage is proposed on the basis of the existing methods. The major advantages associated with the new method are that minimal measured modal information is required—only making use of pre- and post-damage modal natural frequencies and shapes that are available for only a few modes of vibration . Additionally, the new method does not require the mass-normalized modes and testing information of rotational degree of freedoms. First, numerical studies of three-dimensional frame structure, Benchmark structure and offshore platform structure based on modal parameters generated from finite element models are carried out. Next, the new method is testified again with an offshore platform physical model. According to the results, the proposed method is shown to be effective for the complex structural damage detection and has wide application prospect。...