A Study On The Method Based On Vibration Of Damage Identification Of Structures

Damage occurs sometimes in structures in the form of cracks. The fact that crack occurs, determines the reliability and security of structures to some extent. For this reason, it is very important to analyze the vibration characteristics and to identify the damage of cracked structures.Firstly, a summary of current global nondestructive damage identification technology for structures is given in this thesis. This article evaluated"partial non-destructive identification method, based on structural static test of the damage identification methods, based on structural dynamic test of the damage identification methods, intelligent diagnostics", which are four of today's primary methods of damage identification. This article also introduced the research progress of crack models.Secondly, the paper used to the rotational spring model to study the dynamic characteristics of cracked beam; derived cracked beam bending free vibration equation; by vibration differential equations, crack deformation equation is derived by the concept of mobility.Then, applying the theory to solve the cantilever beam and simply supported simple beam structure of the integrity and the cracked state analytical solution. Analysis of the crack location and depth of the change on the impact of the natural frequencies derived cracked beam structure of the free vibration equation based on the"point of intersection curves of the characteristic equation method". Application of finite element analysis software ANSYS for modeling three-dimensional cracked beam by finite element analysis of space has been simulation of the modal parameters of its data, in accordance with the method proposed in this paper to identify the crack location and depth.Simply supported beam due to the existence of symmetry in the identification process is not the only solution in this paper using wavelet analysis, respectively, and added mass method to solve simple to identify when the use of the natural frequency of the identification results usually are not the only problem. In this paper, the damage identification of multiple cracks on the cantilever beam is discussed.Finally, the above method to the complex structure, for the continuous beam, semi-rigid frame structure, the application of"point of intersection curves of the characteristic equation method", a two-stage study of damage identification methods is used and accurately identify the structural damage state.