Research On Damage Identification Of Ship Structure Based On Vibration Information

Ships and Marine structures have long served in the Marine environment,the complex and harsh sea conditions will cause corrosion and aging of the structure until damage occurs,therefore,damage identification has important theoretical significance and engineering application value for ensuring the safe operation of structures.Structural damage identification based on vibration information has attracted attention due to its features such as saving manpower and material resources,simple testing and on-line real-time monitoring.The main content of this paper is to study the damage identification based on the time-domain feature analysis technology of structural vibration signals on the basis of learning damage identification eigenvalue method and vibration signal processing theory.Specific study as follows:1.Research on eigenvalue method of damage identification based on vibration response time domain signal.Based on the vibration time domain signal before and after structural damage,Damage identification is based on the mean curvature difference method and the curvature difference probability method,the fractal dimension is used as the eigenvalue of damage identification,the mean value of curvature difference and curvature probability before and after injury is used as the index of damage identification,and the recognition effect at different noise levels is studied.The method combines the advantages of several mathematical tools,and got periodic results.2.Based on vibration signal processing,the damage identification method is proposed to study the micro damage identification ability.Wavelet denoising,empirical mode decomposition(EMD)and intrinsic time scale decomposition(ITD)are applied to deal with vibration signals.Based on the processed signal,the fractal dimension curvature difference method and curvature difference probability method are used to identify the minor damage of structures,and beneficial results are obtained.In this paper,the structural vibration signal is used to identify the damage.The anti noise performance of the method and the recognition ability of the method for small damage are explored,and the technical support is provided for the damage identification and health monitoring of the ship structure.