Research On Damage Identification Of The Beam Structural Based On The Wavelet Analysis And The Moving Mass Method

With the improvement of science and technology, engineering structure has development to maximization, complication and light. However, materials will become deterioration and fatigue damage when structure in complicated environment, which will cause disastrous consequences, not only threatening people's lives and security, but also bringing about enormous losses of social wealth. The method of wavelet analysis has unique advantages in feature extraction, the singularity of signal detection, and signal de-noising. Therefore, it is great significant theoretically and practically to use the method of wavelet analysis to identify the structural damage.According to plenty of professional literatures about the identification of the damage in engineering structures home and abroad, the paper has summed up the current situation and the method of the structural damage identification .The single and multiple damage sites were identificated accurately in the simply supported beam and cantilever beam with homogeneous material or not, by using the improved method of the moving quality repetitious detection ,firstly integrating with the method of wavelet analysis .At last the paper has studied the method of the lacking dynamic signature in the girder structure and established the following conclusions:(1)There is practicality of the improved method of the moving quality repetitious detection to identify the detection of the engineering structures. The quality, one of the physical parameters in the structure, is constantly changeable and controlled easily. The frequency parameter can also be measured simply in the vibrate test to analyze the detection of the structure.(2) The relative rate curve of natural frequency which produced by the moving mass position change will be slightly altered because of the existed of the damage in the structure .With the method of the wavelet decomposition the singular point can be distinguished accurately.(3) The improved method of the moving quality repetitious detection integrated with the method of wavelet analysis will get widely application in the detection of the damage in engineering structures. As shown in the paper, the single and multiple damages in the structure were checked evidently, especially for the constant section beam or the inconstant ones with homogeneous material or not, the new method has been suitable for use greatly. Besides, it can also be applied in the detection of the homogeneous material and constant section beam which lack dynamic signature.(4) The local damage of the structure is more sensitive to the higher level signals than the lower ones. In regularly, the multiple sites of the damage can be identified by measuring one of the higher levels.