The Research On Damage Identification Of Concrete Cantilever Beam Based On Vibration Mode

In order to ensure the safety of the structure,we should fully understand the damage status and bearing capacity changes of the structure during its service period,so that the damage accumulation can be detected before it reaches the level of threatening the safety of the structure.Accurate identification of structural damage and correct evaluation of the working state of structures are not only related to the safe use of engineering structures,but also important for deciding whether and when to carry out maintenance and reinforcement.In service based on the engineering background of cantilever beam structure damage detection,based on the beam vibration mechanics theory,the theoretical analysis,numerical simulation and experimental research on the way of combining basic component of cantilever beam structure of engineering structure damage identification problem carried on the thorough analysis and research,the main research content is as follows:(1)This paper summarizes the background of structural health monitoring and its practical engineering significance,summarizes the existing research progress of damage identification methods at home and abroad,and briefly introduces the application and development of wavelet analysis.(2)According to Euler-Bernoulli beam theory,the bending vibration of cantilever beam is studied theoretically,the natural frequency of cantilever beam is obtained,and the curvature mode theory is introduced.Finally,the theory of wavelet transform is introduced.(3)Taking 1.5m and 2m concrete cantilever beams with different damage positions as examples,the damage identification experiment of PSV vibration test system under the action of shaker is completed.Introduces the vibration modal parameter identification method under the system,including prophase PSV software of the system parameter setting and operation steps,data acquisition method,crack load,get natural frequency of the cantilever beam,various order vibration mode such as modal data,and USES the curvature modal method for damage location identification,verify the vibrator vibration under the action of SLDV testing system of continuous scanning laser test method and the feasibility of curvature modal method of damage identification.(4)Finite element software ABAQUS was used to model cantilever beams with different damage positions and damage degrees,and different modeling methods were used to analyze different damage conditions.After completion of the simulation calculation for each order modal parameters,analysis of health and the damage beam of each order natural frequency and modal vibration mode,and the vibration mode of experiments and finite element simulation of a data respectively using curvature mode and the theory of wavelet transform were analyzed,and further compared the result of data processing,complete,for identifying the damage location to verify the effectiveness of the two methods.