Research On Structural Damage Identification Based On Vibration Characteristics

Due to the influence of various factors in the use environment during the service period,the engineering structure will inevitably cause structural damage in different degrees.When the damage accumulates to a certain extent,it may cause major safety accidents and cause serious losses to human life and property.Therefore,in order to carry out health monitoring and safety assessment of the engineering structure to ensure its safety and reliability,research and development of an accurate and efficient method of structural damage identification has extremely important social realistic significance.It is a hot area that experts and scholars are concerned about today.In this paper,the research background and significance of the current structural damage identification method based on vibration characteristics and the research status at home and abroad are described.The research and development status of the structural damage identification method based on the element modal strain energy and frequency response function are emphasized.The main research content of this article.Secondly,from the basic theory of finite element,the expression of the element modal strain energy of Euler-Bernoulli beam element is deduced.Then the structural damage identification method based on element modal strain energy is studied in detail.Through the numerical simulation of a simple supported beam example,the damage location of the structure is accurately determined by using the modal strain energy damage index,and the feasibility and effectiveness of the damage location identification method are verified.Thirdly,on the basis of realizing the structure damage location,because the frequency response function contains more abundant structural dynamic characteristics information,it is easy to obtain directly through the test and the error is relatively small,there is a certain anti-noise performance,etc.,so we have chosen a Quantitative structural damage identification method based on frequency response function continues to conduct in-depth research on structural damage assessment.Still using the numerical simulation of the simple support beam example,using thefrequency-frequency function damage index of the structure,the damage degree of the damage unit was accurately calculated by the damage quantitative calculation formula,and the feasibility and effectiveness of the quantitative identification method of the damage were verified.Finally,through the numerical simulation of a plane five-story frame structure,the structural damage is characterized by the reduction of element stiffness,and the structural damage diagnosis under six different damage conditions including single damage and mixed damage at different positions of the beam column is studied.The numerical simulation results show that the unit modal strain energy damage identification index can better achieve the damage location of single or multiple damage,and with the increase of the damage degree,the accuracy of the damage location is gradually improved,and the low-order mode is easier The existence of the damage location is identified;and the frequency-following function damage identification index can precisely realize the damage quantification of single or multiple damages,and the quantitative identification result of the method can be satisfied if the actual damage number of the structure is not too large.Accuracy.The numerical simulation results fully show that the exploratory study of structural damage diagnosis combined with modal strain energy and frequency response function of the unit is accurate and effective,and the advantages and advantages of structural damage identification are improved by using both advantages.Real-time health monitoring provides a certain theoretical basis,and it is hoped that relevant research can help engineering practice.