Damage Identification Of Truss Bridge

With the continuous development of our economy,accelerating urbanization process,in order to alleviate the increasing traffic pressure,in addition to need a lot of new Bridges,it is must to reinforce the existing Bridges and infrastructure.Bridges in service in the process will be under the action of various factors,accumulate gradually formed certain damage,the damage is often difficult to observed with the naked eye,the hidden damage will bring risk to life safety and property safety.Therefore,for the damage detection of bridge structure recognition is realistic.At present,the bridge structure damage identification has attracted worldwide attention,the recognition method is numerous,but are also more drawbacks,there are great development space.Due to the complexity of bridge structure by internal and the joint of the external environment factors,make the damage with a single method is difficult to completely state the bridge for accurate positioning and quantitative analysis.And some of the high precision of bridge structure damage identification method,such as vibration based on branch is mainly confined to theoretical analysis and simulation experiment,has yet to be directly used in practical engineering.So the high performance,high standards of recognition method has become a new field in the study of science and technology all over the world.Bridges in addition to outside the damage accumulates in the process of service,in the war(including preventing terrorist attacks),facilities tend to be attacked first,and be devastating.In view of this special situation,in many parts of the damaged bridge damage to the extent of rapid identification,fast and efficient repair,to quickly recover and improve the strategic materials of bridge bearing means of research in the field of apparently also has very important value.This paper introduces several relatively mature at home and abroad,based on the parameters of the bridge structure damage identification methods,the advantages and disadvantages of various identification methods are summarized,and the detection of damage identification method for this article,based on the natural frequency of bridge structural damage detection identification methods are studied and analyzed,the concrete research content is summed up in the following:(1)Study inherent frequency idea of damage identification methods,the theory of all kinds of damage identification analysis thought in the form of a calculation formula to implement,in order to achieve the purpose of damage identification.(2)Based on the damage identification method and the static displacement analysis method based on the natural frequency,the finite element software MIDAS is used to analyze the model of the truss bridge.The different modal frequencies of the bridge model under different damage conditions and different loading forces are calculated by the method of concentrated loading force,and the direct damage identification of the bridge structure is carried out.(3)According to the results of the finite element analysis,model for the concrete-filled truss bridge entity bridge model is established,the specific test methods according to the recognition in strict accordance with the steps.(4)In the process of finite element simulation and physical model test,the bridge structure is on the static damage simulation and static load damage identification,comparing its MIDAS software simulation of natural frequency test results of damage detection identification method.Finally,summarize the problems that should be paid attention to in the process of simulation and experiment,In the process of finite element simulation and physical model test were analyzed among the damage simulation realization method,and the simulation method in the implementation process is likely to be above simulation of the impact of the effect.On the basis of simulation analysis and physical model test,this paper implements the methods of damage identification based on the inherent frequency in the application of the finite element simulation and engineering example.