The Reseaach On The Bridge Structural Damage Identification Based On Compliance Coefficient

As a hub of the road transportation network,the bridge occupies an important position.The bridge affected by unfavorable factors such as the aging of materials,load effect and harsh environments in the operation process,this will cause varying degrees of damage.With the accumulation of damage,the bridge structure has a big security risk,and constitutes a serious threat to the lives and property of the masses and social stability.So it is of great significance to use the health monitoring system,identifying accurately and effectively on bridge structures damage,establishing a connection with the residual bearing capacity and finding a practical,efficient,and accurate way to damage identification.In this paper,the beam model and the actual bridge project play the role of research object,combining with structural dynamics,nonlinear finite element theory,matrix theory,real bridge field test and other research tools to research,and then complete the following studies:1 ? This paper summarizes the current situation and development trend of structural damage,analysis the methods of bridge structure damage identification.It compares the advantages and disadvantages and applications of various damage identification methods,it also does further study of bridge structure damage identification and bearing capacity evaluation provides a theoretical basis.2 ? This paper defined the structure's overall damage coefficient with overall flexibility coefficient of the rate of change before and after the structural damage.And beam with 2d as the research object,it also analyzed the structure mass distribution,impact damage location,modal order and the number of measurement points and other uncertain factors on the structure of the overall flexibility coefficient.3?In six meters of reinforced concrete beams for the object,this paper carried out the entire process of reinforced concrete beams nonlinear finite element analysis from intact to destroy by the using nonlinear finite element software ADINA.It selected seven kinds of simulate damage cases about reinforced concrete beams to obtain the modal parameters of various damage conditions with ADINA's restart function,and then built flexibility matrix and calculate the structure's overall flexibility coefficient and the structure's overall damagecoefficient,at last,we can get seven kinds of damage cases of the remaining bearing capacity of the structure.It also verified the method of feasibility,effectiveness and accuracy.4?his paper conducted a modal test on the reinforced concrete solid bridge based on environment excitation,and then using MATLAB software to quality normalized the results,we can got real bridge quality normalized natural frequencies and mode shapes,and then got overall flexibility coefficient which can reflect a real bridge's characters this time.5?This paper established a fine finite element model of reinforced concrete bridge,and it is defined as a baseline finite element model by using ADINA.By simulating different damage working conditions,we calculated a graph between the overall damage coefficient and capacity of the real bridge.Thus it can be found in the overall damage coefficient and residual bearing capacity.so it can be detected on the bridge,provide a theoretical basis for the bridge maintenance reinforcement.