Error Sensibility Analysis Of Finite Element Model Of Concrete Filled Steel Tubular Arch Bridge

As a kind of widely used bridge in the past two decades, Concrete Filled Steel Tubular Arch Bridges make the best use of the advantages of steel tubular and concrete material combines, such as high compressive strength, good ductility. Because of complexity in both design and construction, research on this new kind of bridge is drawing more and more attention. With the developing in computer technology, using finite element software to create a model for calculation and analysis became one of the main study method, which is applied in bridge design comparison, health diagnosis and damage identification. Establishment of structure model is the foundation and key of calculation and study, analyzing and controlling the error of finite element model to obtain high-accuracy finite element model, it is very important to structure simulation, damage identification and health diagnosis.According to the existing concrete-filled steel tubular arch bridge data, ANSYS finite element software is used to built the initial model of three-Span concrete-filled steel tubular arch bridge, calculate the dynamic and static response value of initial model as the basic compare parameters. Change a modeling factor to get a new model based on the initial model, change of dynamic and static response value between new model and initial model is compared. Impact of different modeling factors to local dynamic and static response value of model is researched, sensitivity of each dynamic and static response error to different modeling factors is summarized. The main modeling factors are the synergy of steel tubular and concrete, influence of concrete separation in steel tubular, compare between single span and more-span, influence of left and right arch rib lateral ties. The main dynamic and static response are deformation and internal force of arch rib under constant load, deformation and internal force of arch rib under load, internal force of derrick, Frequency and modal.Two methods are adopted in the paper to simulate the cooperative action between steel tubular and concrete, which is transformed cross section and improving the strength grade of concrete, impact of mutual action between steel tubular and concrete to dynamic and static response value of model is calculated, the model which consider the mutual action between steel tubular and concrete has high sensitivity in arch rib deformation, internal force change of arch rib and derrick. The way taking concrete separation section instead of initial model section to simulate the concrete separation was adopted, calculate each dynamic and static response of different concrete separation model, concrete separation model has high sensitivity in arch rib deformation, internal force change of arch rib and derrick. The difference of dynamic and static response between single span and more-span was compared, single span model has high sensitivity in arch rib deformation, internal force change of arch rib and derrick. The way lowing lateral brace rigidity was adopted, calculate each dynamic and static response of different lateral brace rigidity model, low lateral brace rigidity model has high sensitivity in arch rib deformation, internal force change of arch rib and derrick. The sensitivity of various modeling factors was summarized to build the finite element model comprehensively and holistically.