Nonlinear Finte Element Analysis Of PC Box Girder

Modern long-span concrete box girder bridges are powered by prestressed concrete structures. Up to now, the research of this kind Concrete box girder is not perfect.Therefore, it is necessary to do the more further research to spatial bearing behavior analysis on prestressed concrete box girder. Based on ANSYS platform, this paper carries out finite element analysis on the prestressed concrete box girder, and completes for the following aspects:(1) The latest research status on the concrete structure are system summarized, including non-linear analysis of concrete structures, box capacity and the shear lag; The basic principles of finite element method is briefly described, The basic steps of the finite element method are concluded, Then the non-linear theory and nonlinear equations and convergence are summarized, and the paper discusses the prestressed concrete box beam finite element analysis theory and its implementation in ANSYS.(2) Based on ANSYS platform,the whole process in the corresponding load conditions is simulated from the load to damage for the existing prestressed concrete box girder, Through the establishment of prestressed concrete box beam finite element model. with the comparative analysis to test results, The reliability of the finite element model and nonlinear analysis of the feasibility are verified.(3) More detailed study on the important parameters of the carrying capacity of prestressed concrete box is conducted, These parameters include the thickness of roof box girder, prestressed reinforced area, concrete strength and the effective prestressing, the displacement-load deflection curve, limited deflection and ultimate load at mid-span section are obtained when these parameters change. Thus the mechanical properties of box girder is determined.(4) By using the established finite element analysis model, effect of prestressed concrete box girder shear lag is discussed by the factors such as load action positions and disposition of prestressing bundles. The variation of shear lag effect is obtained in different situations of load vertical and horizontal position and prestressing tendon layout in the condition of considering the material nonlinearity of concrete, These conclusions have a certain significance on the design of prestressed concrete box girder.