Development & Application Of Preprocess Program Using 3D Solid Element Of Prestressed Concrete Box Girder

The prestressed concrete box girder is wide used in simple-supported beam, cantilever, continuous beam, continuous rigid frame bridge and cable-supported bridge. The prestressed concrete box girder appears a special stress under vertical force and three dimension prestress. The result calculating by existing programs can't reflect the exact stress distributing. The general FEM program can do the spatial analysis of box girder, but the modeling is very complex and it is difficult to consider the prestress. In order to solve these problems, I develop a pre-process program using MATLAB to generating 3D solid element model and simulating the three-dimension prestress. The calculation and post-process are done in ANSYS. At last, the analysis of a single cell box girder is done as an example and a testify.Research the method of generate 3D solid element model of prestressed concrete box girder. Realize the mesh control of box girder. The solid element model generated by using the preprocess program is regular and exact, especially convenient. The box girder types of generation by using preprocess program conclude uniform box beam, variable cross-section box beam, single cell box girder, several cells box girder, straight box girder and curves box girder.Research the geometry description of special prestressed strand, the loss of prestress and the simulation of prestress. Develop the program to simulating the three-dimension prestress.Through the example of prestressed box girder bridge, research the stress distributing of box girder under three-dimension prestress and the affect to stress distributing when transverse and vertical prestress applied.