Abstract：Research purposes：The structure of steel arch has considerable advantages which attracts many designer and was applied to the construction of modern public architecture with long arch. The facade of the  Chongqing West Railway Station is a long arch structure with two quadrilaterals. In order to analyze the stress and partial displacement distribution of the station facade under natural gravity,we construct 3D structural and geometric models of the steel arch by the finite element method in ANSYS. We build up a three-dimensional geometric model of a full arch structure and mesh the structure model of the facade arch and then we set the initial conditions and boundary conditions.
Research conclusions：The compound arch is gradually deforming and the deformation process is spreading from center to all around the structure.Through the computing process by ANSYS, it is clear that in the horizontal direction,the displacement reaches the maximum level on both sides of the lower layer, and in the vertical direction the center of the upper layer has its displacement at a peak level.In addition,by the tangential force analysis in the horizontal direction,it is showed that the arch structure owns the favorable stiffness property that can effectively transmit the horizontal force whereas by the vertical stress analysis. It further confirm that the arch structure can efficiently absorb part of the shear force exerted on it in the vertical direction,which is distinct that the outer force loads concentrate on the arch surface andmuch attention should be paid to the reinforcement and crack of this the part. The research results can be aplied to the practice and theory research of steel arch structure.
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