Nonlinear Analysis And Optimal Design Of Prestressed Steel-Concrete Composite Beam

Based on ANSYS programs,the nonlinear finite element models of two-span prestressed steel-concrete continuous composite beam were established. The main work and some important conclusions included as follows:1.Using nonlinear finite element method,this paper calculates and analyzes the whole bearing process of prestressed composite beam,the elastic ultimate deflection and bearing capacities are evaluated and the load-deflection curve is also obtained,moreover compares calculating results with experimental results.From the analysis results,we can kown that the results of using calculating model and method coincide with the experimental results,which proves that the finite element analysis can be used instead of some test research.2. Analysis were conducted to investigate the flexural capacity and slip property under different parameter,such as concrete strength,steel strength,degree of shear connection,prestressing of the external tendons,etc. It shows that:(a)The lower concrete strength as well as degree of shear connection will result in the reduction of the flexural capacity;(b)Concrete strength has greater influence on mechanical performance of the beam than the prestressing of the external tendons and steel strength, the higher prestressing of the external tendons will result in the reduction of the deflection of prestressed composite beam through the whole bearing process, the lower steel strength as well as lower degree of shear connection will result in the reduction of the deflection increment.3. The synthesis comparison of web height,bottom flange plate thickness, web thickness, top flange plate thickness and concrete slab thickness and the section optimization design were carried on.The comparison result indicates that steel web height,concrete slab thickness and bottom flange plate thickness are strong factors, web thickness and top flange plate thickness are weak factors. The optimization result indicates that the method is efficient to optimize the section of composite beams,so it could be applied extensively in the engineering of composite beams section optimization design.