Optimal Design Of Steel- Concrete Composite Beam

This paper, combined with the actual project case, made a more detailed analysis to steel-concrete composite beam bridges.Firstly, I took a comparative analysis of the elasticity theory and the elastic-plastic theory of the composite beam. Then I calculated the entire stress distribution, deflection and elastic ultimateflexural capacity through elastic theory, derived the reduction factor of bearing capacity due to sliding, and investigated the calculation method of composite bridges’ ultimate flexural capacity.Secondly, I structured the member model based on the elasticity theory and the finite element model considering material nonlinearity, suitable units and material constitutional relationships. According to the contrast of two stress calculating results and comparing the former calculated elastic ultimate flexural capacity with the latter calculated plastic ultimate flexural capacity, the suitable calculated method of bearing capacity was determined.Again, I carefully analysed and researched the related parameters of simply supported composite beams. Because of changing steel strength, concrete strength grade and section size, I researched the effect on composite beams’ stress state, ultimate flexural capacity, integral rigidity, rigidity distribution between bridge deck and steel beam, consumption of concrete and steel and so on in normal use because of changing steel strength, concrete strength grade and section size.Lastly, according to girders’ stress index and ultimate flexural capacity, steel members’ local stability and corrosion resistance in normal use, I suggest the reasonable thickness and size range of steels’ each component and concrete slab.