Analysis Of Mechanic Behavior Of Steel And Concrete Composite Beams

The steel and concrete composite beams are flexural members which are made up of the steel beams and the concrete slabs working together by shear connectors. The concrete slabs are the principal pressure part and the steel beams are the primary tension part under load. So the steel and concrete composite beams not only have the good mechanical behaviors and the service performance, but also have the good economic benefits, because of the full use of two material respective mechanics characteristics. In this paper, theoretical analysis and computed research on this kind of structural mechanical behaviors including the nonlinear bearing capacity and creep effect have been finished. Main contents and outcomes are listed as follows:This paper describes design method and calculation theory of composite beams, and derives theoretical calculation formulas of temperature effect, shrinkage and creep;The software ANSYS is adopted to establish the elastic- plastic finite element analysis model for steel and concrete composite beams. In this model, the spring element is used for to simulae shear connectors between steel beams and concrete slabs. With the use of ANSYS, the nonlinear analysis of steel and concrete composite Beams have been finished, the relationship between bearing capacity, distribution law of interface slip and material strength of composite beams and interval of studs. In this paper, theoretical analysis and Shear Strength design method research of steel and concrete composite beams have been consummated;With the engineering background of Nanzhou bridge, creep calculation analysis of the composite beam is made, and the results by MDIAS shows as follows: The effect of creep on steel and concrete composite beam manifested as that, it makes stress-redistribution of cross section, and steel beam, compressive stress of which increases over time, wound undertake more stress, meanwhile the concrete, stress of which decreases, is unloaded gradually. Prefabricated bridge deck panels are joined by cast-in-place after steel beam being spanned, it makes that steel beam undertake internal force in prophase, and stress of bridge deck decreases markedly when the bridge completes, and stress-redistribution effect from creep wound be reduced efficiently.