Study On Design Method Of The Steel Encased Oncrete Composite Beams

The steel encased concrete composite beams, a new type of composite beams withreasonable and efficient form, are developed from the traditional steel-concretecomposite beams. The composite beam combines the U–shaped groove welded bycold-formed sheets and a thick steel plate with the concrete inside. Thus, concrete andsteel served as the rib of the T-shape composite beam to withstand the external load. Theresearch results reveal that steel encased concrete composite beams have the advantagesof improvements in the flexural capacity, the fire-resist capacity and the comprehensiveeconomic index of the beams, and the convenience of construction process, comparedwith traditional composite beams.The computer simulation and theoretical analysis have been carried out in thisarticle to study the new type of composite beam. The details are as follows.(1)the research status of the new steel-concrete composite beams is introducedand the issues for the new composite beams should to do next is pointed out.(2)The calculation procedure about the full shear connection compositespecimens’ bending strength of cross section is performed and compared with thecomputer simulation method. And the validity of the finite element models is verified.(3)Numerical simulation is conducted by nonlinear finite element method. Andthe distribution of concrete cracks, load-displacement curves and slip distributioncurve are acquired. In addition, four numerical models of this type of beam withdifferent spacing of the stud have also been tested. Acorrding to the tests, thedeformation characteristics and slip distribution rule is presented.(4) The nonlinear finite element analysis of the varying parameter,includingcross-sectional form and section size, is accomplished to deal with the problems incross-section design. In the analysis, the load bearing capability, bending capabilityand slip distribution are tested, and the economical section of the steel encasedconcrete composite beams is ascertained. (5)Contrastion about the mechanical performance and economic performance iscarried out between the traditional steel-concrete composite beams and the steelencased concrete composite beams, and the advantages of the new composite beamsstyle are summed up.