Theoretical Research On Bearing Capacity Of Cold-Formed Steel C Section-Light Weight Aggregate Concrete Composite Beam

Cold-Formed Steel C Section-Light Weight Aggregate Concrete Composite Beam has a dual advantage of Light Weight Steel-Concrete Composite Beam and Light Weight Aggregate Concrete Structure. It has lots of outstanding merits-light weight, saving steel, high bearing capacity, good ductility and seismic performance, for example. This new Composite Beam could achieve better economic and social benefits, it is more suitable for High-Rise Buildings, Long-Span Structures and Light -Weight Steel Structures. It is an ideal structural member with good prospects for development. But at present in our country researching on Cold-Formed Steel C Section-Light Weight Aggregate Concrete Composite Beam is only in its infancy. There is-no complete theory and methods for this new Composite Beam, so it is highly desirable to make an intensive study of it.With the help of nonlinear finite element theory and existing analysis methods of Steel-Concrete Composite Beam, according to the experimental studies of Cold-Formed Steel C Section-Light Weight Aggregate Concrete Composite Beam by Professor ZHAO Gen-tian of Inner Mongolia University of Science and Technology, this paper selects one of Composite Beams to make theoretical analysis, this mainly includes two aspects:1. This paper uses ANSYS analysis software to simulate Composite Beam, takes the relative slips between concrete slab and steel beam into account, and establishes a reasonable finite element force model considering Slip Effect, then compares simulated results with experimental results, and draws some conclusions.2. Since the current Code for Design of Steel Structures (GB50017-2003) uses the reduction of stiffness to calculate the deflection of Composite Beam, however, this method is mainly for traditional Steel-Concrete Composite Beam. It is not clear that formula is applicable to Cold-Formed Steel C Section-Light Weight Aggregate Concrete Composite Beam. This paper uses mini-element analysis, and combines the interface slip and curvature relationship to deduce differential equation for the deflection of Steel-Concrete Composite Beam. Finally forms the numerical algorithm for Cold-Formed Steel C Section-Light Weight Aggregate Concrete Composite Beam.3. By changing the strength grade of light weight aggregate concrete and the thickness of the concrete flange plate, this paper mainly discusses the influencing factors on the deflection of this new type Composite Beam. The sectional flexural stiffness has played an important role on the deflection of this new type Composite Beam. By means of ANSYS modeling and deflection calculation formulas, this paper can draw a conclusion that changing the thickness of the concrete flange plate is more effective to improve the performance of Composite Beam and reduce the deflection value than changing the strength grade of light weight aggregate concrete.