Bearing Capacity Test Research And Analysis Of Light-Gauge Steel Biaxial Bending Truss Beams

In recent years,the light gauge steel is widely used in the lower and multi-storey structures for its huge economic advantage, good seismic behavior and the advantages of energy conservation and environmental protection. Because the biaxial bending steel beams are difficult to fabricated and complex construction of joins, the floor and roof beams are usually one-way arranged on the top of two steel walls, meaning the other walls lose role to transfer the loads from the beams and beam cross section is high stiffness is relatively small.The majority beams in the light-gauge steel are solid-web beams or truss (rigid) beams.This paper presents a new kind of biaxial bending beam, composing of several one-way truss beams in two directions. The upper and lower chords of truss beam are cold-formed rectangle sections of40×20×1.2mm,with a small height and big width, forming one-way truss beam together with the web members and screws. The web members is Z standard connector, it is made of p25circular tube stamped and bended at the end.This paper introduces detailedly material, composition, fabrication and installation of biaxial bending truss beams of light-gauge and its characteristics are summarized. Then full scale3mx3m biaxial bending truss beam and one-way truss beam with same length were tested under the vertical uniform loads. The sample detail, testing sets and loading method are introduced. Measure the strain and deflection of the type areas of the beams in each load level,get the ultimate bearing capacity and failure mode, Make out the Load-Displacement curve and the Load-Strain curve and carry on the comparison.Additionally, the mechanical behavior,displacement,failure mode and loading capacity were analyzed by the finite element analysis software. There are no very good coincide between the analysis results and testing data and the reason was provided. The displacement is little large for the biaxial bending beam base on the research, showing that this kind of biaxial bending beam can be used for the light weight floor or roof.Finally, experimental and theoretical study of light-gauge steel biaxial bending truss beam are suggested in this paper. All of these provide some references for the future practical engineering design and the direction of future research.