Study On The Bearing Capability Of Light Gauge Steel Floor

The steel and lightgauge steel structures are developing rapidity and have great potency in our country by reason of rapid development of economy. The lightgauge steel structure is especially fitting into construct general industry factory building,ordinary residential houses and commercial building. The lightgauge steel floors composed of ordinary gridirons are is not only acting as storey of the structure, but also designed for working platform and sandwich.The lightgauge steel floor are designed based on ordinary steel structure design code in many designing institute due to the reasons that there is no intact design code of the lightgauge steel and the special investigative reports on the lightgauge steel structure are short too. This design method is conventional. So it is necessary to study the bearing capacity of the whole structure.For a light gauge steel floor structure with 3 spans main beam and 10 spans junior beam, Firstly, the testing deflection formulas of the middle section of main and junior beams were obtained by structural test method. Secondly, in case of leaving aside the coupling action between main and junior beams and the upper sheet steel plate' impact on the girder, the theoretical deflection formulas for the middle section of main and junior beams were obtained by theoretical analysis method. Lastly, making use of standard FEM programs, the theoretical and testing formulas were verified. The causes of differences by two researching methods and the girders' bending deflection capability influenced by the coupling action and the upper sheet steel plate' impacts were revealed. Analysis results showed that both of the girders' flexural,torsional stiffness and the equivalent width of the sheet steel participating in the deflection of the beams affected girders' deflection strongly. In the adopting of the finite element methods, the Fortran space rigid-jointed framework calculation program and the Matlab girders' bending moment dawning program were programmed besides applying the specialty finite element software-Ansys. As to the matter of data automatic transmission between calculation program and dawning program, it was solved by compiling a batch file. For the problem of joint of the girders, the stiffness matrix considering two terminals semi-rigid of the space trussing element was deduced by the medium of borrowing ideas from the non-shear distribution method simplified calculated on the semi-rigid steel framework. Then, the element stiffness matrix subfunction of Fortran source program was modified to conditional semi-rigid matrices subfunction. In turn raises, semi-rigid connection in girder was calculated by this modified Fortran program.At last, base on the comparison of the dates between test and theoretical analysis, some suggestions were advanced to economize steel products and reduce cost in the design of new analogy structure and the load-supporting capability evaluation in active service structure.