Theoretical And Experimental Research On The Stressed Skin Diaphragm Of Light-gauge Steel Structures

Currently in the designing of light steel structures, profile sheets are still used as sheathing of the building. However, if proper connections are made between the profiled steel sheets and members, the sheets can resist shear force in their own plane and can be work together with the structures, which not only increase the whole rigidity of structure, but also as an important part of main body. This kind of behavior of profile sheets is named the stressed skin diaphragm. Considering its influence on the performance of the structure as a whole reflect the working of structure really and has considerable economic advantage as well. As such it is significant and practical to develop systemic investigation on the stressed skin diaphragm in the light-gauge steel structures.At first part, joint test program was conducted for the fastener made of self-tapping screw in this paper. Shear behavior of fasteners that connect various thickness sheets was discussed;at the same time, test results can be use to characterize the properties analyzing basic shear panel by finite element.In this paper whole test programs on the shear behavior of basic panel using profiled sheets connected by the self-tapping screws are carried out in this paper, which are constructed according to the detailing in practical engineering. The effects on the shear behavior of the basic panel such as sheeting section, arrangement of fasteners and puriines are studied by analyzing failure modes and shear capacities of the panel.Based on test, numerical modeling method is adopted to simulate the shear behavior of the basic panel. Test results are validated by the powerful finite element method, which themselves verify the reliability of the numerical simulations. Working behaviors of the panel under shear loads in-plane and various factors that affect its shear capacity, failure modes and mechanism are studied. Effects on the shear capacities of the panels considering various connective boundaries are also discussed in this paper.According to reasonable assumptions, this paper derives the simplified design formulas calculating strength and stiffness of shear pane, which is based on the results of test and finite element analysis. The simplified formulas are applied to the shear diaphragm using profiled sheets connected by the self-tapping screws. The test data are compared with the results acquired from the formulas and the finite element analysis. The simplified formulas can be used as a theoretical basis for specification for design of cold-formed steel diaphragm being compiled in our country.Interaction of stressed skin diaphragm and structure as a whole is studied in the last section of the paper. Based on the light-weight building with gable frames, effect of diaphragm that contributes the stiffness of main structure is also discussed. In order to quantify this effect, parameters which influence on performance of the structure as a whole are investigated, such as shear stiffeness, length and gradient of roof sheeting and shear stiffeness of gable;Recommendations for design of light gauge steel diaphragm in the practical engineering are proposed.