Study On The Lateral Stiffness Of Cold-formed Steel Stud Composed Wall

Based on consulting a lot of documents, detailed results on the lateral behavior of cold-formed steel stud walls in low-rise residential structures by tests and nonlinear finite element analysis,a simplified formula for calculating the lateral displacement under lateral load of this composed walls is presented in this paper.The lateral behavior of cold-formed steel stud walls under monotonic and cyclic loads is tested of full-scale specimens in this paper. The test specimens included walls with single-gypsum and walls with single oriented strand board sheathing. The trial devices, test method and full test course as well as the analysis of test data are introduced in detail in this paper. Test results show that: different loading methods on the wall influence wall's shear resistance greater; with different panel materials, the shear strength, initial stiffness , yield load, maximum load and the stiffness at maximum load of single-gypsum sheathing wall is greater than the OSB sheathing wall, but its deformation ability is ever poorer; with opening, the greater the area of the opening, the lower the shear resistance and the lateral rigidity, but the ductility is just on the opposite.Nonlinear finite element analysis involving geometric large deformation and materials nonlinear is used to simulate test walls under monotonic load in this paper. Members are modeled as shell elements. The screws connecting of the sheathings to the frame are modeled as beam elements. The equation resolution method is selected by ANSYS program automatically. The finite element analysis results are in good agreement with that of tests, which proves that the finite element analysis is correct and feasible. On this basis, a series of internal factors such as the steel strength, the screws spacing, the sheathing properties and other tectonic factors such as the wall height, the size of the wall opening, using X-shear-support or not are analyzed, the results showed that: the strength of steel members influences the shear resistance of walls lightly. Decrease surrounding screw space can more effective improve wall shear properties, but the effect is not so obvious; Comparatively speaking, the use of the larger elastic modulus sheathing, reducing the height of the wall, using X-shear-support can large improve the anti-raising properties of the wall.Through the above analysis, this paper proposes a simplified calculation formula for horizontal displacement under horizontal load of this composed wall ,which can well calculated the load displacement of the former design values, but after that ,its result is gradually from with the experimental results, so it can only be used the calculation of the displacement under normal work of the wall, and it can not be used when the wall load is greater than wall design load, that is,the formula can not be used to calcute the plastic deformation of the wall.