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

The cold-formed thin-walled steel structure has the characteristics of durability,environmental protection and good recycling,which has become the key promotion and development direction of the current prefabricated buildings.The cold-formed thin-walled steel composite wall bears both vertical and horizontal loads,and the research of its lateral stiffness is a hot spot at present.Straw brick problem is a traditional problem in China’s agriculture.Under the background that the country has banned burning straw,the treatment and application of straw need more research.Combine straw brick with cold-formed thin-walled steel composite wall,give full play to straw brick’s functions of heat insulation and warmth preservation,and realize the goal of turning waste into treasure in the building.In this paper,the combined wall formed by cold-formed thin-walled steel and straw brick is tested under monotonic horizontal loading,and the lateral stiffness of the combined wall under monotonic loading is studied,which provides a reference for the future structural application.The research work of this paper mainly includes the following aspects:In this paper,the important components of the composite wall,including steel,straw brick,cement mortar and wood in the steel frame,are tested for the material properties,which paves the way for the following tests and theoretical analysis.In this paper,the detailed structure of the composite wall,the process of making,the layout of measuring points,the experimental device and the experimental scheme are introduced in detail.Based on the analysis of the experimental phenomena,it is shown that the failure type of the wall is shear failure,and the failure of the wall is due to the local collapse of the wall panel,resulting in a significant reduction in the shear capacity of the wall.The accuracy of the finite element model is verified by comparing the experimental results with the finite element model.On this basis,the finite element model expansion parameter analysis is carried out,and some factors that may affect the shear bearing capacity of composite wall,such as X-support,yield strength of steel and strength of wall mortar,are studied.The results show that the shear bearing capacity and lateral stiffness of composite wall are greatly affected by the strength of X-support and wall mortar,and the yield strength of steel has great influence on the shear bearing capacity and resistance of wall The influence of lateral stiffness is small.In this paper,the cement mortar wall is assumed to be an equivalent strut and tie method,and the lateral stiffness of composite wall is calculated.By using the superposition principle,the lateral stiffness values of composite walls are obtained by superposition of X-braced and double-layer cement mortar walls,which are equivalent to tension and compression bars respectively.Comparing the theoretical calculation values with the experimental results,it is found that the two results are quite consistent,which shows that the formula can be applied to the lateral stiffness calculation of composite walls.