Study On Seismic Performance Of New Type Cold-Formed Steel-Paper Strawboard Composite Walls

The light steel structure house has lightweight,high degree of assembly,and good earthquake resistance.It is a prefabricated green building with a wide range of application prospects.At present,as the authority vigorously promotes the construction of ecological civilization,the shortcomings of insufficient greening of traditional wall panels for light steel houses have become increasingly prominent.Based on this,our research group has applied the green building materials-pape straw board to the light steel house and conducted a lot of mechanical performance research on the cold-formed thin-walled C-shaped steel-paper straw board composite wall.Meanwhile,the bearing capacity of this type of wall can meet the requirements of existing specifications.However,the fly in the ointment,the lateral stiffness is slightly lower.In order to solve these problems,this paper proposes a new type of light steel-paper straw composite wall with a built-in steel plate based on the cold-formed thin-walled C-shaped steel-paper straw composite wall.To solve such problems,this paper proposes a new type of light steel-paper straw board composite wall with built-in steel plate based on the cold-formed thin-walled C-shaped steel-paper straw board composite wall.This enriches the types of light steel composite walls and can promote the buildings’ greening and industrialization.The test and numerical simulation analysis on the seismic performance of this composite wall were conducted.The main contents and conclusions are as follows:In this paper,low-cycle reciprocating horizontal loading tests were carried out on seven wall specimens.The test variable parameters include the presence or absence of steel plate,steel plate thickness,single/double-sided steel plate,and the steel plate placed inside/outside of the straw board.By drawing the hysteresis curves and each specimen’s skeleton curves,the characteristic value of the bearing capacity and its degradation law,the lateral stiffness and its degradation law,the ductility coefficient,and the energy dissipation coefficient,and other seismic performance indexes of each specimen were obtained.The results show that the failure mode of the composite wall with the steel plate placed on the inner side of the strawboard is the bulge of the steel plate and the wrinkles of the straw board,the loosening of the self-tapping screws at the end of the specimen,and the severe buckling of the end stud until tearing failure;the failure mode of the composite wall with the steel plate placed on the outer side of the strawboard is that the buckling failure of the steel plate near the bottom of wall and the wrinkles of the straw board,the loosening of the self-tapping screws at the end of the specimen,and the buckling failure of the end stud;The steel plate improves the shear resistance of the wall such as the characteristic value of the shear capacity and the lateral stiffness;the composite wall with steel plates placed on the inner side of the straw board have higher bearing capacity,lateral stiffness,ductility and energy dissipation performance than that with steel plates placed on the outer side;the composite wall with double-sided steel plate has higher bearing capacity than single-sided steel plate,but the growth of capacity is not linear;the increase of the thickness of the steel plate can improve the bearing capacity and lateral stififness.According to the test results,the finite element model considering material nonlinerity and geometric nonlinearity was established using ANSYS.Shell element was used to simulate steel frame and sheathing.The finite element simulation result was consistent with the test in the failure mode and bearing capacity characteristic value,indicating the finite element modeling is reasonable.The finite element parameter analysis of the composite wall was carried out to study the effects of thicknesses of steel plates,different strengths of steel for steel stud,wall height-to-width ratio,and self-tapping screw spacing on the seismic performance of the wall.By rationally simplifying the composite wall,using the shear flow calculation method and introducing the correction coefficient,the formula for calculating the shear bearing capacity of composite wall is deduced.The theoretical results calculated by the formula agree well with the test results.Simultaneously,suggestions are made for the sub-factors of the bearing capacity in the ultimate state design method,which provides a reference for the engineering design of this type of wall.