Research On Seismic Performance Test And Calculation Method Of Fully Assembled Composite Wall

The green assembled composite structure system is a new system of assembled building structure with energy dissipation,shock absorption and ecological environmental protection.Filling in ecological materials can effectively alleviate the consumption of raw materials and the recycling of some construction wastes.At the same time,due to its special materials and structure structure,its bearing system has three clear seismic defense lines.In order to meet the development requirements of prefabricated composite structure system and solve the problems of complex joint connection,poor reliability and poor overall performance of the structure,the new wall boundary connection technology has become the key problem to be solved in the development process of prefabricated composite structure system.In this paper,the green assembled composite wall structure and the new wall boundary connection technology are combined organically.The green assembled composite wall structure is proposed.A variety of horizontal joint and vertical joint dry connection methods are proposed.The research adopts the combination of experimental research,numerical simulation and theoretical analysis By means of this method,the seismic and mechanical properties,the deformation law of horizontal and vertical joints,the slip and strain distribution of connectors of this kind of wall under low cyclic reciprocating load and monotonic load are systematically studied,and the corresponding design and calculation theory is established.The main work of this paper is as follows:(1)Four fabricated composite walls with different dry-type joints are designed in the experiment,which are respectively connected by sleeve grouting,welding,box and bolt.The low cycle reciprocating loading test is carried out to compare the failure mode,hysteretic characteristics,bearing capacity,deformation capacity,stiffness degradation and energy consumption capacity of the four different types of walls.Five horizontal joint bolt connected wall specimens are designed for monotonic loading test.The failure mode,horizontal load displacement curve,bearing capacity,deformation capacity,stiffness degradation,strain distribution of connecting steel plate,relative slip between connecting parts and wall panel are compared and analyzed.The composite wall connected by horizontal joint bolt is established The parameters of the model are expanded and analyzed.The influences of the height width ratio,axial compression ratio,thickness of connecting steel plate,specification of high-strength bolt,concrete strength,block strength,diameter of longitudinal reinforcement of rib column,diameter of longitudinal reinforcement of rib beam,initial stiffness and other performance indexes are studied.(2)Based on the two-way fiber single-layer composite model,the calculation model of the composite wall connected by the horizontal joint bolt in the elastic stage is established.Considering the influence factors of the height width ratio,the axial compression ratio and the thickness of the connecting steel plate,the calculation formula of the lateral stiffness of the composite wall connected by the horizontal joint bolt is proposed.On the basis of experimental research and numerical simulation,the oblique section of the composite wall connected by the horizontal joint bolt is established The simplified calculation model of face shear bearing capacity is put forward.T he calculation model of horizontal joint of composite wall connected by horizontal joint bolt under shear is established,and the calculation formula of wall shear bearing capacity of horizontal joint is put forward.(3)Three kinds of dry connection methods for vertical joints of prefabricated composite walls are proposed,which are box connection,bolt connection and U-shaped steel plate connection.Five dry connected double prefabricated composite walls with vertical joints are designed to carry out low cycle reciprocating load test,and the failure mode,failure process,hysteretic characteristics of different vertical joints are compared Displacement ductility coefficient,vertical joint deformation and other properties,as well as the influence of the thickness of vertical joint connecting steel plate on the seismic performance and joint deformation capacity of the wall.(4)Combined with the experimental research and numerical model expansion analysis results,axial compression ratio,thickness of connecting steel plate and other factors on the bearing capacity,initial stiffness and other performance indexes of the test piece is studied;based on the simplified calculation model of lateral stiffness of single composite wall,the influence of vertical joint on lateral stiffness is introduced,and the practical calculation formula of lateral stiffness of double wall is proposed;the vertical joint is established The simplified calculation model of shear bearing capacity of double walls connected by joint bolts is proposed.the main failure mechanism and failure factors of vertical joint bolt connection are analyzed,the calculation model of shear bearing capacity of vertical joint is established.Based on the calculation of shear bearing capacity of horizontal joint of single wall,the calculation formula of shear bearing capacity of double walls is established The shear bearing capacity calculation model of the horizontal joint of the wall is proposed,and the calculation formula of the horizontal joint bearing capacity of the double wall is put forward.(5)Combined with the experimental research and numerical model expansion analysis results,based on the existing p-a-m damage model,the paper improves the displacement beyond the damage threshold,establishes the improved p-a-m damage model for the double composite walls with vertical joint dry connection,carries out the damage index simulation analysis in different stages,studies the impact of vertical joint connection on the damage performance of each test piece,and establishes the vertical joint The numerical model of two composite walls connected by U-shaped steel plates is used to study the influence trend of the thickness of U-shaped steel plates on the energy dissipation capacity of the walls through the parameter analysis of the connectors.