Study On Connection Performance Of Inner And Leaf Walls Of Precast Concrete Sandwich Insulation Wall

The prefabricated concrete sandwich insulation wall is a kind of exterior wall enclosure system,which integrates bearing,heat preservation,enclosure and decoration.It meets the requirements of green energy-saving building that has great development potential and wide application range.The connectors in the prefabricated concrete sandwich insulation wall are connected with the cooperative work and reliable stress between the inner and outer leaves of the wall body.The truss connector has the advantages of high strength,simple manufacture,convenient construction and so on among all connectors,At present,there are many deficiencies about truss connector researching in china.To study the mechanical performance of truss connector has great significance for the application and development of the prefabricated concrete sandwich insulation wall.In this paper,the tensile test,shear test and tensile-shear tests are carried out for the sandwich wall with stainless steel truss connectors,the mainly purpose is to study the mechanical properties and influencing factors of the connection under different loads.Two drawing specimens,two shear specimens and three tensile-shear specimens were made in consideration of the insulation layer thickness.The destructive process,the failure mode,the mechanical properties and the distribution and development of wallboard cracks will be observed by the test.In order to study the material property of the stainless steel truss members,the standard tensile test was carried out and measured the mechanical performance parameters of material.The numerical simulation of the test model is done by the ABAQUS finite element software,From the simulation results and the test data comparative analysis results,it indicate that they are in good agreement,meanwhile it also shows the numerical simulation method is feasible.Based on this,take the web member diameter of the truss connector,the joint spacing and the insulation layer thickness as variables to study these factors influence on the mechanical properties of the sandwich insulation wall panel by ABAQUS finite element simulation.From the test can be concluded that the failure form of the drawing test are the concrete falling off at the truss connector intersection node,the welding spot separation,and the ultimate bearing capacity and deformation of the truss connector increase with the increase of the insulation layer thickness;The failure mode of the sandwich wall shear test are the compression buckling and the tensile fracture of the truss connector web member,and the wall specimens are inclined and damaged.In addition,The ultimate bearing capacity and deformation are no significant difference between 200 mm and 250 mm insulation layer thickness of the wall;In the tensile-shear test,under different tensile force,the shear bearing capacity of the same insulation layer thickness wall decreases with the increase of the tensileforce,while in the fixed tensile force of 4.655 k N,the ultimate bearing capacity and deformation of the sandwich wall are increases with the increase of the insulation layer thickness from 200 mm to 250 mm.Through the numerical simulation with the web member diameter,joints spacing of truss connectors and insulation layer thickness as variable parameters,it can be seen that the yield and ultimate bearing capacity of precast concrete sandwich wall increases with the increase of web member diameter and the decrease of joint spacing.With the decrease of insulation layer thickness the yield bearing capacity of the wall increases,but the ultimate bearing capacity has little impact.Through a large number of calculation and analysis,this paper gives the bearing capacity of precast concrete sandwich insulation wallboard under different insulation layer thickness,which can provide reference for its engineering design and application.