Compressive And Hysteretic Behaviour Of Double Skin Steel Plate-concrete Composite Walls With Steel-bar Truss

For small high buildings,the thickness of traditional double skin steel plate-concrete composite shear wall is still too large.Thus,the double skin steel plate-concrete composite wall with steel-bar truss is proposed as the new lateral force resisting member.Advantages for the proposed wall are: the out-of-plane stiffness is high,mechanical processing is realized,production efficiency is enhanced,the steel ratio is lower,the steel plate is galvanized for anti-corrosion and fire retardant coating could not be added.Double skin steel plate-concrete composite shear walls with steel-bar truss are studied and analyzed by the axial compressive test and finite element analysis.The buckling equations of steel plate with the consideration of the initial geometric imperfection,and the calculated method of compressive maximum strength for composite walls are proposed.Based on the compressive behavior,double skin steel plate-concrete composite walls with steel-bar truss are studied and analyzed by the hysteretic test and finite element analysis,and the calculated method of resisting lateral force is poposed.Critical researches are drawn,as given below:(1)Axial compressive test about double skin steel plate-concrete composite walls with steel-bar truss were conducted and there were 30 specimens.Test parameters included welding spot spacing-to-thickness ratio,spacing aspect ratio of welding spots,connector type,steel plate slits and compared specimens of reinforced concrete shear wall.The compressive failure phenomena of double skin steel plate concrete composite wall were obtained.Influences of test parameters on the buckling stress of steel plate,stiffness of load-displacement curves,maximum strength and ductility were studied.The initial geometric imperfection should be considered in calculation of steel plate buckling stress.(2)The finite element model(FEM)of double skin steel plate-concrete composite walls was established by ABAQUS in consideration of initial geometric imperfection of steel plate.The buckling stress,load–displacement curve and failure mode obtained by FEM corresponded well with these of the test.The parametric analysis was conducted to study the influence of initial geometric imperfection,welding spot spacing-to-thickness ratio and spacing aspect ratio.The equations for steel plate buckling stress and compressive maximum strength for double skin steel plate-concrete composite wall with steel-bar truss in consideration of the initial geometric imperfection and welding spot spacing-to-thickness ratio were proposed.(3)6 experimental specimens of double skin steel plate-concrete composite shear walls with steel-bar truss were subjected to the intended combined loading in quasi-static test.Test parameters included axial compression ratio,welding spot spacing-to-thickness ratio,steel plate slits and compared specimens of reinforced concrete shear wall.The failure phenomena and modes of double skin steel plate-concrete composite wall with steel-bar truss in hysteretic test were obtained.The hysteretic curves,skeleton curves,initial stiffness,maximum strength,ductility,stiffness degradation,strength degradation,energy dissipation,shear deformation and local deformation were studied to analyze the hysteretic behavior of double skin steel plate-concrete composite shear walls with steel-bar truss.(4)The finite element model(FEM)of double skin steel plate-concrete composite walls with steel-bar truss was established by SKTO based on Opensees.The hysteretic curves,skeleton curves obtained by FEM corresponds well with these of the test.The parametric analysis was conducted to study the influence of shear span ratio,axial compressive ratio,concrete compressive strength and steel yield strength on hysteretic curves,skeleton curves.Equations about normal section compressive capacity and oblique section shear capacity of double skin steel plate-concrete composite walls with steel-bar truss were proposed.