Effective Rigidity Of Stiffeners In Steel Shear Wall And Slab Effective Breadth In Steel-Concrete Composite Beam

Stiffened plates had been widely used in bridges,aircraft and ship structures.Now it was applied to high-rise bulidings,as stiffened steel shear wall.Compared to unstiffened steel shear wall,stiffened steel shear wall can absorb a certain amount of vertical load and have a better ability of energy dissipation after buckling.It was conform to the habit of seismic design in our country.The bending stiffness and torsional rigidity of stiffeners have a big effect on the shear-buckling of steel shear walls.One-side stiffened plate was a more efficient stiffened structure which had more extensively applicable scope.Senior civil construction steel structure design codes suggest using one-side stiffener in steel shear wall.The bending neutral axis of stiffener was between the centroid of stiffener and the middle of the plate.It's position depends on the effective breadth of plate.This paper was focused on studying the effective bending stiffness and torsional rigidity of one-side stiffener in reinforced steel shear wall.The stiffener and the plate were isolated and acted by their interactive forces along the connecting line.The plate was analyzed as loaded by in-plane and out-plane loads.The stiffener was analyzed such as simply supported beam.Finally they were combined to satisfy the continuity conditions in the longitudinal strains and the deflections on the connecting line.Analytic equation of critical load of the one-side stiffened plate under uniaxial compress was obtained.Analytic expression of effective bending stiffness of the one-side stiffener under lateral pressure was also obtained for the sinusoidal wave form,the effective breadth of the plate taking part in the function of the stiffener was found.The effective breadth was indispensable while calculating the effect of shear deformation.The influence of shear deformation can't be ignored when the depth-span ratio of the stiffener was large.When the plate was arranged two one-side stiffeners,the effective breadth of one-side stiffener was different from the effective breadth of plate with single one-side stiffener.This paper analyzed the buckling of plate arranged two one-side stiffeners.The analytic expression of effective breadth was obtained.Reavealed the relationship between the amount?arrangement spacing?buckling mode and the effective breadth of one-side stiffener.Steel-concrete composite structure was another application of stiffened plaste in civil construction.At present,domestic researches on the slab effective breadth of composite beam were not considering the influence of the steel quantity and arrange distance.This paper researched the slab effective breadth of steel-concrete composite floor slab arranged with steel beams.Presented the analytic expression of the slab effective breadth of the composite slab arranged 1?2 steel beams,when the load was s sine or uniformly distribution.The slab effective breadth would decrease with the increase of the amount of steel beams.Studied the cracking of the concrete slap.The concrete cracking model was put forward.Through the analysis of plane stress,the factor of slab effective breadth in composite beam was abtained.