Double-layer Steel Plate Filled With Lightweight Aggregate Concrete Study On Seismic Behavior Of Composite Shear Wall

Reinforced concrete shear walls in high-rise buildings need to bear the horizontal and vertical loads caused by great earthquake action.Ordinary reinforced concrete shear walls are difficult to meet the needs of more and more ultra-high and ultra-large construction projects in today’s era due to their shortcomings such as self-importance,poor ductility and difficult construction.The double-layer steel plate concrete composite shear wall has the advantages of high steel structure strength,good ductility and high lateral rigidity of the reinforced concrete structure.It can better play the material performance in the super high-rise building structure,meet the structural safety and engineering requirements,and is convenient construction.In recent years,scholars from various countries have gradually increased the research on double-layer steel-concrete composite shear walls,and gradually applied them in practical engineering.There are no actual examples of earthquake damage.Lightweight aggregate concrete has the advantages of light weight,high strength,and environmental protection.It is gradually used in engineering.At present,there are relatively few domestic and foreign researches on seismic tests of double-layer steel plates filled with lightweight aggregate concrete composite shear walls.In order to give full play to the advantages of the double steel plate shear wall structure and promote the engineering application of lightweight aggregate concrete,it is necessary to analyze and discuss the seismic performance of the composite steel shear wall with double-layer steel plate filled with light aggregate concrete.In this paper,the ABAQUS software is used to establish the finite element analysis model of the double-layer steel plate filled lightweight aggregate concrete composite shear wall under the action of earthquake.The experimental results of the existing literature verify the rationality of the finite element modeling and analysis methods in this paper.On this basis,the influence of the thickness of the steel plate,the strength of the lightweight aggregate concrete,the axial compression ratio,the shear span ratio,the end column constraints and other parameters on the seismic performance of the composite wall are analyzed,and the double-layer steel plate filled with light bone is given Structural design recommendations and calculation formulas for shear capacity of composite concrete composite shear walls.The main conclusions of this study are as follows:1.Steel plate thicknessAccording to the research results of this paper,the thickness of the steel plate has a great influence on the seismic performance of the composite shear wall.Increasing the thickness of the steel plate can greatly improve the bearing capacity of the combined shear wall,can also improve the ductility and energy dissipation capacity of the combined shear wall,and reduce its stiffness degradation effect.In this paper,the economic index of steel plate thickness is also studied.When the thickness of the steel plate is 1/20～1/30 of the total wall thickness,the economic index of the steel plate thickness is the best.2.Lightweight aggregate concrete strengthAccording to the research results of this paper,the strength of the lightweight aggregate concrete has a certain effect on the seismic performance of the composite shear wall,but the effect is weaker.Increasing the strength of the lightweight aggregate concrete can improve the bearing capacity of the composite shear wall,but the lifting effect is not obvious.Increasing the strength of the lightweight aggregate concrete can also improve the ductility and energy dissipation capacity of the composite shear wall,and reduce its stiffness degradation effect It is recommended to use light aggregate concrete with strength grades of LC40 and LC50.3.Axial pressure ratioThe increase of the axial compression ratio can increase the bearing capacity of the combined shear wall to a certain extent,but the calculated force-deformation relationship curve will become steeper after the bearing capacity reaches the limit,that is,the bearing capacity will fall faster.At the same time,the improvement of the axial compression ratio will reduce the ductility and energy dissipation capacity of the combined shear wall,so the axial compression ratio of the combined shear wall should be controlled in the design process.With reference to "Technical Regulations for Steel Plate Shear Wall" [1] in the case of seismic class 1 level,the limit value of the axial compression ratio of the steel plate shear wall is 0.5.The calculation results in this paper show that the axial compression ratio is 0.35 and 0.40.Ensure the bearing capacity of the combined shear wall and ensure its ductility.4.Shear span ratioThe improvement of the shear-span ratio will reduce the bearing capacity of thecombined shear wall,and will increase the ductility and energy dissipation capacity of the combined shear wall,so the shear-span ratio should be moderate in the design,which can ensure the bearing capacity of the combined shear wall.,Without losing its ductility and energy dissipation capacity,according to this article,the best shear span ratio is 1.8～2.0.5.With reference to the domestic and foreign codes and research data,based on the existing double-steel concrete shear wall shear capacity formula,analyze the contribution of steel plate items,concrete items,steel bar items,etc.to the bearing capacity,and carry out the relevant formulas and coefficients.Adjust to give the formula of the shear capacity of the composite shear wall with double-layer steel plate filled with light aggregate.