Study On The Forced Mechanism And Shear Strength Of Steel Tube Confined Concrete Composite Shear Wall

Engineering fiber reinforced Cementitious Composite(ECC)is a new kind of construction material,which has a range of desirable properties,such as high ductility,high toughness and high durability etc.Steel-ECC structure composed of steel and ECC can take advantage of the superior performance of steel reinforced concrete structure,and can give full play to the advantages of ECC,which has a good application prospect.As a new structure combined of two different materials,the bond slip behavior between steel and ECC interface have a big influence on the mechanical properties.The reach on the interface bond properties which reflecting its working mechanism has important academic significance and engineering application value on the further research of Steel-ECC structures.Based on fiber dosage,transverse reinforcement ratio,concrete cover thickness and anchorage length as changing parameters,15 specimens were designed to proceed the static loading test,and the parameters needed to establish theoretical analysis model were obtained.Based on the experiment study on steel stub filled composite shear walls with low aspect ratio(STLW shear wall),the ABAQUS software was used to analysis the mechanical performance of STLW shear wall.Using SPRING2 spring element simulating the bond slip behavior between steel and concrete,the reasonable three-dimensional finite element analysis model of STLW shear wall was established.The finite element simulation compared with the experiment,and the results showed that the load-displacement curve of calculated using the finite element model were in good agreement with the skeleton curve of experiment.The established finite element model can simulate the bearing capacity of STLW shear walls accurately.The finite element model experienced the whole wall and seam wall phase,which had good reaction on the damage characteristics of STLW shear walls.Based on the softened strut-and-tie model,a new analytical model called the softened strut-and-slip model was proposed and used to analysis the mechanical behavior of STRC shear walls.It is found that the model can reproduce the test results with satisfactory agreement.The softened strut-and-slip model can provide beneficial insights into the mechanical mechanism of STRC shear walls.