Experimental Study On Hysteretic Behavior Of Circular Concrete Filled CFRP-Steel Tubes Under Compression And Torsion

Concrete-filled steel tube refers to a composite structure formed by pouring concrete into thin-walled steel tube.The two materials can exert their respective advantages and jointly bear external loads.Concrete-filled steel tube has good mechanical properties and is convenient for construction,so it is widely used in factory buildings and high-rise buildings.However,when concrete-filled steel tubes are used in environments affected by underground ice and salt or in direct contact with more corrosive water or soil,the corrosion resistance of the structure is significantly reduced.Therefore,some scholars proposed to wrap CFRP outside the concrete-filled steel tube to enhance the corrosion resistance of the concrete-filled steel tube or repair the corroded steel tube.While ensuring the stability of the structure,it can also improve the bearing capacity of the structure to a certain extent.At present,many scholars at home and abroad have carried out the research of CFRP-concrete-filled steel tube composite structure,but there are few researches on its hysteretic performance.This article studies the compression-shear hysteresis performance of circular CFRP-concrete-filled steel tubes.Based on the experiment,the V-(35)hysteresis curve and?-? curve of each specimen are measured,and the V-(35)hysteresis of each group of specimens is measured.Compare the curves and analyze the test curves.Establish a finite element model to verify the test results,compare the simulation results of each test piece with the test results,analyze the parameters under the premise of the correct model,and discuss the number of CFRP layers,axial compression ratio,concrete strength,steel content and The influence of steel yield strength and other related parameters on the V-(35)skeleton curve of circular CFRP-concrete-filled steel tube compression-shear hysteretic performance members.The research results show that increasing the number of CFRP layers can increase the load-bearing capacity of the component,and has no obvious effect on the overall shape of the V-(35)skeleton curve and the stiffness of the elastic section;increasing the axial compression ratio within a certain range can increase the load-bearing capacity of the component.Axial compression ratio,steel content,steel yield strength,concrete strength and the number of CFRP layers are the main factors that affect the V-(35)hysteresis curve.The research lays the foundation for the subsequent study on the mechanical properties of CFRP-concrete-filled steel tube shearing and related fields,and also provides a certain reference for scholars who study the shear properties of other members or materials.