Mechanical Behavior of I-shaped CFRP Profiles-high-strength Concrete-filled High-strength Circular Steel Tube Middle-Long Columns under Eccentric Loading
To avoid material waste and reduce the section size of the member,CFRP profiles and high-strength concrete-filled high-strength circular steel tube is combined to form I-shaped CFRP profiles-high-strength concrete-filled high-strength circular steel tube,and their mechanical performance under eccentric compression are studied.The working mechanism and failure mode of the composite members were studied by the combination of test and finite element method.The typical members were selected for the whole process analysis and variable parameter analysis.The results showed that the load-deflection curve of typical members can be divided into an elastic section,elastic-plastic section,plastic strengthening section,and descending section.The proportion of load borne by CFRP profiles after the elastic-plastic section gradually increases and can work together with the steel tube,forming double constraints on the concrete and improving the ultimate bearing capacity of the members.The slenderness ratio and eccentricity have an obvious influence on the ultimate bearing capacity,initial stiffness,and ductility of the members,while the steel yield strength,concrete strength,steel ratio,and CFRP configuration rate have little influence.The deformation of the specimen is stable and the ductility is good,and the deformation of the specimen conforms to the plane section assumption.