Research On Stability Capacity Of Square Hollow Section Columns Strengthened With CFRP Under Axial Load

Strengthening the steel structures with Carbon Fiber Reinforced Polymers (CFRP) is one kind of reinforcement technologies which has unique advantages. It has become a hot research issue at home and abroad recently. At present, there are several researches on the stability capacity of axial-loading steel members strengthened with CFRP sheets, especially on short steel columns and reduced scale columns. But the insufficient research of long steel columns strengthened with CFRP is a limitation in forming the complete reinforcement theory. This paper corrected the existing calculation formulas by experimental study and finite element software analysis, which provide theoretical basis for engineering application.After comparing and summarizing the massive research achievements at home and abroad, this paper proposed the stability capacity calculation formula using the equivalent section method proposed by British Construction Industry Research and Information Association (CIRIA) in Strengthening Metallic Structures Using Externally Bonded Fibre-reinforced Polymers. Then it conducted axial loading test of full scale square hollow section structural members strengthened with CFRP sheets. According to the test results, this paper corrected the stability capacity calculation formula after considering the effect of CFRP fiber orientation. Finally, this paper carried out the numerical simulation analysis of axial loading test using the ANSYS finite element analysis software.This subject is supported by national standard Design Code for Strengthening Steel Structure and the research findings of this paper will provide theoretical and experimental bases for writing this standard.