Flexural behavior of light steel purlins reinforced by prestressed CFRP laminates

摘要

A reinforcing technology using prestressed carbon fiber-reinforced polymer (CFRP) laminates was proposed for reinforcing steel purlins under bending. The reinforcing system can prestress CFRPs without using a hydraulic jack, which enables convenient construction and high reinforcing efficiency. The flexural behavior of the reinforced steel purlins was studied experimentally and theoretically. First, the flexural failure caused by the local buckling or yielding of the upper flange was successfully delayed by the prestressed CFRPs; the flexural capacity and stiffness were improved by 14% to 18% and 28% to 31% in tests, respectively. Then, a calculation method for determining the flexural capacity and corresponding deflection was proposed, which gave accurate results compared with the test. This study provides useful references for reinforcing cold-formed thin-walled steel beams with prestressed CFRPs.