Structural behaviour of composite steel girders

Abstract

Nowadays, carbon fiber reinforced polymer can be used to strengthen steel sections. Strengthening is required due to changes in design philosophy. An experimental study will be carried out on strengthened steel girders to assess their structural behavior and the merits, if any, of the addition of carbon fiber to steel. The study focuses on the shear behavior of steel girders and explores the influence of carbon fiber on the structural capacity of the girder. Carbon Fiber Reinforced Polymer (CFRP) was produced in the University of Balamand Mechanical Engineering laboratory using hand layout process and is documented in this study. The CFRP were designed to be cut and placed as strips in various locations along the web of the steel girder. Due to unforeseen circumstances and time limitations the aim of the study was diverted towards the analysis of the application of CFRP to the flange of a steel H-beam. The CFRP was placed on the flange where buckling is estimated to take place. The beam was then tested under 4-point bending where load, deflections and strains were measured. It was observed that at the location of CFRP the flange had a better structural performance when compared to the side with no CFRP. It is therefore recommended to consider strengthening beams with CFRP at locations where failure is anticipated. Further study on the application of CFRP to steel girders is necessary especially in the area of shear and combined bending and shear load configurations.