Web post-buckling strength of thin-webbed cellular beams using carbon PFRP profiles

Currently, cellular steel beams are widely used by structural engineers and major companies due to their useful structural applications and serviceable performance. However, these types of steel beams are susceptible to different states of instability and failure mechanisms such as web post buckling. The aim of this paper is to investigate the effectiveness of using externally bonded pultruded carbon fiber (CFRP) profiles for the strengthening of web post-buckling in thin webbed cellular beams as an alternative to the typical welding technique of reinforcement. A proposed numerical model created with the finite element software ABAQUS capable of capturing the de-bonding and fracture along the adhesive layer between steel and CFRP has been validated using published experimental results. The suggested numerical model is then used to simulate the parametric analysis of using pultruded CFRP T and U sections to strengthen six cellular beams of various sizes. It was found that this novel technique was able to prevent the web post-buckling failure mode or delay it to a grater load with a considerable strength enhancement comparable to control beams.