NUMERICAL STUDY ON THE EFFECT OF OPENINGS IN STEEL IPE BEAMS STRENGTHENED BY CFRP PLATS

Abstract

This paper presents the numerical study of the nonlinear finite element behaviour of steel beams with openings strengthened by CFRP plates. A three dimensional nonlinear finite element model is developed using a most famous software package (ANSYS V.14.5). The steel beam and CFRP plates were simulated by four-node shell elements (SHELL 181) and one dimensional nonlinear spring (COMBIN 39) as interface element between steel beam and CFRP plates. Parametric studies were adopted to investigate the effect of shape, locations of the web openings and number of layers of CFRP plates which were used in strengthening the steel beam. The obtained results showed that the ultimate load decreases with the increase in the opening area. Circular web openings at the shear zone of the steel beams were caused smaller decreasing in the ultimate load capacity because of a very less stress concentration at the web openings, while the beams with rectangular opening results the lesser load carrying capacity, .i.e. 38% less than their corresponding beams with circular or square opening. Applying CFRP plates around the web opening of steel IPE-beams was a successful method for increasing the load carying capacity and decreasing the deformations.Moreover, increasing the number of CFRP layers leads to increase the stiffness and shear resistance of the steel beam, hence, increasing the ultimate load capacity by ( 15-36 %).