CFRP Strengthening of Steel Beams with Web Openings

Integration of services via web-openings in steel floor beams is often unavoidable in modern frame buildings. Such web-openings can significantly reduce the shear and bending strength capacity of the beams. Traditionally, the welding of additional steel plates to the opening areas is adopted as a means of strengthening and stiffening. This not only presents practical difficulties but can induce residual stresses which weaken fatigue performance of the section. This study explores the use of externally bonded carbon fibre reinforced polymer composites (CFRP) as an alternative means of strengthening. Using a non-linear finite element approach, the effect of strengthening arrangement is investigated with a view to finding the most structurally efficient layout. For the series studied significant enhancements of strength comparable to those achieved by welded plates, have been predicted.