TheExperimental investigation of the damaged B.F.I. Beamrepaired by CFRP under the Static and fatigue loads

Abstract

The objective of this paper is to investigate the Structural behavior of the damaged steel B.F.I. Beam (No. 10) under fatigue load (repeated load by 40% the value that produces a static failure) and make a comparison with the static loads for the same specimen. Which repaired and reinforced by Carbon fiber polymers strips (CFRP) (3*10cm * 100cm), fixed at the center of the tension flange and 8 strips (8*8mm*10mm) were distributed and fixed to the two faces of the web. The damage is created by notching (4mm) in the center of the tension flange for the six beams and two beams were damaged by the failure test of the two control beams. We have ten B.F.I. Beams, five beams were tested under static load and the other five beams under fatigue load with different ways of reinforcing by the layers of CFRP. We make an experimental comparison between the behavior for the ten beams under static and fatigue loads. We noticed that CFRP patching resulted in improvement in fatigue life of the damaged beams of up to 6.4 times over that of unrepaired beams, and to 1.8 % for static load cases, CFRP strips moderate fatigue crack propagation. The reinforcing to the web work as a stiffeners improve the shear failure and the deflection.