Proposal of a methodology based on finite element analyses for the design of bonded cfrp reinforcement of steel cracked elements

CICE 2018, Conférence internationale sur les composites à matrice polymère renforcée de fibres en génie civil , PARIS, FRANCE, 17-/07/2018 - 19/07/2018; Recent studies have shown the efficiency of the application of carbon fiber reinforced polymer (CFRP) materials to reinforce cracked steel elements even in the case of old steel materials (mild steel and puddled iron). Bonding CFRP materials on cracked steel plates leads indeed to a significant reduction of the stress intensity factor (SIF) at the crack tip and thus to a significant increase of the fatigue life. This is even more pronounced when using ultra-high modulus or pre-stressed reinforcement. This could allow extending damaged steel structures service life or securing a structure waiting for a more complete refurbishment. Yet, there is currently a clear lack of design tools for the design office to be able to apply such reinforcement or repair technique.The presented work concerns the appraisal of a methodology based on the use of finite element modelling to determine the stress intensity factor modification ratio. After the presentation of the proposed methodology, it will be compared with experimental investigations led by the authors on different steel substrates and with different reinforcement processes. This comparison will allow to identify the precision of the method, and to be able to highlight its strengths and weaknesses. Finally, parametric analyses will be done to assess the impact of different design characteristics on the increase of fatigue life