ENERGY RELEASE RATE OF MULTI STEPPED CFRP BONDED STEEL PLATE

Abstract

 In Japan, the repair and strengthening method by bonding carbon fiber reinforced plastic (CFRP) of lightweight and high strength to corrosion damaged steel member has begun to be applied. In 2018, JSCE issued “Guidelines for Repair and Strengthening of Structures using Externally Bonded FRP”, and the energy release rate was employed to the checking of debonding of CFRP. On the other hand, the multi-step CFRP bonding repair was proposed for the reduction of stress concentration in the adhesive at the end of CFRP. However, the calculation procedure of the energy release rate of the multi-step CFRP and the shorter step length of CFRP has not been proposed. In this paper, it was clarified that the energy release rate of any step condition of CFRP bonded steel plate under uni-axial loading can be calculated by applying the eigenvalue analysis and using the simple equation of shear stress in the adhesive.