Proposal of improvement of debonding bending moment for pre-stressed CFRP bonded steel member

Abstract

Recently, some research reports on the application of pre-stressed CFRP plate on steel members have been published. However, the shear and peeling stresses in adhesive at the end of CFRP plates are induced by releasing the pre-tension as well as bending moment. Therefore, in the strengthening of steel members with the pre-stressed CFRP plate, the CFRP plate tends to have debonding in the lower bending moment. In this study, to reduce the shear and peeling stresses in adhesive by releasing the pre-tension of CFRP plates, installation of non pre-stressed regions in CFRP plate was proposed. By installing the non pre-stressed regions in CFRP plate, dividing the locations of higher stresses in adhesive by releasing the pre-tension and bending moment were revealed. Additionally, the design equation of length of non pre-stressed regions was also presented.