Bond behaviour of FRP strengthening applied on curved masonry substrates: Numerical study

Aim of the present paper is to numerically investigate the bond behaviour of FRP strengthening systems externally applied on curved masonry specimens. In particular, considering the simple spring-model approach proposed by the authors in previous research, a new constitutive law derived from the work of Thorenfeld et al. (1987) is here proposed by also considering the coupled behaviour between shear and normal forces at the reinforcement/masonry interface. Numerical analyses are developed with reference to case studies deduced from the literature and consisting of shear lap bond tests of curved masonry specimens characterised by different values of the geometric curvature and different strengthening configurations. The obtained results show the ability of the proposed modelling approach in capturing some effects, such as the beneficial friction effect when compression normal stresses develop at the interface level