Fast and reliable non-linear heterogeneous FE approach for the analysis of FRP-reinforced masonry arches

A simple and reliable finite element model is presented, specifically conceived for the analysis of FRP-reinforced masonry arches. The approach proposed relies on the reduction of mortar joints to interfaces exhibiting a non-linear holonomic behaviour under mixed mode conditions, whilst bricks are discretized by means of four-noded elements remaining linearly elastic up to failure. The FRP reinforcements glued at the intrados or at the extrados are modelled by means of truss bar 2-node elements connecting contiguous nodes of the discretized support, with elastic-brittle behaviour in tension and no strength in compression. The predictions provided by the plane stress model, exploiting also the Italian CNR Recommendations for the engineering practice, are validated against some recent experimental results concerning circular and parabolic masonry arches reinforced by glass and carbon FRP.