FINITE ELEMENT APPROACHES TO ANALYZE FRP STRENGTHENED MASONRY STRUCTURES

Masonry structures have always been used since the dawn of construction, and nowadays, due to aging, material degradation, settlements, and structural alterations, usually some members need strengthening to re-establish their performances. In this frame, fiberreinforced polymer (FRP) composites can be a viable solution, provided they comply with the cultural value of the building. In the first part of this work, numerical approaches to model FRP strengthend masonry structures are discussed and in particular a material model suitable for micro-modelling of the FRP-masonry interfacial behaviour implemented in the Diana FEM program is presented. This micro-modeling approach based on interface elements is then used to develop and validate the global behaviour of a different type of Finite Element that was implemented in the Opensees framework. This new element is extremely effective for the seismic analysis of masonry buildings because it drastically reduces the number of degrees of freedom of the FEM model. Numerical results are validated by comparison to experimental results from tests performed at the University of Pavia and the Georgia Institute of Technology. In particular, it shows a satisfactory degree of accuracy at the global level, and is efficient enough, to analyze complex assemblages of masonry buildings including cyclic load effects and FRP strengthening.