Masonry walls strengthened with composite materials – dynamic out-of-plane behavior

The dynamic behavior of masonry walls strengthened with composite materials and subjected to dynamic out-of-plane loading is analytically investigated. The analytical model derived in the paper focuses on one-way action through the height of the wall and it is based on dynamic equilibrium and the compatibility conditions between the structural components (masonry units, mortar joints, FRP reinforcement, and adhesive layers). The cracking and the nonlinear and dissipative behavior of the mortar material, the breathing of cracks, the rocking phenomenon, the development of arching forces, the interaction between the existing wall and the composite system, and the formation of debonded zones near the cracked mortar joints are considered in the nonlinear dynamic analysis. A numerical study that examines the capabilities of the model, quantifies the response of the strengthened wall to dynamic loads such as free and forced vibrations and seismic base excitation, and compares it to the response of the unstrengthened wall is presented. A summary and conclusions close the paper.