Keywords: unreinforced masonry wall, retrofit, CFRP, GFRP, in-plane, static cyclic loading, numerical analysis.

This paper presents three-dimensional finite element models for in-plane static cyclic behaviour of unreinforced masonry (URM) walls retrofitted using fiber reinforced polymers (URM-FRP). The finite element modelling strategy, based on the concepts of homogenized material with smeared cracking constitutive law for URM walls and orthotropic elastic material with Tsai-Wu failure criterion for FRP, is used in the commercial code ANSYS. Experimental data are used to verify the numerical results and a reasonable agreement is found between the finite element analysis and the experimental results. Then the effects of following parameters are investigated:

• FRP types: glass and carbon
• Various upgrading configurations on one side of URM wall: Full coverage, X, X-Frame, H-Frame, Picture Frame and Reinforced Picture Frame.
• Length/height ratio of the masonry wall: 1:1, 2:1, 1:2.

The results showed the following concluding remarks:

• Retrofitting of a URM wall with GFRP increased the lateral resistances by a factor of 1.1 up to 3.3 and with CFRP increased the lateral resistance by a factor of 1.5 up to 5.3 depending on FRP configuration.
• All the retrofitted models possessed higher stiffness than that of their unretrofitted walls in the static cyclic loading.
• FRPs with high ultimate strain increased ductility and energy dissipation of URM walls.
• X-Frame and H-Frame pattern reinforcement were the optimum configuration that could almost resist against all of the failure modes.
• Retrofitted squat wall represented the most increment of energy dissipation and ductility and retrofitted slender and middle walls represented the most increment in lateral resistance.

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