The
effect of the supporting conditions on the overall and the localized
out-of-plane behavior of un-reinforced masonry (URM) walls strengthened with
externally bonded composite materials is analytically investigated. Four
combinations of supporting conditions with different restrictions of the
longitudinal elongation and rotation are examined. These cases reflect some of
the possible realistic supporting conditions that may exist in practical
applications. A theoretical model that is based on variational principles,
equilibrium equations, and compatibility requirements between the structural
components (masonry, mortar, FRP, adhesive) is used for the investigation. The
effect of cracking of the mortar joints and the interaction of the existing
wall with the composite strengthening system through the adhesive layer are
considered. The results reveal the critical influence of the various supporting
conditions on the response of the strengthened wall and shed some light on
aspects of the design of the externally bonded strengthening system.