FRP-reinforced masonry structures: Numerical modeling by means of a new discrete element approach

The protection of existing historical masonry structures represents a relevant topic in view of the high social and economic values of such constructions. Many strengthening techniques for the rehabilitation of existing monumental structures have been introduced. Some of these strategies are based on the application of fiber reinforced composite materials on the masonry surface. Among these, the application of FRP (Fiber Reinforced Polymers) is a low invasive retrofitting strategy able to improve both the in-plane and the out of plane masonry behaviour applicable to many different structural geometrical layouts. In this paper, by taking advantage of a parsimonious discrete element approach already introduced by the authors, a new strip macro-element for the interaction modeling between masonry elements and FRP reinforcement is proposed. This new element is able to provide a satisfactory simulation of the FRP layer applications toin masonry structures although maintaining a very low computational effort. In the paper, after a theoretical description of the proposed strategy, some numerical applications on case-studies, already investigated in the literature, highlight the capability of the proposed approach to properly describe the collapse behaviour of FRP reinforced masonry structures.