Un metodo automatico per il progetto ottimale del rinforzo di piastre in calcestruzzo armato mediante FRP

The achievement of an optimal arrangement of fiber-reinforcement is a crucial issue for the efficient retrofitting of concrete structural elements. Numerical approaches to the optimal distribution of strips of fiber???reinforced polymers (FRPs) have been recently proposed for in-plane elements, based on methods for the research of optimal load paths that mainly descend from the so-called strut-and-tie modeling. This contribution investigates the adoption of optimization techniques to search for the best distribution of a given amount of unidirectional FRP, along with its optimal orientation, such that the elastic strain energy of a concrete slab to be reinforced at both sides is minimized. Numerical simulations are presented to discuss features of the computed optimal layouts, along with their possible application as preliminary design for retrofitting concrete slabs. The achieved layouts are compared with solutions inspired by the limit analysis theory, which suggests reinforcing slabs perpendicularly to the plastic hinges that arise in the unreinforced elements.