Mechanical characterization of pultruded elements: Fiber orientation influence vs web-flange junction local problem. Experimental and numerical tests

Fiber Reinforced Polymers (FRP) material are proposed and implemented for civil engineering applications for both retrofitting of existing structures and building of new facilities. In new construction realizations, FRP elements are frequently manufactured using pultrusion that represents a high rate manufacturing method, however characterized by a prevalent longitudinal fiber orientation with consequently weakness along the directions different than the longitudinal one. The intrinsic orthotropy, the presence of defects due to the manufacturing processes and the brittle failure mechanisms are peculiarities that decelerate their wide applications, so that are an open issue to be solved. In this regard, the present work experimentally investigates the local behavior of a commercial Pultruded I-shaped Glass FRP (PGFRP) element, in order to: 1) evaluate the mechanical properties of the material according to different fiber orientations, 2) check the validity of the Tsai Hill Criterion and 3) investigate the capacity of the web-flange (WF) junction, that is a recognized weak point, through a novel and simple experimental test.