Shape design enhancement of pultruded FRP profiles for structures ancillary to masonry constructions

The historical building heritage, monumental, civil and industrial has highlighted, especially in the last decade, the high vulnerability with respect to horizontal actions. The need to design stable and strong structural systems with respect to the stresses acting in various directions has oriented research to develop lightweight technologies for structural systems, independent or ancillary, with reduced mass to mitigate the consequent applied load. In this scenario all-FRP (Fiber Reinforced Polymers) systems can be a valid alternative for new constructions and / or structural reinforcement. The scenario described above, highlights the importance of developing innovative technologies suitable for the functional and structural improvement of the existing buildings. It is necessary to define an innovative approach aimed at identifying an ad-hoc profile for the FRP pultruded profiles (currently referring to the steel shapes), which allows to capitalize the performance capabilities, limiting the main defects related to low shear stiffness of FRP pultruded material. This research analyses how the shape enhancement of the cross sections, with shape redraw, allows to increase the structural performances of FRP pultruded profiles. Experimental data of previous research on buckling behaviour of different open cross section profiles, narrow and wide flanges, have been analysed and validated by numerical approach and compared with new strengthened shapes.