Structural behavior of hybrid FRP pultruded beams: Experimental, numerical and analytical studies

This paper presents experimental, numerical and analytical studies on the flexural behavior of I-section hybrid fiber reinforced polymer (FRP) beams made of glass fibers (GF) and carbon fibers (CF) pultruded together and embedded in a polyester matrix. A reference profile (all-GFRP) and five series of hybrid C-GFRP profiles, with different types and architectures of CF reinforcement were tested under four-point bending to assess their structural response up to failure. The experimental results confirmed the effectiveness of hybridization in increasing the bending stiffness of pultruded beams. The experimental tests were simulated using finite element models with Hashin damage criterion to study the material progressive failure and delamination. Numerical results showed a good agreement with the experimental data both in terms of loading path and ultimate load. The design approaches of the Italian Guide and American Pre-Standard were assessed, the former being more accurate and conservative than the latter.