Reliability analysis of pultruded GFRP I-sections subjected to lateral torsional buckling ultimate limit state

Resumo

Pultruded Fiber-Reinforced Polymers (FRP) profiles are innovative structural elements with outstanding mechanical properties, combined with economic viability. As some interesting properties of that material, it is possible to mention: its corrosion resistance, thermal insulation, high impact resilience, superior strength to-weight when compared to conventional civil industry materials like steel and aluminum, and cost-effective manufacturing processes. Nevertheless, studies regarding the effects of the heterogeneity of elastic and mechanical properties, due to the pultruded FRP profiles manufacturing process, on the reliability of those structural members under common loading conditions are scarce on the literature. So, in this sense the present work compares reliability analysis results of global buckling ultimate limit state of I-section pultruded beams, considering fiber-resin content uncertainty under homogeneous distribution and by considering the spatial variability of these properties using gaussian random fields. First Order Reliability Analysis (FORM) method and Monte Carlo Simulation (MCS) with Latin Hypercube Sampling were employed to calculate failure probabilities of pultruded FRP profiles under global buckling limit state. Buckling loads estimates were obtained by eigenvalue buckling finite element analysis. In order to reduce computational cost of the FEM models gaussian process metamodels were employed.