Pultruded Glass Fiber-Reinforced Polymer Composites under Eccentric Compression Loading

Glass fiber-reinforced polymer (GFRP) composites have emerged as alternative materials for building applications, and one common loading scenario for GFRP members in building structures is eccentric compression. This compression may occur due to the locations of these members in structures or shapes of their cross sections, causing compressive loads not in alignment with the centerlines of these members. Under this loading scenario, the shear stresses induced by second-order effects may lead to shear and delamination failure prior to compressive or tensile failure due to the low shear strength of GFRP composites compared with their compressive and tensile strengths. This paper presents a study on pultruded GFRP laminated plates subjected to eccentric compression loading, including experimental investigations, numerical modelings, and analytical derivations, with a focus on the effects of the slenderness of the GFRP plate and the eccentricity of the compression load on their failure mode and compressive capacity. Two types of failure mode were observed from the experiments. One was compressive/tensile failure mode, the other was shear and delamination failure mode. In a coordinate system with slenderness as the horizontal axis and eccentricity ratio as vertical axis, zones for shear failure and compressive/tensile failure were identified and a curve that delineates the two zones was developed. Furthermore, predictions of shear and delamination failures based on the results obtained from numerical and analytical studies were presented and compared with the actual failure observed from the experiments.