Web-crippling behavior of pultruded GFRP I-section beams under one-flange loading: Computational modelling and parametric study

This paper develops and validates a computational model to investigate the web-crippling behavior of pultruded glass fiber-reinforced polymer (GFRP) I-section beams under end-one-flange (EOF) and interior-one-flange (IOF) loading conditions. First, the geometry and material properties of the specimens are briefly introduced, followed by a detailed description of the shell finite element-based model. The model is then validated against recent test data, showing good agreement with experimental failure modes, load-deflection responses and strain distributions, thereby demonstrating its accuracy and reliability. Finally, the validated model is used to systematically explore the influence of some key parameters that have not been thoroughly studied or have never been examined, namely the threshold distance between loaded and support sections ( D ), web slenderness ( H / t ), flange restraint, and bearing plate material. The study of these parameters aims to provide valuable insights for future design and engineering applications. The results indicate that web slenderness, flange restraint and FRP plate thickness have a significant impact on resistance and failure patterns; in particular, flange restraint increases load capacity by up to approximately 42 % under EOF and 24 % under IOF conditions, depending on the bearing length. In addition, a more appropriate parameter for defining the threshold distance was found to be the web slenderness ratio ( H / t ). For the geometries of GFRP profiles currently available on the market (with web slenderness, H / t = 152 mm/6.3 mm ≈ 24.1), it is recommended that no threshold distance be defined, at least in the case of internal flange loading. • Computational modelling and parametric study of web crippling of pultruded GFRP beams under one-flange loading. • Definition of minimum threshold distance for distinguishing one- and two-flange loading in GFRP beams. • Effects of web slenderness, flange restraint, and bearing plate material on resistance and failure patterns.