State-of-the-art review on the web crippling of pultruded GFRP profiles

Web crippling involves the failure of pultruded glass fibre reinforced polymer (GFRP) profiles under transverse concentrated loading. The possible failure modes include web buckling, web crushing and web-flange junction failure, which are very different from those of metallic sections, which are isotropic and yield. This paper provides a comprehensive review of the up-to-date research advancement in web crippling of pultruded GFRP profiles from four perspectives. Firstly, the experimental results available in the literature are summarized and a database is tabulated. Secondly, the factors influencing failure modes and web crippling resistance are analysed, including loading conditions, section geometries, and material properties. Thirdly, recent advancement in numerical modelling is reviewed and paths for improvement are identified. Lastly, analytical models for predicting web crippling resistance are reviewed and their accuracy is assessed by comparing predictions with experimental results from the database. It is concluded that this research area is still in its early stages and more experiments need to be conducted, in a standardized and systematic manner; in addition, more detailed material properties should be characterized for a better interpretation of the failure mechanisms. Accurate and reliable analytical models covering all design cases are not yet available, and most existing analytical models still need to be validated with independent experimental data. Finally, the paper identifies key research gaps and proposes future research directions. This paper also provides a benchmark for the future development of design provisions regarding the web crippling of pultruded GFRP profiles.