Progressive Damage Analysis of Web Crippling of GFRP Pultruded I-Sections

Glass fiber–reinforced polymer (GFRP) pultruded profiles are prone to web buckling and/or crushing when subjected to concentrated loads in the direction transverse to the pultrusion axis due to their low elastic and strength properties. Based on a recent work in which it was concluded that the Tsai-Hill criterion does not succeed in providing reasonable estimates of the web-crippling capacity of GFRP profiles, in the present work another progressive damage model is implemented into a finite-element (FE) model for web-crippling analysis. First, previous web crippling experiments on I-section GFRP profiles are summarized. Then the basis of the FE model is presented (element types, failure initiation criteria, and damage model) and results of preliminary analyses (mesh size and viscous regularization) are discussed. Subsequently, the load versus displacement curves, damage zones, and failure modes of GFRP profiles under different load configurations and bearing lengths are presented. Finally, the model sensitivity to different parameters (transverse compressive strength, in-plane shear strength, matrix compressive fracture energy, modeling of web-flange rounded corner) is analyzed. The proposed model is shown to be much more accurate than those based on Tsai-Hill criterion. It is also shown that the in-plane shear strength governs failure initiation, while the transverse compressive strength is more influential to the profiles' ultimate behavior. This study also highlights the major impact of fracture energy in the behavioral response of GFRP profiles subjected to transverse concentrated loads.