Progressive damage analysis of pin bearing failure in GFRP using continuum shell FE modelling approach

Abstract

Pin-bearing is a favourable failure mode in bolted glass fiber reinforced polymer (GFRP) joints because itoffers quasi-ductile behaviour due to complex failure mechanism involving: matrix cracking, fibre fractureand delamination. Such complexity brings the challenge in prediction of failure through FE modelling withstate of the art studies mostly being limited to very small joint geometries due to large computational costsof very detailed 3D models. Aim of this study is to show the applicability of an efficient modelling approachfor analysing complex model geometries in structural engineering applications and to understand its failuremodes. In the applied modelling technique, the laminate is represented by a series of continuum shellelements, while cohesive interaction property with bilinear constitutive law is defined between the sublaminates to capture delamination failure. The FE model built in Abaqus/Explicit is calibrated to loaddisplacement curves of double-lap single-bolted joints. A calibration methodology is developed incorporatingthe effect of the number of elements in thickness direction on the bearing response of the laminate. Residualbearing strength of the elements subjected to matrix compression, which is not captured by the inbuiltdamage model, is achieved by the modification of maximum damage index. The modelling approach provedto be computationally efficient, while capturing all relevant failure modes, and replicating damage patternsof the specimens, therefore it can be recommended for larger scale FE models.