Comprehensive analysis of glulam delamination through finite element modelling considering heat and mass transfer, plasticity and fracture mechanics: a case study using high density hardwood

With the ongoing emphasis on sustainable and eco-friendly construction, there is a rising demand for high-strength and high-stiffness engineered wood products. This trend presents both opportunities and challenges for the Australia’s hardwood industry, particularly concerning native forest-grown spotted gum ( Corymbia citriodora ). Glue laminated (glulam) spotted gum beams cannot be confidently commercialised due to the difficulty for its high-density to satisfy the bond integrity criteria (referred to as “delamination test”) for external products in accordance with the Australia and New Zealand Standard AS/NZS 1328.1. For in-depth understanding of the delamination process, an accurate numerical model represents a valuable and time-efficient tool. The aim of this study is to develop and detail such a model, considering heat and mass transfer, drying stresses, plasticity and fracture propagation models, using COMSOL Multiphysics 5.5. The model was validated against a series of wetting and drying experiments on spotted gum glulam, considering both moisture content variation and crack propagation along the gluelines. Results from the validated model showed that delamination is principally due to the tensile stress applied to the gluelines.