Study on the effect of post curing on the mode II fracture energy of structural adhesive using a parameter identification approach

In this work, a parameter identification approach was developed based on a combined experimental-numerical approach to determine the optimal set of adhesive parameters in adhesively bonded specimen subjected to various post curing treatments. End-Notched Flexure (ENF) testing was conducted to characterise the Mode II fracture property under both recommended and post curing conditions, providing benchmark data for the numerical analysis stage. Experimental results revealed that Mode II fracture energy was effectively affected by the post curing history, with higher temperature and longer curing duration leading to enhanced fracture resistance. The numerically identified Cohesive Zone Model (CZM) parameters using multi-island genetic algorithm provided good correlation in Mode H fracture energies between Finite element (FE) modelling and experimentally measured values, thus extensive experimental characterisation work to determine the adhesive parameters can be effectively eliminated.