Investigation of the mode I fracture properties of adhesively bonded joints after water ageing
Abstract
To investigate the mode I fracture properties of adhesively bonded joints after water ageing, the authors reduced here the width of Tapered Double Cantilever Beam (TDCB) specimens to 5 mm (compared to typical values encountered in literature at 10 mm). This was decided in order to reach the desired water absorption levels within a reasonable time. However, this operation was found to increase the impact of the edge effects on the fracture results, which were illustrated by finite element simulations. Hence, to improve consistency and stability of crack propagation, special beaks were added on the surfaces of the substrates close to the adhesive layer, based on previous solutions implemented for Arcan specimens. The results showed that the fracture energy decreased very rapidly to about half of its initial (unaged) value, and remained almost constant for all water ageing times that were examined in this work (4, 8, and 12 months).