In this project the environmental degradation of the cohesive strength of adhesives was studied using experiments and numerical simulation.
This work was carried out at the School of Mechanical Engineering with
Thomas H Siegmund.

Adhesive bonding is commonly used in the aerospace industry, and is of special interest as bonding technique if composite materials are employed. Aircraft operate under a wide range of environmental conditions and are subjected to fast changes in climate zones. In this study we investigate the effects of water on the failure behavior of an adhesive joint. To that end, we carry out experiments in which double cantilever beam (DCB) specimens are loaded subcritically but are immersed in water. We continuously monitor the crack extension as the opening of the DCB is increased. Secondly, a coupled diffusion - damage model for cohesive surfaces is proposed and employed in a commercial finite element package to model the experiments. The results predict accelerated crack advance in a moist environments.

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