Evaluating healing behavior of thermoplastic adhesive bonded joints subjected to transverse impact loads

Impact loads transferred to the bond-line of adhesive joints can significantly decrease their load carrying capacity. If the damage in the adhesive layer can be healed, such losses in structural behavior can be recovered. One such healing technique is the use of thermoplastic 'reversible' adhesives which are reinforced with conductive nanoparticles. Such materials have been shown to heal through exposure to electromagnetic fields. In this work, single lap joints were manufactured using ferromagnetic nanoparticle reinforced ABS thermoplastic polymer as the adhesive. The joints were tested under quasi-static tensile loading to determine their baseline performance. Similar joints were then subjected to impact load (10 J) to induce bond-line damage. Impacted joints were subjected to quasi-static lap-shear to obtain impact-induced performance. Next, the impacted joints were subjected to electromagnetic fields to heal the damaged adhesive and then subjected to quasi-static lap-shear tests to obtain the healed performance. The loss in joint strength due to impact, and its subsequent recovery due to healing was evaluated.