Self-sensing Adhesive for Monitoring Composite Bonded Joints

Statement of Work Adhesive bonded joints offer a number of advantages over bolted joints and are widely used in aerospace structures. However, inspection of debonding in the adhesive remains a critical concern. This project will address the development of a self-sensing mechanism to monitor the health of composite bonded joints. Nano fillers, such as single-walled and multi-walled carbon nanotubes (CNTs), integrated within the adhesive, will be used to improve the mechanical and electrical properties; the piezoresistive property will be exploited for in-situ monitoring of the structural integrity of the joint. Although preliminary work has been reported on the development of self-sensing capabilities in composite adhesive joints [1-3], several issues remain to be addressed. This project will address the following tasks. 1. Develop of self-sensing capabilities in composite adhesive joints using single-walled and multi-walled CNTs. 2. Investigate sensing performance under complex loading conditions, such as impact and fatigue. 3. Study the effects of local agglomeration on the self-sensing capability. 4. Validate the use of CNT integrated self-sensing epoxy in complex joints (such as stiffened structures). References 1. Liu, Y., Rajadas, A., and Chattopadhyay, A., A biomimetic structural health monitoring approach using carbon nanotubes, JoM: The Member Journal of TMS, Vol. 64, No. 7, pp. 802-807, 2012. 2. Gibson, R.F., A review of recent research on mechanics of multifunctional composite materials and structures, Composite Structures, Vol. 92, pp. 2793-2810, 2010. 3. Thostenson, E.T., Chou, T.W., Carbon nanotube networks: sensing of distributed strain and damage for life prediction and self healing, Advanced Materials, Vol. 18, No. 21, pp. 28372841, 2006.