Composites are in high demand for many applications; however, fasteners are often required for joining processes. This inclusion of fasteners can provide the necessary joining performance, but the sample preparation (machining) can lead to localized delamination and other stress concentrations requiring increased structural stability and significant added weight. One solution is the use of adhesive bonding, but uncertainty exists regarding long term durability and the ability to interrogate bonds noninvasively. In this paper, a potential solution to qualify bond quality over its service life is proposed. A paste adhesive is doped with magneto-electric nanoparticles (MENs) which can yield magnetic signatures that are dependent on a number of factors within the adhesive bond including adhesive intrinsic material properties and polymer coating level. A key aspect that needs to be evaluated for this novel health monitoring system is the effect of the MENs on the mechanical properties. In this study, adhesives have been doped with MENs prior to bonding at 1% volume concentration. Doped and un-doped polymer coupons were evaluated for magnetic signature, samples were then placed into an environmental chamber to simulate environmental exposure and exposed to ultraviolet lighting. Lap-shear testing was conducted to assess changes in bond strength due to the addition of MENs. Micro-scale end notched flexure (ENF) tests were also conducted providing real time fracture property evaluation. Results from the bond strength and micro-scale sensitivity analysis are presented.
