Experimental Mechanics for Multifunctional Composites and Next Generation UAVs

Low-cost unmanned aircraft that use affordable manufacturing and have limited service life can enable mission concepts in which there is a higher tolerance for aircraft loss, or attrition. Because of their higher risk tolerance, these low-cost attritable aircraft could also integrate emerging technology which may have previously been considered too risky for integration into expensive and long life aircraft. Light-weight multifunctional structural composites have the potential to integrate additional functions and enable mission agility without significantly adding weight or reducing payload capacity. However, design and development of these material systems are often difficult because of the traditional “building block” development approach used for traditional composites, the large option space available for structural and functional properties, and the potential complexity of the multiscale and multiphysics coupling. To realize integrated functionality, new multi-scales and multi-physical experimental mechanical characterization techniques should be merged with maturing integrated materials models. We discuss this need using examples of a reconfigurable liquid metal Structurally Embedded Vascular Antenna (SEVA), a plasmonic nanoparticle based method for measuring internal temperature gradients, and embedded micro-cantilever carbon-nanotube based sensors. The latter of these is also used to discuss the potential to accelerate development of multifunctional structural concepts by provide air flow measurement and structural feedback during testing of complex structures. This could, in turn, eliminate some testing of intermediate elements in the slow and expensive traditional “building block” approach.