Frequency Selective Surfaces for Passive, Unpowered, Wireless, and Non-Contacting Softgood Structural Health Monitoring

A key enabling technology for the future of crewed habitation systems is developing inflatable softgood materials and structures to provide larger habitat volumes with a lower structural mass.‚ÄØNASA requires technologies to mature inflatable softgoods via integration of sensing capabilities for structural health monitoring (SHM) for deployment of these devices as part of future space habitation systems.‚ÄØ Texas Research Institute (TRI) Austin and The Missouri University of Science and Technology (MST) propose the development of frequency selective surface (FSS)-based structural health monitoring capabilities for inflatable softgood material systems to monitor the structural performance of these materials in situ.nbsp; This technology provides the ability to measure load/strain on softgood components, detect damage, and potentially predict further degradation/potential failures via a non-contacting, passive, and unpowered system.‚ÄØ TRI and MST will couple this technology to a commercial-off-the-shelf vector network analyzer to allow NASA to acquire, process, and make use of this data in real time as an important risk mitigation mechanism for potential structural failure modes.‚ÄØ In Phase I, TRI and MST will demonstrate the validity of this system via proof of concept and preliminary testing on representative inflatable softgood structures in the creep strain range of interest (0.1-0.5% strain, or 1,000-5,000 microstrain).‚ÄØ This technology can be incorporated into softgood structures as either a ldquo;stand alonerdquo; add on (built on a substrate and implanted/adhered into the layer of interest in the structure), or as a ldquo;built inrdquo; piece of the inflatable (such as by using conductive textiles), as the FSS can be illuminated and the response designed specifically to transmit through a dielectric material, or a series of dielectric materials.nbsp;