Lightweight Fiber Optic Sensors for Real-Time Monitoring of Structural Health

<strong><i>How It Works </strong></i> The FOSS technology employs efficient, real-time, data driven algorithms for interpreting strain data. The fiber Bragg grating sensors respond to strain due to stress or pressure on the substrate. The sensors feed these strain measurements into the systems algorithms to determine shape, stress, temperature, pressure, strength, and operational load in real time. <strong><i>Why It Is Better </strong></i> Conventional strain gauges are heavy, bulky, spaced at distant intervals (which leads to lower resolution imaging), and unable to provide real-time measurements. Armstrong's system is virtually weightless, and thousands of sensors can be placed at quarter-inch intervals along an optical fiber the size of a human hair. Because these sensors can be placed at such close intervals and in previously inaccessible regions (for example, within bolted joints, embedded in a composite structure), the high-resolution strain measurements are more precise than ever before. The fiber optic sensors are non-intrusive and easy to install&#8212;thousands of sensors can be installed in less time than conventional strain sensors and the system is capable of processing information at the unprecedented rate of 100 samples per second. This critical, real-time monitoring capability enables an immediate and informed response in the event of an emergency and allows for precise, controlled monitoring to help avoid such scenarios. <b><i>For more information about the full portfolio of FOSS technologies, see DRC-TOPS-37 or visit&nbsp;<a href=https://technology-afrc.ndc.nasa.gov/featurestory/fiber-optic-sensing>https://technology-afrc.ndc.nasa.gov/featurestory/fiber-optic-sensing</a></b></i> Innovators at NASA's Armstrong Flight Research Center have developed a lightweight, robust fiber optic sensing system (FOSS) that represents a major breakthrough in sensing technology. The sensors, along with NASA's sophisticated algorithms, can be used to calculate a variety of critical parameters including shape, stress, temperature, pressure, strength, and operational load. This state-of-the-art sensor system is small, lightweight, easy to install, and fast&#8212;it processes information at rates of 100 times per second. For the first time ever, real-time strain measurements can be used to determine the shape of an aircraft's wing, monitor the structural integrity of bridges and pipelines, or ensure precise placement of the tiniest catheters, to name just a few potential applications.