Temperature and strain sensors designed by HRL Laboratories can be embedded during additive manufacturing for wireless structural health monitoring.
MALIBU, Calif. July 23, 2024— HRL Laboratories, LLC, has launched the Wireless Sensing of Strain and Temperature (WISEST) project under the Defense Advanced Research Project Agency’s (DARPA’s) Structural Evaluation through Non-contact Sensor Embedding (SENSE) program. The goal is to monitor stress and temperature in critical components of vehicles to detect damage that could aid in forecasting potential failure events. Monitoring locations that are difficult to access during operation is a challenge, and depending on the operating environment, sensors placed on the surface will not likely survive. Additive manufacturing technology enables embedding the sensors inside a part during component fabrication, placing the sensor near high stress locations that require monitoring while also protecting the sensor from the harsh operating environment.
“Laser powder bed fusion enables embedding sensors during additive manufacturing in strategic positions to acquire data at or near potential failure points,” said Dr. David Shahan, program manager at HRL Laboratories. “This program builds on HRL’s experience with wireless stress and temperature sensing to measure and monitor important data in a way that’s never been done before.”
“We will develop sensors that can be read out wirelessly using magnetic fields, ensuring full protection from the external environment and avoiding the need to run wires through the component,” said Dr. Gavin Chang, senior scientist at HRL Laboratories.
One example for application of this new technology is in-situ fatigue assessment in rotorcraft transmission housings. Boeing recently demonstrated 3D printed transmission housings for a CH-47 Chinook helicopter. High loads, cyclic stresses and elevated temperatures make these critical components prone to fatigue cracks. The technology developed under this program will embed sensors close to where parts are predicted to be limited by fatigue cracking. The sensor stress and temperature data will enable early identification of high risk for crack initiation. Given this information, it will be possible to schedule maintenance on an as-needed basis, resulting in lower maintenance costs for a fleet of vehicles.
HRL will collaborate with the University of California at Irvine. Prof. Lorenzo Valdevit’s research group will perform simulations to optimize sensor element integration and sensing range.
HRL Laboratories, LLC, Malibu, California (hrl.com) is a research-and-development laboratory owned by The Boeing Company and General Motors specializing in research into sensors and materials, information and systems sciences, applied electromagnetics, and microelectronics. HRL provides custom research and development and performs additional R&D contract services for its LLC member companies, the U.S. government, and other commercial companies.
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