Development Overview of a Distributed Strain Sensing Technology Using Optical Fiber Sensors for Aircraft Structures
Abstract »Mitsubishi Heavy Industries, LTD (MHI) has been developing a distributed strain sensing technology, named as Brillouin optical correlation domain analysis (BOCDA) especially for structural health monitoring (SHM) of commercial aircraft. This paper reports the eight-year development results of this technology in the Japan-Airbus SHM technology for aircraft composite (JASTAC) project. Optical fiber sensors have great characteristics such as light weight, high corrosion durability, none electromagnetic interference and capability to be embedded into composites. The BOCDA is one of state-of-the-art technologies in distributed sensing technology field, such as long measurement range, high spatial resolution and high sampling rate. Furthermore, it has two unique characteristics comparing with other distributed sensing technologies. Firstly, it measures strain and temperature simultaneously using polarization-maintaining fibers (PMFs). Secondly, you can measure strain at arbitrary points along an optical fiber sensor. The purpose of the JASTAC project is implementation for practical uses of optical fiber sensing technologies, such as the BOCDA. To enhance the technology readiness level (TRL) of the technology, the authors have been verifying and validating durability and detection capability, for instance, durability against assumed chemical, thermal and mechanical environments. Additionally, our system was applied to a full-scale structure test in order to demonstrate the real use case. In this paper, how to go through the verification and validation process was explained using much kind of test results.