| Abstract | Properly deployed Structural Health Monitoring (SHM) has the potential to benefit the design, operation and maintenance of aircraft. For current aircraft, SHM could help extend operational lives while reducing operational (and maintenance) costs and increasing availability and operational safety. In addition, the implementation of SHM during the design stage of new aircraft could result in weight reduction through optimized design and the incorporation of active safety measures. However, a significant level of development, testing and demonstration is still required for SHM systems to attain the required maturity for deployment on ground and flight tests, and operational aircraft. With this intent, the National Research Council of Canada (NRC) has created a global framework, complete with a set of structural platforms facilitating an accurate assessment, development and demonstration of SHM systems. These platforms, with increasing levels of structural complexity, can accommodate SHM systems at different Technology Readiness Levels (TRL). The first level of structural complexity presents a simple 2 m long aluminium beam, with solid, rectangular cross section, the behaviour of which is well characterized through analytical and numerical methods. The second platform presents a slightly increased structural complexity, consisting of a typical representative 2 m long aircraft wing skin with riveted z-stringers, containing two different aluminium alloys. The third level of complexity presents a hybrid material aircraft wing box representative structure, with internal aluminium structures and carbon fibre reinforced epoxy composite skins. The final platforms consist of a full scale CF188 aircraft wing and a Bell 407 helicopter tail boom, representative of the current aerospace structures to trial sensors and measurement systems. In all of these platforms, representative load conditions applied during full scale tests or observed during flight operations can be applied through the use of several hydraulic actuators and actuation configurations. These load conditions range from static and quasi-static bending, torsion and coupled load conditions, to low frequency cyclic loading (either constant amplitude or operational spectra) and higher frequency vibration associated with buffet and flutter. Beyond the assessment, development and demonstration of load monitoring techniques and sensor systems, these platforms also offer the opportunity for the development and assessment of SHM techniques and systems capabilities to detect and monitor damage growth. In order to assess the TRL of the different SHM systems, replaceable components are introduced, either in a pristine condition, or with existing or artificially introduced representative damage, which can be grown during the application of the testing loads. Furthermore, these test platforms are being prepared to introduce representative flight operation environmental conditions, such as temperature and humidity. |
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