Directional GUW emission and sensing systems in fibre metal laminates

• Applicants: Professor Dr. Andreas Dietzel; Professor Dr.-Ing. Björn Lüssem; Professor Dr.-Ing. Michael Sinapius
• Subject Area: Microsystems ; Lightweight Construction, Textile Technology
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 418311604

Within the Research Unit FOR3022, subproject 2 is concerned with the observability and excitation of guided ultrasonic waves (GUW) and their interaction with internal damage inside fibre metal laminates (FML) for damage detection and classification. The general aim is to increase the information density and energy efficiency in wireless structural health monitoring systems for FML. The research approach is the combination of the potentials of three research fields. First, novel wirelessly operated and evaluated MEMS sensors with multi-axis sensitivity will be developed by WG Dietzel to independently observe in-plane and out-of-plane components of the occurring GUW in a single sensor. Glass-silicon based MEMS sensors are ideally suited for low-interference integration due to their adapted acoustic properties, their very small dimensions and their flexibly selectable geometry. MEMS sensors have a high sensitivity and are suitable for multidimensional acceleration fields. Second, the technique of embeddable phased array transducers will be extended by WG Sinapius for anisotropic and inhomogeneous materials such as FML to enable directional GUW excitation and sensing and thus increase the energy efficiency and information density, respectively. The structure-compliant interlaminar embedding of the sensor nodes for acoustic damage detection in FML is the object of research by WG Sinapius. Third, novel approaches in wireless power transfer concerning resonant circuits will be adapted by WG Lüssem for energy and signal transmission to emit GUW in FML wirelessly. In combination, these components are the key to exciting and observing wave propagation inside fibre metal laminates as a basis for automatic identification and classification of structural damage.

• DFG Programme: Research Units
• Subproject of: FOR 3022: Ultrasonic Monitoring of Fibre Metal Laminates Using Integrated Sensors
• Major Instrumentation: Pico-scale Scanning Laser Doppler Vibrometer
• Instrumentation Group: 5750 Spezielle Laser-Mess-Systeme (z.B. Laser-Doppler-Vibrometer)