| Popis: |
This investigation concerns the application of different techniques, including optical fibre strain sensing, pulsed Digital Speckle Pattern Interferometry (DSPI), traditional modal analysis and finite element modeling to the study of vibrating composite structures. A prototype system for condition monitoring of composite structures is being developed which relies on the on-line measurement of dynamic strains in order to detect any deterioration in performance due to the accumulation of damage. A range of carbon-fibre reinforced composite specimens that incorporate innovative Fabry-Perot interferometric long gauge-length strain sensors have been produced and tested. The optimal design of fibre sensor network configurations for the identification of different damage parameters is being aided through the development of a software simulation tool and the use of a p-version FEM package. Vibration modes of the excited structures have also been determined using an out-of-plane pulsed-DSPI system, employing a dual-cavity frequency-doubled Nd:YAG pulsed laser with a 25 Hz repetition rate. In general, experimental results compare favorably with finite element predictions. The data derived from the strain sensors is used to update a parameterized FE model of the composite structure, allowing the determination of the position and extent of damage present.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. |
