|
JIAO Jingpin
GE Haiyan
WU Bin
HE Cunfu
College of Mechanical Engineering and Applied Electronic
Technology,
Beijing University of Technology,
Beijing 100022, China
|
|
|
FOULING DETECTION IN FOOD VESSELS
USING INTERDIGITAL LAMB WAVE TRANSDUCER*
Abstract:
Lamb waves are used to detect fouling in food vessels. The propagation of the Lamb waves in plates exhibits many modes and dispersion characteristics, which have great influence on fouling detection. The relative distribution of the in-plane and out-of-plane displacement of the mode across the thickness of the plate will determine the sensitivity of the mode to a particular loading condition. By considering the dispersion and multi-mode characteristics of guided waves, an interdigital polyvi-nylidene fluoride (PVDF) transducer is designed to realize the mode selection of guided waves, and a single a0 mode is used for guided wave detection. Fouling detection experiments are conducted in the laboratory using epoxy adhesive on a thin plate. Using the interdigital PVDF transducer, three fouled areas are detected. Using one of the time-frequency analysis methods, the waveforms are further processed. This also demonstrates the validity of this method of fouling detection.
Key words:
Lamb waves Interdigital transducer Fouling detection |