Patent ID: 6076405
Filing Date: 2000-06-20
Classification: G01H,G01M,G01N

Abstract:
A remote structure monitor, for detecting structural crack beginnings and growth in a rotating metal structure, comprising:a piezo-electric acoustic emission sensor on the rotating metal structure for detecting non repetitive high frequency acoustic emission events of 1 to 10 MHz from stress wave acoustic emission energy that comes from said structural crack beginnings and growth and for converting the acoustic emission energy into electrical signals;a signal processor, connected to said piezo acoustic emission sensor for receiving the electrical signals prom said emission sensor, said piezo-electric acoustic emission sensor being formed from a plurality of piezo-electric layers and a plurality of elastomeric layers situated between the plurality of piezo-electric layers, such that the piezo-electric and elastomeric layers are stacked on one another alternately in that one elastomeric layer is situated between adjacent piezo-electric layers to form a layered sensor;a power storage device being positioned on said layered sensor to provide an inertial load, wherein said sensor outputs the electrical power signals due to compression, stretching and/or bending of the plurality of piezo-electric layers, caused by the vibration of said rotating metal structure and enhanced by said inertial load.