| 摘要 |
A structural health monitoring circuit apparatus and method are based on electrical impedance variations of a piezoelectric patch, which is attached to a structure to be monitored. The circuit compares a known good sweep of frequency-impedance pairs with a contemporaneous sweep to generate an alarm when an error bound is exceeded. The impedance of the piezoelectric patch is determined though adjustment of a variable reactance in a bridge configuration. By suitable design of the bridge elements, the electrical impedance of the piezoelectric patch may be directly measured. A microprocessor controlled version of this device consumes less than 2 W of power, which may be further reduced by further large scale integration or reduction to a state machine on a programmable gate array. Ultimately, this device may give personnel warnings to aircraft, automobiles, bridges, elevated roads, buildings, or home structural failures.
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