STRUCTURAL HEALTH MONITORING SYSTEM EMPLOYING ELECTROMECHANICAL IMPEDANCE TECHNOLOGY

摘要

A method to acquire the structural health state of an aircraft mechanical component performs measurements at each frequency point of interest by using a network of transducers and working each one simultaneously as actuator and sensor. Each transducer is individually excited by a sinusoidal, constant frequency and arbitrary amplitude, voltage waveform for each arbitrary frequency point used to interrogate the structure. A dedicated hardware executes an analogical (analog) quantization to measure electrical current and average electrical power consumed by each transducer. With these two variables, the electromechanical signature of the structure is obtained at different areas of the monitored structure.

主权项

1. A method for acquiring the health state of an object or a structural component using an EMI technique by performing measurements at each frequency point of the interest bandwidth by using one or more piezoelectric transducers operating as sensors/actuators at the same time, the method comprising:
a. providing sine wave excitation, at both constant frequency and amplitude, for each frequency point of interest; b. analog quantizing the RMS circulating current and the average consumed power of the transducer in order to directly measure the resistive part of the electromechanical impedance; c. compensating for environmental effects; and d. compensating for static and dynamic loading; e. wherein the method uses only one transducer to monitor the health state of a pre-determined area of an object or structure.