Resonance Characteristics of the Sorption Fiber Optic Piezoelectroluminescent Sensor

Abstract

A mathematical electro-mechanical model of a representative fragment of a gas-analytical optical fiber piezoelectroluminescent sensor with a special external absorption layer for monitoring extended areas has been developed. Informative light signal is generated as a result of mechanoluminescent effect caused by contact interaction of piezoelectric and electroluminescent cylindrical layers (coatings) of fiber in case of forced electromechanical vibrations of sensor under action of applied harmonic control electric voltage. The algorithm for finding the sorption spectrum (changes in the density of the absorption layer along the length of the sensor) is presented through the solution of the Fredholm integral equation based on the results of measuring the informative light spectrum of the intensity of the light at the output from the fiber of the sensor. Numerical solution of coupled stationary boundary value problem of electroelasticity for representative fragment of sensor is implemented. Natural frequencies and shapes of sensor oscillations were found taking into account geometric shape, relative location and anisotropy of electroelastic properties of its structural elements, including characteristics of absorption layer. Regularities of influence of diagnosed value of absorption layer density on informative values of resonance frequencies of different forms of sensor oscillations were revealed.