Dynamic model of control of vibration damping mode by fiber optic PEL-sensor with phase shifting of control electric voltage.

A mathematical dynamic model of the operation of the vibration pressure optical fiber piezoelectroluminescent (PEL) sensor in the damping mode was developed taking into account the electrical conductivities and Maxwell-Wagnerian relaxation of electric fields in the phases for the case of harmonic stress (vibration pressure) on the external cylindrical surface of the sensor. Analytical solution of damping of stationary axisymmetric oscillations of optical fiber PEL-sensor is obtained and investigated by applying coherent control electric voltage to electrodes of sensor with phase shifting relative to vibration pressure. Regularities of frequency dependencies for real, imaginary parts of control, informative transfer and damping coefficients of sensor are established and studied. Analysis of influence of value and shift angle of phases of control electric voltage on results of numerical simulation for intensity of light flux at output from optical fiber of sensor under action of vibration pressure is performed. Frequency dependencies were found for the electrical impedance of the AC electric circuit of the sensor in comparison with the approximation of these dependencies by electromechanical analogy. It was revealed that in the frequency range under consideration, the electrical impedance of the sensor with satisfactory accuracy is based on consideration of an equivalent electric circuit with parallel connection of frequency-dependent active and capacitive elements. Frequency range and values of control parameters are set for effective active damping of vibration pressure through conversion to Joule heat (dissipation) of mechanical energy supplied to the sensor. The results of comparing the analytical and numerical (in the ANSYS package) approaches confirm the validity and adequacy of the decisions obtained.