METHOD FOR DETERMINING GENERALISED PARAMETERS OF OSCILLATIONS OF STRUCTURES BY FREQUENCY CHARACTERISTICS Russian patent published in 2021 - IPC G01H7/00 

FIELD: measuring.

SUBSTANCE: invention relates to determining the generalised parameters of the natural tones of oscillations of structures based on the frequency characteristics (FC) measured experimentally. In implementation of the method, the structure is fixed in space, vibration exciters and vibration sensors are attached to the structure, modal testing is conducted using a multi-channel system for control, excitation and measurement of harmonic oscillations by the method of phase resonance of each tone, in the process whereof, the frequency characteristics of forced oscillations are measured in the vicinity of the phase resonance of each tone, generalised masses, generalised damping, and generalised stiffness of the natural tones of the oscillations are determined. Force sensors are therein installed at the points of excitation of oscillations of the structure, connected with the vibration exciters, the frequency characteristics are determined according to the signals from the vibration sensors and force sensors at the points of excitation in the vicinity of the phase resonance of each tone of oscillations. In order to calculate the generalised parameters, the real part of the frequency characteristic of the dynamic stiffness of the structure is used, according whereto, the generalised masses and stiffnesses are calculated depending on the square of the circular frequency, applying linear interpolation of a sufficiently large number of points, and the imaginary part is used to calculate the generalised damping.

EFFECT: increase in the accuracy of calculations and reduction in the labour intensity of determining the generalised masses, stiffnesses and damping characteristics of the natural tones of oscillations.

1 cl, 4 dwg