FREQUENCY METER OF NATURAL TONE OF STRUCTURE OSCILLATIONS AND METHOD OF MONITORING OF AIRCRAFT STRUCTURAL RIGIDITY CHANGE DURING OPERATION Russian patent published in 2020 - IPC G01H1/06 G01M7/02 

FIELD: machine building.

SUBSTANCE: invention relates to machine building, particularly, to determination of resonance frequency and amplitude of resonance oscillations. Proposed oscillator comprises accelerometer and spring. Note here that accelerometer is mounted on spring attached to said structure. Rigidity of spring is selected so that resonant frequency of spring attached to it with sensor attached thereto is equal to frequency of natural tone of oscillations of structure. Also disclosed is a method of monitoring variation of rigidity of aircraft during operation. Method is carried out as follows: first, calculating stiffness of springs, with attached to them accelerometers, resonant frequencies of which are equal to frequencies of 1st, 2nd and 3rd proper tones of bend of main units of structure (under the design here the main units of the design are meant: wing, fuselage, horizontal and vertical fins), then these springs are made and accelerometers are attached to them, which in turn are fixed on the aircraft structure in the following places: in end zones of this unit - in zones of high amplitudes for 1st tone and in zones of antinodes of 2nd and 3rd tones for these tones, then experimentally determining logarithmic decrements of springs with accelerometers attached to them.

EFFECT: technical result of the device and method is high accuracy of determining frequencies of 1st, 2nd and 3rd intrinsic tone of flexural vibrations of aircraft assemblies during operation, from which it is possible to determine deterioration of bending stiffness of the unit with high accuracy.

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