FIELD: measuring instruments.
SUBSTANCE: oscillations are discretely excited in flight at a lifting surface under study within the range of its self-oscillation frequencies. At the same time bending and torsion oscillations are measured therein and their cross-correlation function based on real-time correlation and a ratio between them during the observation period are determined. The moment of appearing of a crack or a puncture hole, as well as the admissible flying speed of the aircraft in presence of damages is determined basing on the comparison between actual values of the self-oscillation frequencies and reference values. The device consists of an aircraft lifting surface, a pulse oscillation generator and a bending oscillation sensor. Moreover, the pulse oscillation generator is mechanically connected to the lifting surface under study, whereon bending oscillation sensors are disposed. The device is additionally provided with torsion oscillation sensors, a correlator, a multiplier, an integrator, first, second, third and fourth AND-gates, a memory unit, a divider, an indicator, first and second shift registers, first, second, third and fourth AND-NOT gates, a pulse generator, first and second counters and a subtractor.
EFFECT: capability to determine the moment of damage appearing in the stricture of an aircraft in flight and to determine the admissible flying speed for a lifting surface in case of a crack or a puncture hole appearing thereon.
2 cl, 1 dwg
