METHOD OF IMPACT MEASUREMENT ON FASTENING STRUCTURE OF AIRCRAFT ON-BOARD EQUIPMENT AT PRESENCE OF VIBRATION AND IMPACT LOADS IN MEASURED PROCESS

摘要

FIELD: measuring equipment.;SUBSTANCE: invention can be used for measuring impact loads on aircrafts. The method includes measurement of total vibration and impact measurement processes f total vibration and impact process in places of on-board equipment placement at wing ends and end parts of aircraft fuselage, with the use of transducers, which sensitive elements respond to acceleration arising at the area of attachment of these transducers, its recording to the recorder. In addition, total measurement information is processed first to obtain the measured amplitude spectrum in the given range from the lower frequency to the upper frequency. The cut-off frequency is calculated according to the preset requirement in the technical setting for the development of the software based on reference impact with the duration and amplitude spectrum described by the known analytical expression beyond which the amplitude spectrum is equal to 0. Then frequency with maximal value of amplitude spectrum is selected within the range in measured amplitude spectrum. Frequency is identified with estimated frequency value. For this frequency, the ordinate of amplitude spectrum of reference impact is calculated according to the known analytical expression for that spectrum in relative values, the acceleration amplitude of the measured impact is calculated, and then the calculated value of impact amplitude is compared with the given amplitude value of the reference impact. A condition must be met: the amplitude of reference impact should be greater than the amplitude of the measured impact, and obtained mismatch between experimental and preset amplitude values is compared with permissible value. An impact whose amplitude spectrum is described by the analytical function of a semi-sinusoidal, rectangular or triangular shock can be given as a reference.;EFFECT: increased reliability of determination of impact parameters on the fastening structure of the aircraft on-board equipment, simplified processing procedure and significant reduction of the time for analysis of the results.;2 cl, 5 dwg, 2 tbl