FIELD: physics; measurement.
SUBSTANCE: present invention pertains to construction, particularly to non-destructive control methods and integral evaluation of the quality of pre-cast concrete structures when making them. The method involves putting the structure onto a stand, fastening its ends in accordance with operation conditions, fitting a mechanical oscillation receiver and an oscillator at opposite surfaces of the structure (in the middle of its superstructure) for generating and recording bending mechanical oscillations. After that, the structure is loaded with a static uniformly distributed load and, using a generator of sinusoidal oscillations and a power amplifier, oscillations are generated in the required frequency range. The energy of these oscillations is kept on a strictly defined level. Using a spectrum analyser, the amplitude-frequency curve is plotted for the test structure and the resonance frequency of the oscillations is determined from the curve. Spectral analysis of the oscillation process is done at this resonance frequency at the energy level of generating longitudinal or transverse oscillations of the structure. The first four amplitudes of oscillations are determined and the non-linear distortion coefficient is determined from it. The degree of defectiveness of the structure is determined from the value of deviation of the non-linear distortion coefficient of the test structure from the corresponding value of this coefficient for a standard structure.
EFFECT: increased information content and accuracy of obtained integral quality evaluations.
2 dwg
