PROCEDURE PREDICTING RESIDUAL SERVICE LIFE OF STEEL STRUCTURES Russian patent published in 2002 - IPC

FIELD: analysis of state of steel structures of mechanical systems, mining machines, in particular. SUBSTANCE: according to procedure residual service life of steel structures is achieved by determination of spectral density, temporary tensile strength, yield point, relative reduction and elongation, friction angle of structural inhomogeneities of natural roughness. Standardized spectra of resonance are determined in five ranges of response frequencies of acoustoemission radiation: ultrasonic oscillations of subgrain in range 62,7-19.1 kHz, oscillations of shear- detachment in range 2.7-1.9 kHz, modulating relaxation twinning oscillations in range 432-82 Hz, modulating relaxation oscillations of structural hardening in range 50.2- 17.85 Hz and modulating relaxation oscillations of infrafrequency in range 4.6-4.2 Hz. All mentioned physical and mechanical parameters are established for moment of total degradation of metal and for time T_i, of measurement, then residual service life ΔT_п, is found by certain formula that includes recorded time of usage and values of diameters of metal subgrains. EFFECT: prediction of residual service life without any repeated measurements. 2 cl, 1 dwg