METHOD OF DETERMINING INTERNAL RESIDUAL STRESSES AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2020 - IPC G01B9/02 G01B11/16 

FIELD: measuring equipment.

SUBSTANCE: invention relates to measurement equipment and method of determining internal residual stresses. Method includes illumination of surface with radiation of laser scattered on reference and object beams, formation of speckle-interferograms by subtraction of recorded on video camera frames obtained before and after performing probing blind hole, and determination of residual voltage value based on results of counting number of interference bands with accuracy of one interferogram band upwards. To increase the accuracy of measurements, two speckle interferograms are formed from lasers with different wavelengths of radiation and regions of intersection of spread of values determined by two speckle interferograms of residual stresses with allowance for absolute error are found. Lower boundary of the intersection area is taken as the nominal value, and the value of the intersection area as the absolute error of the residual voltage in the magnification side from the nominal value.

EFFECT: technical result consists in reduction of measurement error caused by discreteness of measurement of residual stresses when counting interference fringes.

11 cl, 7 dwg