A new real-time polarimetric method for determining the distribution of stressed state in different constructions

摘要

A new real-time nondestructive polarimetric method is suggested for the determination of the stressed state distribution in different objects. Light reflected from the object is polarized in a varying degree, and the distribution of the polarization state in the object image is related to the distribution of stresses in it. Method is based on the obtaining the distribution pattern of the polarization state of light in the object image, which is formed by an objective. The integral polarization-holographic diffraction element developed by us is used for real time complete analysis of the polarization state of light at each point of the image, formed by the element in the diffraction orders. The simultaneous measurement of the intensities in four diffracted beams by means of a matrix of photodetectors and the appropriate software enable the polarization state of an analyzable light and its change to be obtained in real time. The laboratory model is presented. The correlation relations between the polarization state of light reflected from the sample with the distribution of the dosated mechanical stresses is considered. The theoretical model is presented. The experimental results are shown for different samples with one- and two-axis stress distribution. The method is nondestructive, i.e. there is no need to drill holes or openings or sticking transparent photoelastic plates on the object to determine the stresses. This method will enable the distance monitoring and diagnosis of already existing constructions to be carried out. This method will differ by universality, simplicity, high speed and comparative cheapness.