Patent ID: 6078396
Filing Date: 2000-06-20
Classification: G01B,G06T

Abstract:
A method of analysing out of plane deflections in materials under load, comprising the steps of:i) projecting onto a material specimen under analysis a grating;ii) using a CCD colour video camera to capture frame by frame images of the material specimen and associated grating lines projected thereon, where said image of said projected grating lines has a pitch substantially equal to the distance between adjacent pixels of the same color on said CCD color video camera in a direction perpendicular to the grating lines, whilst the material specimen is undergoing deflections due to loading by sequentially recording and storing the information relating to each colour channel of the colour video camera in a frame store;iii) analysing the recorded images of the material and associated projected grating lines thereon by selecting recorded information from pairs of colour channels in turn, so as to create the effect of an imaginary grating interferingly superimposed on the projected grating; and,iv) deriving from said analysis intensity and phase data corresponding to the out of plane deflections of the material at sequential times.