Optical hole drilling method for determining residual stresses from recordings of surface of workpiece before and after drilling operation

摘要

Initially three dimensional images of the workpiece to be investigated are recorded using two CCD cameras. A hole or holes are then drilled in the area under investigation in sequence, simultaneously, in stages or in one operation. With the aid of computers from a comparison of the images the resultant dislocations are established from which residual stresses can be derived. The process can be facilitated by using optical object scanning in which geometrical or random optical patterns are superimposed on to the surface.