Abstract: | The strain gage hole drilling method is the most widely used residual stress measurement method. However, for sheet metal formed parts this method is less suited because of small thickness of the sheet metal and, generally, non-uniform stress distribution in the thickness direction. Consequently, for residual stress measurement is proposed a method based on trepanning of small round pieces from formed part and strain determination by digital image analysis. Also, using digital image analysis, the field of displacements and strain in analyzed area may be determined. |