Application of 3D DIC Displacement Field Measurement in Residual Stress Calculations

The knowledge of residual stress distribution is of great importance from the viewpoint of both, industrial and basal research. The most commonly utilized method of residual stress determination is based on strain measurements near the drilled holes of known geometry made by means of tensometric rosettes. An alternative to tensometers way of strain measurement is Digital Image Correlation (DIC). This optical method utilizes digital images registered during observed object deformation and delivers results in the form of displacement field maps consisting of hundreds or thousands of data points. Therefore, it is possible to deliver much more data in comparison to rosettes (only 3 or 6 tensometers, usually) and use them in the inverse method numeric procedure for residual stress calculations. In the paper the experimental stand consisting of micro driller and stereo imaging system for 3D DIC measurement and its application to residual stress estimation in prestrained steel samples are presented followed by obtained results discussion.