A Review of Residual Stress Measurements by HDM and Optical Techniques

Residual stresses occur in many manufactured structures and components. Over the years, different techniques have been developed to measure residual stresses; nowadays the com-bination of Hole Drilling method (HD) with optical techniques is encountering increasing interest. The use of a high sensitivity optical technique instead of the strain gage rosette has the advantage to provide full field information without any contact with the sample by con-sequently reducing the cost and the time required for the measurement. During the years dif-ferent optical techniques have been applied such as moiré interferometry, digital holography and electronic speckle pattern interferometry (ESPI). In the present paper a short summary of the different adopted approaches is provided.