Residual Stress Measurement with ESPI Hole Drilling Method

Image of ESPI assisted hole drilling method

A technique widely used for determining macroscopic, near-surface residual stresses is the hole drilling strain gage method. The relaxed surface strains are measured during drilling of a small hole into a component using a three-element strain gage rosette. The residual stress is estimated from the strain relief using various prediction models based on the theory of elasticity. An enhancement of the semi-destructive hole drilling technique towards optical measurement of the strain relaxations by electronic speckle pattern interferometry (ESPI) is promising.

Recording the in-plane displacement field around the drilling hole by a non-contacting optical method instead of the commonly used stain gage technique provides an increased amount of data, less instrumentation effort, and a reduction of systematic measurement errors, including the error of misalignment of the drilling axis to the strain gage centre.

Download Application Note

More Information

To learn more about how Dantec Dynamics can help you solve your testing challenges, contact us today