Measurement of residual stresses using a radial in-plane digital speckle pattern interferometer and local heating. Recent advances

This paper presents an application of a radial in-plane digital speckle pattern interferometer and a local heating combined system to measure residual stresses in ductile materials. The system allows the local heating of a small spot and the measurement of the radial in-plane displacement field generated around it. In order to quantify the residual stresses from the measured displacement field, the thermomechancial problem is simulated using the finite element method and a modified hole-drilling model is applied. The performance of the system is evaluated by measuring the stress generated by a preloaded specimen. It is shown that the combined system can measure residual stresses with a typical error of approximately 5 %.