A comprehensive review of non-destructive techniques for residual stress evaluation: Fundamental principles, validation strategies, and engineering applications

Residual stresses are caused by a variety of processing routes from macro to micro levels. The stresses are also a source of ongoing concern in terms of detection because of their self-equilibrating nature. Residual stresses are known to significantly affect the engineering materials’ strength and mechanical properties. Residual stresses play a significant role in terms of crack initiation around weld beads. It significantly affects the static and fatigue life of structures. Therefore, it is important to accurately determine residual stresses to establish a link between microstructures, mechanical conditions, and failure mechanisms. Since it is not possible to directly measure residual stresses, it is important to indirectly measure them in terms of strain. Therefore, it is an inverse problem to determine residual stresses. The techniques used to determine residual stresses are broadly classified as non-destructive or destructive tests. Even though traditional destructive tests are important, non-destructive tests such as XRD, ND, and ultrasonic tests are gaining prominence because they preserve the integrity of the structures. Advanced techniques such as synchrotron XRD, Raman spectroscopy, and Magnetic Barkhausen Noise are also being used to characterize residual stresses.