Longitudinal critically refracted (LCR) ultrasonic wave for residual stress measurement

The article deals with the state-of-the-art in the field of Longitudinal critically refracted (LCR) ultrasonic wave, for non-destructive material evaluation. It checks its capability for residual stress identification, and reviews positives and negatives related to its use. Obtained information within the article, are used for the understanding of essence of method and for the evaluation of its use in the engineering practice. The article can be the source of information about the LCR wave measurement technology, which is the part of the complex ultrasonic testing method. For the frequency of using this technology for surface residual stress measurement, it is appropriate to have this information in one whole, which are gathered of the outputs of researches by various authors. The paper is divided in few sections and sub-sections. In the first section, information about LCR wave technique and factors correlated with this method, are provided. The next section writes about residual stresses and the importance of their identification. Next, the principal of residual stresses measurement and basic structure of measurement device, is described. A significant part of study, describes the state so far of theoretical and practical researches within the use of this method, in the technological practice of residual stress identification in surface layers of engineering components. In the conclusion, obtained knowledges are summarised and evaluated. Related positive and negative aspects are included, with a verifying the need of future researches.

Residual Stress Measurement Tools and Methods: Industrial View of Current Gaps and Opportunities

Residual stress measurement is necessary in several aspects of product development and sustainment: structural analysis of components, process quality validation, model development and validation, and understanding the root-cause of failure events. Especially in the aerospace industry, accurate residual stress assessment is critical due to the higher safety standards. However, limited tools and methods are available for different components and applications. Goal of this presentation is to review pros and cons of the various methods, discuss the technical challenges in stress determination, and introduce potential solutions to overcome the current limits.