Why Is It So Challenging to Measure Residual Stresses ?

BACKGROUND: Residual stresses have a “hidden” character because they exist in a material without the presence of any external loads. They cannot easily be added or subtracted in a quantified manner, as is done when measuring applied stresses, and so are much more challenging to measure. OBJECTIVE: The objective here is to identify and describe the various features that make residual stress measurement methods challenging and to consider the ways that these challenges can be addressed in practice. METHODS: Various of the most common residual stress measurements methods are considered and the challenges associated with them are identified and classified. RESULTS: Five major challenges for residual stress measurements, and the approaches used for their resolution, are identified. CONCLUSIONS: Despite the various challenges that need to be overcome, residual stress measurements can be successfully undertaken in practice. The most significant feature for success is a highly skilled and knowledge practitioner.