Suitability of DIC and ESPI optical methods for monitoring fatigue damage development in X10CrMoVNb9-1 power engineering steel

Abstract

The aim of this research was to compare the effectiveness of two different optical measurement techniques (digital image correlation—DIC and electronic speckle pattern interferometry—ESPI) during fatigue damage development monitoring in X10CrMoVNb9-1 (P91) power engineering steel for pipes. The specimens machined from the as-received pipe were subjected to fatigue loadings and monitored simultaneously using DIC and ESPI techniques. It was found that DIC technique, although characterised by lower resolution, was more effective than ESPI. DIC allows to monitor the fatigue behaviour of steel specimens and accurately indicate the area of potential failure even within the initial stage of fatigue damage development.

Assessment of fatigue life of aluminized, coarse-grained MAR247 alloy supported by full-field ESPI measurements

“…ESPI is an optical technique which is widely used for full-field stress and strain measurements (Kopeć et al, 2021). Although such a technique is not as popular as Digital Image Correlation, it is still recently utilized for fatigue crack monitoring (Farahani et al, 2022), fatigue life analysis of engineering constructions (Chen et al, 2018) or residual stress determination (Gao et al, 2021).…”

Bulletin of the Polish Academy of Sciences: Technical Sciences

“…However, such tests provide only limited knowledge on material behavior since the data from the test is derived from strain gauge only. Such limitations could be solved by using full-field optical methods, namely electronic speckle pattern interferometry (ESPI) and digital image correlation (DIC) [8]. DIC was found to be an effective tool to ensure the reliability of pressure vessels during service.…”

“…DIC was found to be an effective tool to ensure the reliability of pressure vessels during service. Although DIC could be used to monitor full-scale components, it has a significantly lower resolution than ESPI [8]. ESPI is the optical technique in which the stress/strain distribution maps can be determined during fatigue testing for a relatively large area of the specimen.…”

“…ESPI technique is based on holographic interferometry in which the laser beam is distracted from the optically rough surface. Because it is capable to detect cracks in actual and residual stress fields [9], this technique has been widely used to monitor deformation on metallic specimens including steel [8] and aluminum [9] as well as AA2124/SiC metal matrix composites [10] or nickel based superalloys [11]. Hence, it has been found to be a promising tool in stress distribution maps determination for P91 steel specimens tested under different states and in their elastic range.…”