Digital Image Correlation and the Contributions of Stress-Strain Measurements towards Failure Analysis

Failure mechanisms contributed by stress or material fatigue have been witnessed in several industrial as well as at R&D applications in various forms. Metallurgical studies for failure analysis have ensured the contributions of residual stress in several cases. The most important and common consideration in all these cases has been the material. Definitely, there may be other contributing factors also like sudden load, operating temperature, lack of lubrication etc. The most vital aspect of all the scientific observations remains to search the accurate cause with parameters & the subsequent measures for remedy. Here, lies a very close & important relation between Condition Monitoring activities & Failure analysis studies. While mainly metallurgical engineering which includes in-depth study of microstructure, grain boundaries etc. dominates the field of failure analysis, on the other hand a combination of various streams starting from instrumentation to mechanical, which again includes lubric ant analysis, vibration based signature analysis, sophisticated systems like digital image correlation constitute the domain of Condition Monitoring. But it must be acknowledged that failure analysis studies pave the way for Condition Monitoring activities, since it indicates the parameters that are needed to be monitored & controlled. Hence, failure analysis strengthens the condition monitoring initiatives. However, this paper mainly highlights upon the various causes and features of material fatigue or fatigue failure, their occurrence at industrial sectors and the subsequent experimental procedures for stress-strain measurement in R&D.