Use of coherent optical techniques in detection and monitoring of stress corrosion cracking

In this work a supplement to corrosion research techniques has been implemented which is based upon coherent optical methods. Specifically, real-time holographic interferometry (HI) and laser speckle photography (LSP) have been explored as a means of characterizing stress corrosion cracking (SCC) initiation and propagation behavior in {alpha}-brass. The advantages of these methods include high sensitivity and the ability to conduct testing in-situ in a non-invasive manner. In addition, measured in-plane displacement data taken from LSP has been used to provide input data for finite element analysis (FEA) programs. Coupling experimental data with numerical methods in this manner has been shown to enhance accuracy over numerical techniques alone while providing full field stress information in the region of interest. Acoustic emission (AE) testing has also been conducted simultaneously to complement and correlate with HI and LSP data.