Detecting Crack Nucleation/Damage Mechanisms In Sea-Based Aviation Environments

TDAs Phase II effort will focus on understanding of microstructural damage evolution during pre-crack nucleation, stress field imposition, development of corrosion susceptibility, and role of environment and the material properties and developing methodologies (electrochemical ) for measuring early response on development of stress field and initiation of corrosion sensitive zones. The planned effort will consist of testing to understand the onset and progression of damage, corrosion modeling from first principles and continuum methods, UniCorr software development and prototype sensor development after assessment of tests and detection techniques. TDAs planned tests will use a set of corroborative NDE techniques to detect crack initiation in corrosive environments. The techniques strongly being considered after Phase I series of tests are ECN, DCPD and LPR. The modeling effort will characterize the corrosion rate from first principles using DFT and KMC techniques as well as continuum models. TDAs vision is to develop predictive capability for environmentally assisted crack initiation in Navy specific material-environment and loading conditions in UniCorr, an easy to use software capable of simulation studies by incorporating critical laboratory tests and service data, and develop prototype sensors for corrosion monitoring and small crack detection by investigating potential combination of different NDE for damage detection.