UnioGrow & UnioCorr Life Prediction Models
May 29-June 3, 2016
In this brief, UniGrow-UniCorr framework for fatigue crack initiation, growth, and corrosion are discussed along with perspectives on modeling and sensor development for detecting on-set of corrosion damage. The UniGrow crack growth program is first described with brief discussion of its formulation, implementation, and validation results. Various features that are currently present in UniGrow software and planned extensions are also discussed. The current status and development plans for UniCorr to address stress-free and stress-assisted environment assisted cracking are then described.
Salient aspects of corrosion modeling are briefly described along with a description of a continuum damage mechanics model to study pit-to-crack transition life in aluminum alloys. Current development efforts that are underway to advance model prediction based on multi-physics study of corrosion fatigue damage mechanism by taking into account the microstructural features are described. In this context, coupled modeling of micro-plasticity and micro galvanic process is discussed to address the synergistic effect between stress and corrosion. The effects of intermetallic particles on pit initiation and growth mechanisms as well as stress effect on corrosion kinetics are described.
Requirements and challenges in appropriate sensor development especially for those intended as leave-in-place devices and for detecting on-set of corrosion crack initiation are outlined.
Nagaraja Iyyer, "UnioGrow & UnioCorr Life Prediction Models" in "International Workshop on the Environmental Damage in Structural Materials Under Static Load/Cyclic Loads at Ambient Temperatures", A.K. Vasudevan, Office of Naval Research (retired), USA Ronald Latanision, Exponent, Inc., USA Henry Holroyd, Luxfer, Inc. (retired) Neville Moody, Sandia National Laboratories, USA Eds, ECI Symposium Series, (2016). http://dc.engconfintl.org/edsm/28