Interface Balance Laws, Growth Conditions and Explicit Interface Modeling Using Algebraic Level Sets for Multiphase Solids with Inhomogeneous Surface Stress
thesisposted on 16.12.2020, 15:22 by Pavankumar VaitheeswaranPavankumar Vaitheeswaran
Interface balance laws are derived to describe transport across a phase interface. This is used to derive generalized conditions for phase nucleation and growth, valid even for solids with inhomogeneous surface stress.
An explicit interface tracking approach called Enriched Isogeometric Analysis (EIGA) is used to simulate phase evolution. Algebraic level sets are used as a measure of distance and for point projection, both necessary operations in EIGA. Algebraic level sets are observed to often fail for surfaces. Rectification measures are developed to make algebraic level sets more robust and applicable for general surfaces. The proposed methods are demonstrated on electromigration problems. The simulations are validated by modeling electromigration experiments conducted on Cu-TiN line structures.
To model topological changes, common in phase evolution problems, Boolean operations are performed on the algebraic level sets using R-functions. This is demonstrated on electromigration simulations on solids with multiple voids, and on a bubble coalescence problem.