Mixed finite element approach for Cahn–Hilliard-type diffusion coupled with elasticity
摘要
Microstructure evolution of materials over space and time is typically studied through the solution of Cahn–Hilliard (CH)-type diffusion and deformation equations. In this work, a numerical framework implemented in commercial software, Abaqus as user element (UEL) and user material (UMAT), is presented to model the complex material behavior during microstructure evolution. This is done by formulating the system’s free energy that comprises chemical, interfacial, and elastic strain energy and phase separation dynamics. The elastic strain energy is expressed as a function of species concentration based on Khachaturyan’s elasticity theory. The species evolution is governed by the fourth-order CH equation and is subsequently transformed into two second-order equations amenable to traditional