Autonomous Damage Recovery of Austenite Steels by Probabilistic Multiscale Mechanokinetic Modeling
Eduard Karpov (University of Illinois-Chicago), Mansoore Ariyan (University of Illinois-Chicago)
From Atomistics to Reality: Spanning Scales in Simulations and Experiments Symposium A
Mon 4:20 - 5:40
CIT 165
We present a probabilistic approach to modeling slow-rate evolutionary processes in solids at the atomic scale coupled with their bulk mechanical behavior at a continuum level. For this purpose, we describe the transient slow-rate atomistic with a Monte-Carlo master equation, and introduce a coupling of the numerical solution for this equation with a finite element solver for a nondeterministic concurrent multiscale framework. Detailed information about atomic trajectories is not preserved within the Monte-Carlo description; however material properties, morphological and geometric parameters are still available as time-dependent system observables. These macroscopic parameters form a time-parameterized family of ensemble average quantities, whose temporal evolution is governed by stochastic processes at the atomic scale. A specific algorithm is proposed to perform a two-way coupling of the Monte-Carlo and finite element solutions to study long-term evolutionary processes of volume diffusion, surface precipitation and creep cavity self-healing [1] in nanocrystalline austenite (Fe fcc) samples. The two-way coupling is achieved through implementation of strain-dependent diffusion rates and dynamical update of the finite element model based on the atomic structure evolution [2]. A strain dependent transition-state theory providing the diffusion rates is discussed as a key element of the present methodology. The effect of macroscopic static loading and cavity geometry on the total healing time is investigated for the material of interest. The approach is widely applicable to the modeling and characterization of advanced functional materials with evolutionary internal structure, surface properties, and synergistic behavior in material systems. References: [1] Shinya, N., Kyono, J., Laha, K., 2006. J. Intell. Mater. Syst. Struct. 17, 1127–1133. [2] Karpov, E.G., Grankin M.V., Liu, M., Ariyan, M. J. Mech. Phys. Solids 60(2), 250-260, 2012.