Multiphysics-Multiscale Modeling of Materials in Mechanical, Nuclear, and Space Applications

Researcher: Prof. Nasr Ghoniem


Multiphysics-Multiscale Modeling has become an important design tool for the development of new materials and components in severe environments.  Old design methods are being replaced by comprehensive 3D Multiphysics models of intricate geometries using advanced solid modeling tools. These models are coupled with 3D simulations of fluid flow, heat transfer in fluids, heat transfer in solids, and structural mechanics, to give engineers near realistic performance assessments of newly designed engineering components. Fully coupled Multiphysics models are being developed for materials and components operating in severe environmental conditions, such as extreme heat flux and temperatures, extreme radiation fields, extreme crash, impact, and explosion conditions, extreme cold conditions, extreme corrosion and erosion conditions, extremely long operational conditions, and extreme manufacturing conditions by beams and plasmas, etc.  Multiphysics models define the boundary and initial conditions of localized and critical zones in any given design. A top-down multiscale methodology is developed in Professor Ghoniem’s laboratory to “zoom-in” on such critical zones, by modeling the thermomechanical behavior at the continuum length scale, then followed by meso-scale models where the material microstructure is explicitly simulated.  The meso-scale is the most difficult scale to model, because of the many evolutionary and dissipative processes that must be described. The mesoscale includes grains, twin and domain boundaries, precipitates, voids and bubbles, subgrains, dislocation networks, and point defect clusters.  Supporting information for accurate mesoscale models are obtained from atomistic length scale, using a variety of techniques, such as the Molecular Dynamics and Monte Carlo methods.

 UCLA Samueli Mechanical and Aerospace Engineering