Interactive multipysics and complex mechanical system
How can the real world, with all its complexity and dynamics on different time and length scales, fit in a computer program? Well, it cannot, something has to go. The question is what properties of the real world need to be captured in order to make a virtual replica realistic. And then there is the question of how to make the computations fly, e.g., to make applications run at interactive rate or exploit the full potential of a supercomputer.
The research addresses multidomain modeling, numerical methods, and software for fast multibody system dynamics with nonsmooth phenomena. Variational time-stepping of large-scale rigid multibody systems with frictional and impacting contacts, mesh free solid and fluids, and mechatronic systems (vehicles, robots) are of particular interest, as well as sparse direct, iterative and parallel solvers of the resulting linear complementarity problems. The approach allows for fast and stable simulation with large time-steps. One domain of applications is real-time visual interactive simulators for training, education, design & prototyping and computer games. Another domain is the research and development of complex and large-scale systems with simulation as a tool to for understanding the dynamics and to find the best approaches for optimization and control.
The results include numerical solution techniques for strongly coupled multibody systems with closed loops, e.g. machine tracks or cloth. The multiphysics framework have been extended to include electronics and hydraulics as multibody constraints and constraint regularization and stabilization terms have been derived from conventional viscoelastic constitutive laws for contacts and for deformable solids. The latter have been implemented and used for large-scale simulation of granular materials (>1M bodies), compared to the conventional discrete element method (DEM) and applied for the outlet design optimization in iron pellets production. The possibilities of embedding interactive physics in the web browser have been explored.