A fast contraction mapping for solving multibody systems

Argonne National Laboratories, 9700 South Cass Avenue, Argonne, IL 60439, USA.The simulation of complex multibody systems with contacts and friction requires a fast and robust solver for complementarityproblems. This work presents an efficient method which can so lve large cone-complementarity problems by means of a fixedpoint iteration. Our method performs like a contractive mapping, providing a monotonic approximation to the exact solution.The algorithm features high computational performance even if thousands of unilateral constraints are added to the system.Also, this scheme fits well in a real-time simulation context because it can be terminated prematurely. As a benchmark fortesting the method in challenging situations, we propose the simulation of the granular flow in a fourth-generation bebble-bednuclear reactor, including 150’000 rigid bodies and more than a million of constraint multipliers.