A Novel Parallel Algorithm for Rotor Dynamics Simulation

Domain decomposition techniques combined with the finite element tearing and interconnecting (FETI) method has become popular for parallel computations in finite element analysis. In the original FETI method, the continuity of the displacement field across the sub-domain boundaries is enforced via the classical Lagrange multiplier technique. In this paper, domain decomposition is used as well, but continuity conditions are imposed via the "localized Lagrange multiplier" technique. In this approach, interface nodes are created and continuity conditions are enforced between the displacements of the boundary nodes and those of the interface nodes. The presence of the interface nodes maximizes the independence of the sub-domains and enables the use of augmented Lagrangian terms that improve the numerical conditioning of the problem. The localized Lagrange multiplier technique is formulated within the finite element framework and the solution procedure of domain-decomposed problem is described in detail. The proposed approach has been implemented in Dymore, a finite element based multibody dynamics code for comprehensive rotorcraft simulation.