Preconditioning strategies for linear systems arising in tire design

In this paper, we consider linear systems arising in static tire equilibrium computation. The heterogeneous material properties, nonlinear constraints, and a 3D nite element formulation make the linear systems arising in tire design diicult to solve by iterative methods. An analysis of matrix characteristics attempts to explain this negative eeect. This paper focuses on two preconditioning techniques | a variation of an incomplete LU factorization with threshold and a multilevel recursive solver | that are able to improve the convergence of a suitable iterative accelerator. In particular, we compare these techniques and assess their applicability when the linear system diiculty varies for the same class of problems. The eeect of altering the values of parameters such as number of ll-in elements, block size, and number of levels is considered.