SOLVING VERY LARGE GYROSCOPIC EIGENPROBLEMS BY AUTOMATED MULTI-LEVEL SUBSTRUCTURING

Abstract. Simulating numerically the sound radiation of rolling tires requires the solution of very large and sparse gyroscopic eigenvalue problems. Taking advantage of the automated multi– level substructuring (AMLS) method it can be projected to a much smaller gyroscopic problem, the solution of which however is still quite costly since the eigenmodes are non–real and complex arithmetic is necessary. This paper discusses the numerical solution of the AMLS approximation. Key words. Eigenvalues, AMLS, gyroscopic eigenproblem, substructuring, nonlinear eigen-problem, minmax characterizatio