Parallel Computation of the Nonlinear Forced Response of a Bladed Disk With Friction Contacts Using the FETI Method

The size of the finite element (FE) models used for turbomachinery applications is rapidly growing to consider the whole engine dynamics and the complex dynamic interactions between subassemblies, which are connected by means of removable friction contacts. In this context, the aim of this paper is the introduction of a parallel harmonic balance method (HBM) for the nonlinear forced response analysis of bladed disks with localized contact nonlinearities. The proposed technique is based on the finite element tearing and interconnecting (FETI) method, which requires the decomposition of the FE model into several domains coupled by interface forces that are mathematically modeled using the Lagrange multipliers method. This paper offers a comprehensive overview of the FETI method and its implementation for predicting the nonlinear forced response of a bladed disk assembly with frictional interfaces. It will be shown that the FETI method effectively addresses the limitations and assumptions of state-of-the-art approaches that solve the nonlinear equation of motion using a reduced-order fashion.