A wave-based model reduction approach for dynamic analysis of bladed disks
Résumé
In this paper, a wave finite element (WFE) approach is proposed for the modeling of bladed disks subjected to an engine order excitation. Such structures are cyclic symmetric with identical substructures in the circumferential direction. The proposed approach involves (i) expressing the displacements and forces at the interfaces between the substructures in terms of wave modes, (ii) expressing the external forces in terms ofwavemodes, and (iii) solving a local/substructure equation for expressing wave amplitudes. Besides, a model reduction strategy is proposed to improve the efficiency of the WFE method for bladed disks containing substructures with many internal and interface DOFs, where the key idea is to express the displacement vectors at the substructure interfaces with a small number of boundary modes. With this strategy, the wave modes can be efficiently computed by solving a small eigenproblem. Also in this paper, the proposed approach is extended to the analysis of bladed disks with a few perturbed substructures (mistuning). To control the accuracy of the WFE approach, an error indicator that considers a force balance equation at the substructure interfaces is proposed. Numerical simulations are carried out on a 3D industrial bladed disk.