STATIC STRUCTURAL AND MODAL ANALYSIS OF A MULTISTAGE AXIAL COMPRESSOR USING MULTISTAGE CYCLIC SYMMETRY

Abstract

Multistage cyclic symmetry analysis provides an efficient framework for evaluating complex
turbomachinery assemblies composed of multiple cyclically symmetric subsystems with different
sector counts. This study presents the static structural, modal, and prestressed modal analysis of a
four-stage axial compressor model consisting of three blade rows and a supporting rim.
Each stage is modeled as an independent cyclic subsystem and connected using multistage
interstage coupling. The structure is subjected to rotational speed, stage-wise pressure loading, and
thermal gradients to simulate realistic operating conditions.
Static results show stress concentration at blade roots and interstage interfaces, while modal
analysis reveals harmonic-index-dependent vibration behavior. Prestressed modal analysis
demonstrates centrifugal stiffening effects and frequency shifts under operational loads.