Mechanical Engineering
Graduate Seminar
NOTICE OF SEMINAR PRESENTATION
CANDIDATE: Loris Fontanin
DEGREE SOUGHT: MASc
DATE: 7/31/2026
TIME: 11:30am
PLACE: Room 1101 CEI
TITLE: An ANSYS Mechanical Workflow for Pre-Stressed Modal Analysis of Rotating Structures Using Cyclic Symmetry
Abstract
This seminar presents an ANSYS Mechanical workflow for conducting a pre-stressed modal analysis of a low-speed fan (LSF) disk and blades using cyclic symmetry. The disk and blades are being designed for an LSF rig intended to investigate the aeromechanical response of fan blades subjected to multiple forms of inlet distortions. The design is based on the dynamic behaviour of an existing high-speed fan, with the goal of producing similar blade mode shapes and scaled natural frequencies at a lower operating speed. The challenge is to reproduce the relevant vibration behaviour of the high-speed fan using an LSF disk and blades with different geometry, material properties, loading conditions, and operating speeds. Since these differences directly affect the natural frequencies and mode shapes, the LSF blades must be designed to respond in a similar way without having the same physical characteristics as the high-speed fan blades. The analysis utilizes an inverse structural analysis to determine the blade shape before rotation and aerodynamic loading are applied. These loads are then added to deform the blade and develop internal stress during operation. The resulting operating condition is applied to a modal analysis to determine how the associated stresses affect the blade’s mode shapes and natural frequencies. Since the fan contains 19 identical blade sectors, cyclic symmetry is used to model only one sector rather than the entire assembly, reducing required computational effort while still representing the behaviour of the complete fan. The seminar will discuss the analysis workflow, cyclic-symmetry tools, current results, and validation against the high-speed reference fan.