FEA and Modal Analysis of a Damped Flywheel with Unbalanced Masses

Abstract

In this paper, the complementary role of Finite Element Analysis (FEA) and Modal Analysis is studied using ANSYS Mechanical APDL. Primarily, two models (2D and 3D) of the flywheel are designed. Then, Finite Element (FE) static-stress analysis of the model was carried out, and it is found that the maximum von Mises stress (403 MPa) on the flywheel is lower than the yield stress (850 MPa) level, i.e. the design of the flywheel is safe. Afterwards, the Modal Analysis of the 3D model is carried out and six mode shapes are obtained at six different natural frequencies. Furthermore, Campbell diagram is plotted and two natural frequencies are identified. Moreover, mode shapes are plotted at the two critical speeds corresponding to their respective damped natural frequencies. The mode shapes are found to be stable, and therefore it can be remarked that the flywheel model is safe to operate within 12000 rpm. Finally, the performance of ANSYS models is determined by comparing analytical solution with the ANSYS results and the ANSYS solutions are accurate and robust.

Keywords

• finite element analysis
• flywheel
• modal analysis
• unbalanced mass