The Impact of Mistuning and Material Damping on Bladed Disks of Similar Geometries

Abstract

As advances in turbomachinery manufacturing have continued to improve, integrally bladed rotors or blisks have become more prevalent due to the aerodynamic improvements that can be derived from those designs. Despite increases in efficiency, these blisks are prone to significantly higher vibrations due to the removal of friction damping that naturally occurs at the interfaces between each blade and the disk. Mistuning is characterized by a lack of symmetry due to the inevitable imperfections and non-homogeneity that arise across blades from manufacturing inaccuracies and use. Here we report on the frequency response functions of multiple tuned and mistuned academic blisks. The various blisks also exhibit different damping levels based on the material and thickness. These blisks were tested experimentally to determine how the different damping would affect the system response.