THE INFLUENCE OF MISTUNING AND CORIOLIS EFFECTS ON THE MODAL PARAMETERS OF BLADED DISCS: AN EXPERIMENTAL STUDY

摘要

A very detailed experimental analysis at several different rotational speeds was conducted on a simplified blisk to gain in-depth understanding of how the Coriolis effects and their interaction with mistuning evolve with speed to provide a better understanding for future designs. Two different nodal diameter families, characterised by different levels of mistuning, were investigated in greater detail. The blisk dynamics were found to depend both on mistuning levels and speed. Split Campbell diagrams were observed, together with the appearance of Coriolis-induced forward and backward travelling wave modes in the blisk. Three speed ranges characterised by different behaviours were identified at a high level of detail, with a gradual transition from mistuning-dominated behaviour at low speed to Coriolis-dominated features at higher speeds. The evolution of the,mode shapes with speed, and the differences between low- and high-mistuning modes were particularly examined. The evolution of the mode shapes with speed, and the differences between low-and high-mistuning modes were particularly examined. An accurate comparison was conducted between the measurement data and finite element results, and confirmed the reliability of the new approach.