Modelling and vibration evaluations of rotational mistuning-connecting disk-drum coupling structures with partial hard-coating damping treatment

Mistuning connections between drums and disks are very common in engineering. How-ever, this point has not been mentioned in previous studies. This work develops discontin-uous arc connections with different connecting stiffness to simulate actual mistuning con-nections by modifying the traditional spring method with continuous distributions. The ad-mission functions are represented by good-convergence orthogonal polynomials. Through considering the rotation-generated gyroscopic and centrifugal effects and utilizing Kirch-hoff's plate theory and Sanders' shell theory, the dynamic model of rotational mistuning-connecting disk-drum coupling structures with partial hard-coating damping treatment (PHDT) is derived through Lagrange equations and verified by utilizing FEA and exist-ing literature, in which the partial-coating model is more suitable for practical vibration suppression than the existing whole coating model. Moreover, further mistuned vibration evaluations show that the mistuning connections induce the change of mode order, fre-quency division, and vibration localization. The veering phenomenon caused by mistuning is also revealed, and the modal coupling and dominant mode exchange during veering are explained by the change of mode shape and MAC. Furthermore, the mistuning will also seriously affect the key information (critical speeds, instability positions, and veering posi-tions) in Campbell diagrams. The present model provides key technical references for the vibration prediction, connection fault diagnosis, and coating parameter optimization of ro-tational disk-drum coupling structures with PHDT.(c) 2022 Elsevier Inc. All rights reserved.

Automated summary

This study develops discontinuous arc connections with different connecting stiffness to simulate actual mistuning connections. The dynamic model of rotational mistuning-connecting disk-drum coupling structures is derived and verified. The mistuning connections induce changes in mode order, frequency division, and vibration localization. Mistuning also affects the key information in Campbell diagrams.