Effects of blade’s interconnection on the modal characteristics of a shaft-disk-blade system

• Published in: Mechanical systems and signal processing 2021-01, Vol.146, p.106955, Article 106955
• Main Authors: She, Houxin, Li, Chaofeng, Tang, Qiansheng, Wen, Bangchun
• Format: Article
• Language: English
• Subjects: Coupled modes; Coupling; Coupling modal characteristics; Damage; Lacing wire; Mistuning; Shaft-disk-blade; Stiffness; Wire
• ISSN: 0888-3270; 1096-1216
• DOI: 10.1016/j.ymssp.2020.106955

•The tuned/mistuned lacing wire has a significant impact on the coupling modal spectrum of a shaft-disk-blade packet.•The coupling pattern among subcomponents vary versus lacing wire stiffness ratio (KL) and location (XL).•The sensitivity of coupled mode frequencies to lacing wire mistuning depends on a series of factors.•Varying rotational speed will gradually eliminate the effect of lacing wire mistuning on the coupled frequencies. Present work has further developed a packet blade-disk-shaft coupling model based on previous work to interpret the effects of tuned/mistuned lacing wire on the coupled modal properties. In the developed model, the flexible bladed disk system's swing motion inducing by shaft bending is further considered. Corresponding model validation indicates that the improved model is more accurate than our previous model. Present analysis has three parts: in the first part numerical results focus on the effects of varying lacing wire location (XL) and stiffness ratio (KL) on the coupling behavior between subcomponents. As the lacing wire participating in the coupling vibration, the SDB, DB2, and BB mode shift to LSDB, LDB2, and LB mode, while the TDB mode keeps in constant. The frequency values of new coupling modes conspicuously increase, altering the order of occurrence of the dominant modes as well as the patterns of coupling modes. In the second part, a mistuning severity factor has been introduced to represent the lacing wire damage level and its effects on different coupled modes are summarized clearly. Then further analysis points out that the sensitivity of mode frequencies to lacing wire damage depends on a series of factors. The conclusions can provide a reference for the mistuning identification in the shaft-disk-blade packet system. Finally, the effects of rotational speed on the tuned/mistuned shaft-disk-blade packet are compared and depicted in the Campbell diagram.