Intentional Response Reduction by Harmonic Mistuning of Bladed Disks With Aerodynamic Damping
Intentional Response Reduction by Harmonic Mistuning of Bladed Disks With Aerodynamic Damping
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DOI：
10.1115/1.4040898
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发表时间：
2018-06
期刊：
影响因子：
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通讯作者：
S. Willeke;Lukas Schwerdt;L. P. Scheidt;J. Wallaschek
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文献类型：
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作者：
S. Willeke;Lukas Schwerdt;L. P. Scheidt;J. Wallaschek
分析了叶片圆盘的谐波失谐概念，以便有意地将特定模式的强迫响应降低到其调谐幅度水平以下。通过分裂与特定节径图案相关联的模式对，名义上调谐的叶盘的轻阻尼行波模与其反向旋转的补码叠加。因此，形成了一个驻波，其中前一个波列受益于空气动力阻尼力的增加。与以前对随机扰动构型的分析不同，通过调整失谐模式(MT)的谐波含量来故意促进特定模式的稳定化。通过相对于离散叶片的局部振型的重新定向，响应被额外衰减高达7.6%。根据调谐系统的特性，对可实现的幅度减小程度进行了分析预测。此外，还导出了充分分离模式对所需的失谐程度。
A harmonic mistuning concept for bladed disks is analyzed in order to intentionally reduce the forced response of specific modes below their tuned amplitude level. By splitting a mode pair associated with a specific nodal diameter pattern, the lightly damped traveling wave mode of the nominally tuned blisk is superposed with its counter-rotating complement. Consequently, a standing wave is formed in which the former wave train benefits from an increase in aerodynamic damping. Unlike previous analyses of randomly perturbed configurations, the mode-specific stabilization is intentionally promoted through adjusting the harmonic content of the mistuning pattern (MT). Through a reorientation of the localized mode shapes in relation to the discrete blades, the response is additionally attenuated by an amount of up to 7.6%. The achievable level of amplitude reduction is analytically predicted based on the properties of the tuned system. Furthermore, the required degree of mistuning for a sufficient separation of a mode pair is derived.