初期設計に適用できる簡易的なインテンショナルミスチューンの手法と効果の確認

抄録

In blade vibration of Blade Integrated Disk, unavoidable random mistuning due to manufacturing and wearing in operation, amplifies the blade vibratory response, leads to High Cycle Fatigue severity. It is desirable to robustly suppress this Amplification Factor (AF) at all resonance points in the operating range. Referring Martel⁽⁴⁾, Fourier components, forming mistune distribution, make couple between two Traveling Wave (TW) modes, when these eigenvalues close to excited frequency and differences between these TW numbers are equal to the Fourier index, and leads to AF>1. Especially, TW modes of resonating Nodal Diameter (ND) and its conjugate (-ND), tend to pulled into coupled, because of close eigenvalues to excitation. So, we expected that excluding Fourier component |2ND| from mistuned distributions will contribute for keeping AF ≈ 1, and have confirmed AF suppression effect about such a distribution created by arranging two types of blades with different eigenvalues using a 1D simulation tool.