Vibratory characteristic analysis of integral mistuned bladed disk assemblies for aeroengine

Abstract

An improved hybrid interface substructural component modal synthesis method (IHISCMSM) is proposed to increase the computational efficiency of mistuned bladed disk assemblies (BDA) under the condition of meeting the computational accuracy for a large amount of calculation via the classical hybrid interface substructural component modal synthesis method (CHISCMSM). The parametric models of the blades and the disk are built to investigate each substructural finite element model. They are synthesized by the double coordinating conditions of the displacement and the force to obtain natural frequency and vibratory output response which will ensure the computational accuracy. Compared with the high fidelity integral structure finite element method (HFISFEM), the computational time is shortened by 23.86–31.56% and the modal deviation is 0.002–0.157% via IHISCMSM. It is faster by 4.46–10.57% than the CHISCMSM. Meanwhile, the factors which impact the frequency are researched by IHISCMSM, including rotational speed, gas temperature, and geometry size. It is shown that the rotational speed makes the frequency increased, the gas temperature makes it declined, the rotational speed has greater influence on the low-order modal, but the temperature has greater influence on the high-order modal. The frequency of the BDA does not change much when the rotational speed and temperature are both considered. However, the geometric dimensioning almost has no influence on the frequency. The vibratory output response is enlarged with the mistuned level increasing and multiple peaks are observed. The reason is that the combined action of the mistuning and the resonance. When the mistuned level is 0–3%, the incremental saltation of the output response is obvious. When the mistuned level is continuing increasing, the localization phenomenon of the output response does not much different from the mistuned level 3%. The above research lays a solid foundation for the further study on the probabilistic analysis of the mistuned BDA.