根部连接刚度对旋转叶片振动特性的影响

以一个扭型、变截面旋转叶片为研究对象，基于ANSYS有限元软件，采用变厚度的壳单元建立了叶片的有限元模型，并与实体单元进行对比；通过二者的固有频率和振型来验证本建模方法的准确性.随后分析了在离心刚化、旋转软化效应和科氏力共同作用下，径向连接刚度对叶片动频特性的影响，以及在离心力和气动力共同作用下径向连接刚度对叶片幅频响应的影响.研究结果表明，较小的径向刚度会产生刚体振型，且响应主要集中在低频段；中等径向刚度会产生一些耦合振型，响应集中在高频段；大的径向刚度接近固支情况，响应幅值较前二者小.

Influence of Root Connecting Stiffness on Vibration Responses of Rotating Blades

Taking a rotating twisted blade with variable cross-section as a research object, a finite element model of the blade was established using shell elements with variable thickness in the ANSYS software. The model was verified by comparing the natural frequencies and their modal shapes of the shell elements with those of the solid elements. The influence of the radial blade root connecting stiffness on the blade dynamic frequency characteristics was analyzed under the joint action of centrifugal force, spin softening and the Coriolis force, as well as on its amplitude-frequency response under the joint action of centrifugal force and aerodynamic force. The results show that, when the radial connecting stiffness is low, the rigid body vibration modes appear within low frequencies, the modest radial connecting stiffness contributes the coupling vibration modes which occur mainly at high frequencies, and the vibration mode under the large radial connecting stiffness condition is similar to that of fixed support and the response amplitude is smaller than that of the first two.