整体叶盘结构模态特性分析及应力分布规律

为了研究整体叶盘结构的模态特性及应力分布规律，基于有限元分析方法建立了整体叶盘结构有限元仿真模型，对自由状态及离心力载荷下的整体叶盘进行模态及振动特性分析；并探究实心与空心整体叶盘的应力分布差异及不同叶片间隙的整体叶盘应力分布规律。为了验证仿真结果的准确性，基于多点激励单点响应方法开展了整体叶盘结构模型的模态试验，并在多功能转子实验台上开展不同转速下应力测试试验。结果表明，该结构模态频率的仿真结果与试验测试结果误差在4%以内，验证了所建立的有限元仿真模型的正确性；应力测试试验验证了其不同转速下的应力分布规律；离心力载荷对整体叶盘二节径振动下固有频率影响最为显著；空心叶盘较实心叶盘应力集中现象更为突出，且叶片根部应力值会随着叶片间隙的增大而有明显提高。

Modal Analysis and Stress Distribution of the Blisk Structure

In order to study the modal characteristics and stress distribution of blisk structure, the finite element simulation model of blisk structure was established based on the finite element analysis method, and the modal and vibration characteristics of blisk under free state and centrifugal force load were analyzed. The difference of stress distribution between solid and hollow blisk and the law of stress distribution of blisk with different blade clearance were explored. In order to verify the accuracy of the simulation results, the modal test of the blisk structure model was carried out based on the multi-point excitation single-point response method, and the stress test at different speeds was carried out based on the multifunctional rotor test bench. The results show that the error between the simulation results and the experimental results is less than 4%, which verifies the correctness of the finite element simulation model. The stress distribution law under different rotating speeds is verified by stress test. The centrifugal load has the most significant effect on the natural frequency of the second nodal diameter(ND) vibration of the blisk. The stress concentration of hollow blisk is more prominent than that of solid blisk, and the stress value of blade root will increase significantly with the increase of blade clearance.