某涡扇发动机涡轮叶片动测应变模态频移现象分析  

Analysis of resonant frequency shift phenomenon raised from dynamic strain measurement data of turbine blade in a turbofan engine

作　　者：黄行蓉 孙赫 吴坚 范兴超 沈庆阳 张大义[5,6] HUANG Xingrong;SUN He;WU Jian;FAN Xingchao;SHEN Qingyang;ZHANG Dayi(Sino-French Engineering School,Beihang University,Beijing 100191,China;Hangzhou Innovation Institute,Beihang University,Hangzhou 310023,China;Research Institute of Aero-Engine,Beihang University,Beijing 102206,China;Sichuan Gas Turbine Establishment,Aero Engine Corporation of China,Chengdu 610500,China;School of Energy and Power Engineering,Beihang University,Beijing 102206,China;Beijing Key Laboratory of Aero-Engine Structure and Strength,Beihang University,Beijing 102206,China)

机构地区：[1]北京航空航天大学中法工程师学院,北京100191 [2]北京航空航天大学杭州创新研究院,杭州310023 [3]北京航空航天大学航空发动机研究院,北京102206 [4]中国航发四川燃气涡轮研究院,成都610500 [5]北京航空航天大学能源与动力工程学院,北京102206 [6]北京航空航天大学航空发动机结构强度北京市重点实验室,北京102206

出　　处：《航空动力学报》2022年第11期2388-2397,共10页Journal of Aerospace Power

基　　金：国家自然基金(52105083,52175071);国家科技重大专项(J2019-Ⅳ-0023-0091);先进航空动力创新工作站(HKCX2020-02-016)。

摘　　要：某高推质比涡扇发动机高压涡轮叶片采用缘板干摩擦阻尼设计,以降低叶片振动应力;在核心机地面台架试车中,应变测试数据的频域特征出现漂移现象,振动能量在频域内呈现出窄带随机的特征。围绕该现象,基于试验数据建立了考虑缘板阻尼块影响的单个叶片等效模型,基于时域积分算法和非线性模态理论计算了不同转速下系统的响应特征、摩擦力特征、共振频率特征和摩擦阻尼特征。研究结果表明:转速波动会影响系统的振动响应频域分布特征和共振频率分布范围:在11 713 r/min转速状态,9倍频会激起1 756~1 952 Hz频率带的共振;在13 500 r/min转速状态,8倍频会激起1 800 Hz频率附近的共振;在13 687 r/min转速状态,8倍频会激起1 596~1 824 Hz频率带的共振;在稳定转速条件下,干摩擦力在最大和最小值之间反复跳变,起到摩擦阻尼效用的同时,带来系统附加刚度的不稳定变化;非线性模态计算结果表明叶片模态频率随振动响应幅值的变化而变化,叶片刚度变化或摩擦力幅值增大均可使叶片模态频率区间变大。A high-pressure turbine blade of a high thrust-to-weight ratio turbofan adopted edge plate damper design to reduce the vibration stress of the blade. During the core machine ground bench test, the frequency-domain characteristics of the strain test data showed drift phenomenon, and the vibration energy presented random feature in a narrow frequency band. The phenomenon was discussed and analyzed at first. Then the equivalent model of a single blade considering the influence of the edge plate damper was established according to test data. Based on the time integration method and the nonlinear modal theory,the response characteristics, friction characteristics, resonant frequency characteristics and friction damping characteristics of the system were calculated under different rotation speeds. The simulation results showed that the rotation speed fluctuation affected the frequency domain distribution characteristics of the vibration response and the resonant frequency range distribution of the system: at 11 713 r/min, the nonuple excitation order induced the resonance frequency band of 1 756—1 952 Hz, at 13 500 r/min, the octuple excitation order induced the resonance frequency around 1 800 Hz, and at 13 687 r/min, the octuple excitation order induced the resonance frequency band of 1 596—1 824 Hz. Under stable rotational speed, the dry friction force jumped alternatively between the maximum and minimum values, which reflected a friction damping effect and brought about unstable changes in the additional stiffness of the system. The nonlinear modal theory results showed that the modal frequency of the damped blade changed with the vibration response amplitude. The decrease of the blade stiffness or the increase of the friction force amplitude can enlarge the modal frequency range.

关 键 词：叶片动测数据 缘板阻尼 非线性模态 模态频移 窄带随机特征 

分 类 号：V214.1[航空宇航科学与技术—航空宇航推进理论与工程]