摘要
Failures due to high-cycle fatigue have led to a high cost in aerospace engineering over the past few decades.In this paper,the experimental results of the fatigue behavior of compressor blade specimen subjected to resonance and the effects of a damping hard coating on relieving the fatigue progress are presented.The crack initiation and propagation processes were observed under resonance of the first bending mode by using the resonant frequencies as the indicator.Significant nonlinear features were observed in the spectrum of the blade with a fatigue crack.The finite element model considering the breathing crack was established with nonlinear contact based on the crack localization and size,which was obtained by ultrasonic phased array technology.The simulation results of the vibration behavior of the cracked blade were obtained and consistent with the experimental results.A NiCrAlY coating was deposited on the blade,and increases in the fatigue life were observed under the same condition.The results of this paper can help to better understand the fatigue of a compressor blade subjected to resonance and provide a preference for the application of a damping hard coating on compressor blades.
高周疲劳导致的失效在过去几十年内对航空工程领域造成了巨大损失。本文给出了压气机叶片试验件在共振态下的疲劳试验结果,以及阻尼硬涂层对延缓振动疲劳的影响。以共振频率的变化为指标观测了一阶弯曲共振下的叶片试验件裂纹萌生和扩展过程;在出现疲劳裂纹叶片的振动时域图和频谱图中观察到了明显的非线性特征。利用超声相控阵技术辨识了疲劳裂纹的位置和尺寸,进而使用非线性接触的方法建立了考虑呼吸效应的裂纹叶片有限元模型,得到的裂纹叶片振动特性仿真结果与试验结果一致。在相同的试验条件下,通过在叶片试验件表面喷涂NiCrAlY涂层,研究发现试验件的阻尼性能明显提高、振动疲劳寿命延长。本文的研究结果有助于更好地理解压气机叶片的振动疲劳特性,为阻尼硬涂层在压气机叶片上的应用提供参考。
基金
Project(DUT20RC(3)014)supported by the Fundamental Research Funds for the Central Universities,China,Project(VCAME201801)supported by Key Laboratory of Vibration and Control of Aero-Propulsion System(Ministry of Education),China
Project(11472068)supported by the National Natural Science Foundation of China。
