Aero-engine blades may crack under harsh operating environments. This reduces the reliability of the aero-engine and causes catastrophic accidents. Although dynamic modeling and vibration characteristics of simplified blades with cracks have been analyzed extensively, there are few studies on the actual compressor blade with varying sections and twisted shapes. Based on Timoshenko beam theory, a new modeling approach for the compressor blade is proposed. Next, according to the strain energy release rate and Castingliano theory, the dynamic model of cracked compressor blades is established considering the stiffness nonlinearity induced by the breathing crack. The modeling approach is validated by the measured natural frequencies of an intact blade. Then, the dynamic model of the cracked blade is verified by comparing the modal characteristics and vibration characteristics using ANSYS software. Finally, some results show that the natural frequencies , , and increase as the pre-twisted angle and stagger angle increase. Due to the breathing effect, some integer frequencies appear in the spectrum including 0 and 2, and the variations in the amplitude of frequencies 0 and 2 are monotonic under different aerodynamic amplitudes. The research can provide some help for the modeling of the actual blade and fault diagnosis of cracked blades.

中文翻译：

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基于梁单元的含裂纹旋转压气机叶片动力学建模与验证


航空发动机叶片在恶劣的工作环境下可能会破裂。这降低了航空发动机的可靠性并导致灾难性事故。尽管人们对含裂纹简化叶片的动力学建模和振动特性进行了广泛的分析，但对实际的变截面和扭曲形状压气机叶片的研究却很少。基于Timoshenko梁理论，提出了一种新的压气机叶片建模方法。接下来，根据应变能释放率和Castingliano理论，考虑呼吸裂纹引起的刚度非线性，建立了裂纹压气机叶片的动力学模型。该建模方法通过测量完整叶片的固有频率进行了验证。然后，利用ANSYS软件比较模态特性和振动特性，验证了裂纹叶片的动力学模型。最后，一些结果表明，固有频率 、 、 和 随着预扭角和交错角的增加而增加。由于呼吸效应，频谱中出现了包括0和2在内的一些整数频率，并且频率0和2的幅度在不同气动幅度下的变化是单调的。该研究可为实际叶片建模和裂纹叶片故障诊断提供一定帮助。