径向简谐激励下航空发动机机匣的振动分析

Vibration analysis of aero-engine casing under radial harmonic excitation

根据航空发动机机匣薄壁结构的几何特征,将机匣简化为一端简支一端固支的圆柱壳结构,建立了系统的动力学方程,并采用多尺度法对动力学方程进行了求解,进而研究了径向简谐激励下机匣动力学方程的零解及非零解的稳定性,并讨论了系统单模态运动发展到复合模态运动以及能量在模态之间的转移过程,最后采用数值方法研究了径向简谐激励下机匣的振动特性.结果表明:随着径向简谐激励的增加,系统表现为周期运动、倍周期运动及混沌运动交替出现.

The casing was simplified using a simply supported end and a fixed supported end cylindrical shell based on geometric characteristics of thin-walled structures of aero-engine casing.The dynamic equations were established and solved by multi-scale method,and the stability of zero solution and non-zero solution of casing dynamic equations under the radial harmonic excitation was studied.Then the transient process of system mode from singlemode motion to composite mode motion and the transfer of energy between the modes were studied;in addition,the vibration characteristic of casing under radial harmonic excitation was also numerically simulated.Results show that periodic motion,periodic doubling motion and chaotic motion appear alternately with the increase of radial harmonic excitation.