中文摘要：

针对涡轴发动机动力涡轮转子起动过程中的振动信号，采用奇异值分解方法实现非平稳振动信号的去噪和奇异值重构，从中提取起动信号的振动特性。发现某涡轴发动机凸台1和凸台2的振动主频为154Hz，为涡轴发动机2阶临界转速的2/3倍频，凸台3的振动主频为160Hz。这些振动特征可为发动机振动排故和动平衡提供参考信息。

英文摘要：

The vibration signal in starting process of the power turbine rotor of a turboshaft engine is analyzed.The singular value decomposition method is applied to realize the non-stationary vibration signal denoising and singular value reconstruction.The vibration characteristics of the starting vibration signal can be obtained by the singular value reconstruction.It is found that the main frequencies of the turboshaft engine for convex platforms1and2are all154Hz,which is the2/3octave frequency of the second order critical speed of the power turbine rotor.The main frequency of the engine for convex platform3is160Hz.These vibration characteristics can provide reference information for engine vibration troubleshooting and dynamic balancing.