The Research On Vibration Faults Diagnosis Technology Of Aviation Auxiliary Power Unit

With the development of China's aviation industry and required by national defense modernization,the development of aviation auxiliary power unit(APU)becomes even more important.More and more APU tests have been and will be performed.Various vibration failures occurred during tests.Since vibration signals can quickly and directly reflect the operating conditions of test parts,by analyzing and processing vibration data,the positions and types of vibration failures can be obtained.In this paper,(1)Types of APU vibration failures are introduced and their causes and features are explained,providing theoretical basis for engineering application.(2)An APU rotor unbalance failure is taken as an example: analyze data using frequency spectrum method,pickup failure characteristic data,in combination with known theories,failure position and cause are found out,and the consistency between theory and analysis result is validated.(3)For more complicated vibration failures,such as spalling caused by LCF,by vibration signal analysis as well as borescope inspection,failure position is figured out;by calculating resonance margin and stress analysis,failure cause is found out,at last failure mechanism is determined.In this paper,the application of vibration failure diagnosis theory in aviation APU is studied.Through the work included in this paper,how to handle when APU has vibration failures is understood,thus providing reference for engineering troubleshooting.