Amplitude control based aviation engine blade vibration fatigue testing method

Abstract

The invention discloses an amplitude control based aviation engine blade vibration fatigue testing method. A non-contact laser amplitude monitoring system is adopted. The amplitude of the end parts ofblades of an engine is monitored in real time. The amplitude of the end parts of the blades of the engine is taken as feedback signals. If that the dynamic amplitude deviates from a test preset valueis detected, a measurement and control system sends a modification command in real time. The amplitude constancy of the end parts of the blades of the engine is maintained through adjusting the magnitude of excitation drive current or adjusting excitation frequency. The amplitude control precision is superior to 1%. Therefore, a reliable blade vibration fatigue testing result can be acquired.

Description

technical field [0001] The invention belongs to the technical field of vibration fatigue tests, in particular to an aeroengine blade vibration fatigue test method based on amplitude control. Background technique [0002] The fatigue failure caused by the vibration of the blade is the main failure mode of the compressor blade under the action of the periodic airflow excitation force of the aero-engine compressor. The failure of blades will directly affect the stability of the engine, and even cause catastrophic aviation accidents. Therefore, it is of great significance to study the vibration fatigue life of engine blades to ensure the normal and stable operation of the engine. [0003] In the traditional blade vibration fatigue test, the blade is usually rigidly fixed on the surface of the electromagnetic vibrating table, and the excitation frequency is selected near the first-order resonance frequency of the blade by using the principle of resonance amplification, and the b...

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Problems solved by technology

Since the vibrating table uses the acceleration control mode, in the vibration fatigue process, in order to keep the acceleration constant, the driving voltage of the vibrating table will be slightly adjusted, and the blades of the aero-engine are made of low-damping alloy material, which presents a narrow and high amplitude when resonating. The frequency response characteristics, under the action of resonance amplification, cause huge fluctuations in the amplitude of the blade, making the amplitude (strain) fluctuation range of the blade exceed 10% or even higher of the predetermined amplitude, and the fluctuation is too large to maintain stability, thereby reducing the blade Reliability of Vibration Fatigue Test Results

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