A Method for Obtaining Vibration Stress of Engine Rotor Blades

Abstract

The invention provides a static testing method for obtaining the vibration stress of a rotor vane of an engine under noise excitation. The method comprises the following steps: simulating the noise excitation by using a travelling wave sound field; simulating a vane root force boundary caused by a rotational speed by a vane root jacking force method; obtaining the largest mean square root principal stress at a part with the largest vibration stress of the rotor vane by a dynamic strain testing means. By the method, the vibration stress under the noise excitation and each fixed physical speed of the rotor vane can be tested, the direction of the noise excitation of the rotor vane can be conveniently considered, the experimentation cost is lower, multiple problems, for example, a high-power motor is needed for driving, and a costly annular electric brush is needed to lead out a strain signal which are caused by the fact that a noise excitation test is performed under the situation that the rotor vane rotates are solved, and the problem that the sound field is difficult to control under the situation that the rotor vane rotates is also solved.

Description

technical field [0001] The invention relates to the field of aero-engine structural strength, in particular to a static test method for obtaining vibration stress of engine rotor blades. Background technique [0002] Engine rotor blades are one of the key components of aero-engines, and their working conditions are harsh. The rotor blades not only bear large centrifugal loads and high blade tip speeds when rotating at high speeds, but also are in complex fields coupled with flow fields, temperature fields, and sound fields. Under the working environment, its static stress and dynamic stress levels are relatively high. Vibration stress is one of the main stress states of rotor blades when they are working, and the vibration stress of rotor blades mainly comes from airflow disturbance, noise excitation or vibration transmitted by blade discs. For example, in the document Tao Chunhu et al., Failure and Prevention of Aeroengine Rotating Parts, National Defense Industry Press, I...

AI Technical Summary

Problems solved by technology

[0003] It is very important to test the vibration stress of the engine rotor blades under noise excitation, and the test cost of the vibration stress caused by the noise excitation is high when the engine is turned on. It needs a high-power motor drive and expensive ring brushes to lead to the strain signal. At the same time, the test Difficult to control the sound field in the case of rotation

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