Rotor blade displacement field measuring method based on blade end timing and system thereof

Abstract

The invention discloses a rotor blade displacement filed measuring method based on a blade end timing and a system thereof. The method comprises the following steps: establishing a three-dimensional finite element model of a rotor blade to be measured, and extracting a modal parameter of the three-dimensional finite element model; determining a blade end timing sensor number and a peripheral mounting position; establishing a mapping relationship between single-point displacement and comprehensive-field displacement of the blade; and acquiring the rotor blade end single-point displacement basedon the blade end timing sensors, wherein the single-point displacement is acquired at any position and in any direction based on the mapping relationship. Through adoption of the method provided by the invention, the reconstruction of the overall rotor blade displacement field of the blade can be realized by using the blade end finite measuring points, so that measurement of all node displacements on the surface and inside of the rotor blade can be realized under the multi-modular vibration. The calculation process is simple, and online measurement can be performed easily.

Description

technical field [0001] The invention belongs to the technical field of non-contact vibration testing of aeroengine rotor blades, in particular to a method and system for measuring rotor blade displacement field based on blade end timing. Background technique [0002] The integrity of the blade directly affects the safe operation of the overall structure of the aeroengine. Affected by factors such as harsh working environment and strong alternating loads, it is very easy to generate vibration fatigue cracks during service and cause serious accidents. High cycle fatigue caused by excessive blade vibration is the main failure mode of aeroengine blades. The high cycle fatigue of the rotor blade is mainly caused by the dynamic stress caused by various aerodynamic loads and mechanical loads, and a large number of cycles can accumulate fatigue cracks in a short period of time, especially when the blade resonates, the dynamic stress can easily lead to the fatigue failure of the blad...

AI Technical Summary

Problems solved by technology

For a long time, aeroengine blades have achieved dynamic strain measurement by pasting strain gauges on the surface of rotor blades, which can only measure dynamic strain at limited positions on limited blades, and their reliability and continuous working time are low, especially in high temperature environments. A large number of strain gauges are arranged on the blade, often only a few strain gauges can obtain effective information, and the survival rate is extremely low

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