Modal analyzing method for high-frequency blade based on noncontact vibration measurement and simulating calculation

Abstract

The invention discloses a modal analyzing method for a high-frequency blade based on noncontact vibration measurement and simulating calculation. The modal method can meet modal analysis in the high-frequency range from 1000 Hz to 15000 Hz, and comprises the following steps that firstly, a free mode and vibration mode are calculated by using a finite element calculation method; secondly, accordingto a free mode calculation result, a measurement point is selected, a blade origin frequency response function is measured by using a laser Doppler vibration measurement technology, and the actual inherent frequency of the blade is obtained; thirdly, the elasticity modulus and the Poisson's ratio parameter of a simulation model are corrected, so that the calculation result of the simulation modelis consistent with the actual inherent frequency, work boundary conditions are applied to the corrected simulation model, and the blade mode in a work state is calculated. By means of the method, theprecise modal frequency and vibration mode can be obtained for the high-frequency blade, and a reliable analysis reference is provided for engine blade resonance, fatigue failure and other faults.

Description

technical field [0001] The invention relates to a modal analysis method of a high-frequency blade, in particular to a modal analysis method of a high-frequency blade based on non-contact vibration measurement and simulation calculation. Background technique [0002] Faults such as resonance fatigue and block loss of centrifugal compressor blisks and centripetal turbine blisks are typical faults of micro-miniature aero-engines. From the perspective of resonance, in order to study and solve this fault, accurate modal analysis of the blades is a must. It is very necessary. Due to the small structure, complex profile and high natural frequency of centrifugal compressor blades and centripetal turbine blades, it is difficult to complete accurate modal analysis through conventional modal testing methods; at the same time, due to the parameters Errors, structural errors, and discrete errors exist objectively, and the calculation accuracy of the simulation model is also limited. Ther...

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Problems solved by technology

[0003] The technical problem to be solved by the present invention is to propose a high-frequency blade modal analysis method based on non-contact vibration measurement and simulation calculation for the above existing technical defects. Response function test, combined with modal simulation calculation, obtains accurate blade mode by correcting elastic modulus and Poisson's ratio parameters, and provides a reliable analysis benchmark for engine blade resonance, fatigue aging and other faults. The shortcomings of high test difficulty and poor accuracy caused by complex surface and high natural frequency also avoid simulation calculation errors caused by structure, parameters and discrete

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