A Parameter Identification Method for Vibration System of Resonant Fatigue Crack Growth Test Based on Soft Sensing Technology

Abstract

A method for identifying parameters of a resonant fatigue crack propagation test vibration system based on a soft sensing technology comprises the following steps: 1, establishing a system three-degree-of-freedom vibration mechanical model to obtain a kinetic equation, and deriving to obtain a system frequency equation about a relationship among the system inherent frequency, the spring rigidity and the particle mass; 2, calculating according to a finite element technology to obtain the rigidity of a test piece under different crack lengths, and testing the system resonant frequency when a crack is propagated to different lengths; 3, substituting the system resonant frequency value and the corresponding test piece rigidity under different crack lengths into the system frequency equation in order to obtain overdetermined equations about the mass to be identified and unknown rigidity; 4, solving the overdetermined equations through a least squares technique to obtain nonlinear equations about the mass and rigidity; and 5, solving the nonlinear equations by using a Newton-Raphson formula, and identifying the vibration system parameters comprising the mass and the rigidity. The method has the advantages of good maneuverability, low cost and good accuracy.

Description

technical field [0001] The invention relates to the technical field of vibration system parameter identification, in particular to a method for parameter identification of a resonance fatigue crack growth test vibration system based on soft sensor technology. Background technique [0002] The working performance of the electromagnetic resonance high-frequency fatigue testing machine directly affects the accuracy of the test results, that is, during the crack growth process, the natural frequency of the system is strictly tracked and the stability of the test load is controlled. In order to achieve this goal, it is necessary to establish a systematic Dynamic model, and accurate analysis of the dynamic characteristics of the system, it is first necessary to measure and calculate the particle mass and spring stiffness of the vibration system, but the particle of the vibration system is composed of many parts with different shapes and materials. The direct measurement of the par...

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Problems solved by technology

[0003] In order to overcome the deficiencies of poor operability, high cost and poor accuracy of the parameter identification method of the existing resonance fatigue crack growth test vibration system, the present invention provides a method with good operability, low cost and high accuracy. A good parameter identification method for the vibration system of resonant fatigue crack growth test based on soft sensor technology

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