An Analysis Method of Rotor Critical Speed ​​Based on Probability Box Framework

Abstract

The invention provides an analysis method for the critical rotational speed of a rotor based on a probability box frame, and relates to the bearing-rotor system dynamics. The method includes the steps of establishing a finite element model of a structure; describing a bearing support and other boundary conditions of the rotor as spring stiffness and damping in two directions; quantifying the uncertainty of each input parameter; calculating the critical speed of a rotor system under different parameter combinations through commercial finite element software; using a probability box method to analyze experimental results. The probability box can simultaneously describe the problems which simultaneously exist in stochastic uncertainty and cognitive uncertainty; existing probability models, interval numbers and evidence structures can be directly transformed into the form of probabilistic boxes, and the uncertainty described by the probability box is in accordance with engineering customs, and can be easily accepted and used by engineering personnel.

Description

Technical field [0001] The invention relates to the dynamics of a bearing-rotor system, in particular to a method for analyzing the critical speed of a rotor based on a probability box frame. Background technique [0002] Bearing-rotor system dynamics is a discipline that includes dynamic response, vibration, strength, fatigue, stability, reliability, condition monitoring, fault diagnosis and control [1-5]. In the calculation of rotor dynamics, regardless of whether the transfer matrix method or the finite element method is used, the rotor support is usually described by spring stiffness and damping, so the dynamic characteristics of the rotor system boil down to solving the eigenvalues ​​and response problems of a mechanical system [3 ]. With the continuous development of finite element software, many commercial finite element software have added rotor dynamics modules, so rotor dynamics analysis methods based on finite element methods have also received more and more attention...

AI Technical Summary

Problems solved by technology

However, in the process of research, many scholars often only study the influence of random uncertainty, interval uncertainty or fuzzy uncertainty on the critical speed and unbalance response of the rotor system. For the aeroengine rotor system, not only There are random uncertainties such as material parameters, and cognitive uncertainties such as connector stiffness and support stiffness, so the same uncertainty description alone cannot reflect the actual physical structure, so it is necessary to study both random and Cognitive Uncertainty of Engine Rotordynamic Characteristics

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