基于模型确认的非线性转子支承系统建模方法  

A Nonlinear Modeling Method for a Rotor-Support System Based on Model Validation

作　　者：杨稀 闫述 王浩然 赵永刚 YANG Xi;YAN Shu;WANG Hao-ran;ZHAO Yong-gang(AECC Shenyang Engine Research Institute,Shenyang 110015,China)

机构地区：[1]中国航发沈阳发动机研究所,沈阳110015

出　　处：《航空发动机》2025年第1期151-157,共7页Aeroengine

基　　金：航空动力基础研究项目资助。

摘　　要：为了建立能够准确反映转子支承系统真实结构的数学模型,提出基于模型确认辨识转子系统非线性支承刚度参数,并建立转子支承系统的非线性动力学模型的方法。采用自由状态下的转子模态测试数据对转子模型进行修正与确认,建立准确的转子模型。在此基础上,对转子支承系统开展低幅值激励的模态测试,辨识其线性支承刚度参数,从而建立转子支承系统的底层线性模型。对转子支承系统开展不同激励水平下的恒位移振动测试,确定支承非线性刚度的函数形式,并进一步识别支承非线性刚度参数,最终建立转子支承系统的非线性动力学模型。设计加工了考虑非线性支承因素的转子系统,采用该方法建立的转子支承系统底层线性模型,与实际结构的模态频差在5%以内,模态置信准则(MAC)值在0.89以上,具有良好的相关性;进一步建立转子支承系统的非线性动力学模型,将模型预测的响应与转动试验数据进行对比,结果表明:所提出的方法能够基本准确地反映真实结构的非线性动力学特性。To establish a mathematical model that accurately reflects the real structure of the rotor-support system,a method based on model validation was proposed to identify the nonlinear support stiffness parameter and establish the nonlinear dynamic model for a rotor-support system.An accurate rotor model was established by using free-state rotor modal test data to modify and validate the rotor model.On this basis,low amplitude excitation modal tests were carried out on the rotor-support system to identify the linear support stiffness parameters,thereby the underlying linear model for the rotor-support system was established.The constant displacement vibration tests under different excitation levels were carried out on the rotor-support system to determine the functional form of the nonlinear support stiffness and further identify the nonlinear support stiffness parameters.Finally,the nonlinear dynamic model for the rotor-support system was established.A rotor system considering nonlinear support factors was designed and fabricated,and vibration tests were conducted,the model-predicted responses were compared with test data,the results show that for the established linear model,the modal frequency differences are within 5%,and the Modal Assurance Criterion(MAC)values are above 0.89,showing good correlations;the established nonlinear model can accurately reflect the nonlinear dynamic characteristics of the real structure.

关 键 词：转子支承系统 非线性支承 振动测试 非线性参数识别 非线性建模 模态置信准则 航空发动机 

分 类 号：V231.9[航空宇航科学与技术—航空宇航推进理论与工程]