摘要
传统的基于频响函数(frequency response function,简称FRF)的模型修正方法在测试噪声较大、初始分析频响与测试频响残差较大、待修正参数较多等情况下不易收敛,为此提出了一种采用移频技术的极大似然估计有限元模型修正方法。首先,利用“先验”的频响函数方差信息,构造极大似然估计器,迭代求得最优的待修正参数估计;其次,在迭代方程中引入移频方法,采用总体最小二乘平差方法计算方程的解,以提高参数识别的收敛性和稳定性;最后,根据频率点的筛选准则剔除数据,采用一种高精度的频响扩充方法以减小扩充所带来的额外误差。列车转向架构架仿真算例和三角机翼飞机测试模型的修正结果表明,该方法抗噪性较强,在复杂情况下仍可以得到较好的修正结果。
The traditional model updating method based on frequency response function(FRF)is difficult to converge in case of large test noise,large residual between initial analysis FRF and test FRF,or large number of parameters to be modified.A dynamic finite element model(FEM)updating method based on maximum likelihood estimation and frequency shift is presented.The maximum likelihood estimator using"a priori"variance information of the FRF is constructed to obtain the optimal parameter estimation depending on the Gauss-Newton method.The frequency shift method and the total least square adjustment method are used to solve the iterative equation to improve the robustness of parameter identification.The test data of poor quality is eliminated according to selection criterion of frequency points.An approach for expanding incomplete experimental FRF is presented to reduce the extra error.Finally,numerical simulation and experimental investigation for updating the dynamic finite element model of a bogie structure and an aircraft model are performed to validate the robustness and efficiency of the present method.The obtained results show that the present method can be successfully applied to update the complex finite element models.
作者
范新亮
王彤
夏遵平
FAN Xinliang;WANG Tong;XIA Zunping(State Key Laboratory of Mechanics and Control of Mechanical Structures,Nanjing University of Aeronautics and Astronautics Nanjing,210016,China)
出处
《振动．测试与诊断》
EI
CSCD
北大核心
2021年第4期797-805,837,共10页
Journal of Vibration,Measurement & Diagnosis
基金
航空科学基金资助项目(20161352011)
江苏高校优势学科建设工程资助项目。
关键词
模型修正
频响函数
极大似然估计
移频方法
抗噪性
model updating
frequency response function(FRF)
maximum likelihood estimation
frequency shift method
the noise resistance
作者简介
第一作者:范新亮,男,1993年6月生,硕士生。主要研究方向为动力学模型修正与确认。E-mail:1036838049@qq.com;通信作者:王彤,男,1978年1月生,博士、副教授。主要研究方向为振动测试、信号分析、模型修正等的研究、开发与应用。E-mail:wt78@nuaa.edu.cn。
