有限元-模态实验混合模型的薄壁件模态参数辨识方法

Identification Method of Modal Parameters of Thin-walled Parts Based on Mixed Model of Finite Element and Modal Experiment

笔者基于ANSYS有限元软件对工件系统进行模态分析求解系统模态振型,在有限元模态分析的基础上进行模态参数辨识,利用MATLAB对系统进行参数辨识得到系统理论频响函数,并根据实际测量的频响数据通过频域辨识方法进行拟合分析,得到系统理论与实测频响曲线以及系统模态固有频率,最后对比分析模态参数表示方法的准确性与实用性。相关研究结论能够为提高薄壁零件加工精度与效率提供依据。

With the development of finite element theory,numerical calculation and analysis methods based on finite element have been widely used in various industries.The processing of aeronautical thin-walled workpieces has become a technical problem in many aerospace manufacturing.Based on ANSYS finite element software,the modal analysis of the workpiece system can solve the system natural frequency and modal vibration mode,which can be obtained from the system under different frequency vibrations The vibration form determines the dangerous position.By modeling and analyzing different systems through MATLAB numerical calculation tools and solving the system modals,the vibration characteristics of the simple two-degree-of-freedom system and the rectangular thin plate system can be observed,providing a theoretical vibration mode basis.Based on the finite element modal analysis,the modal parameters are identified,and the system is used to identify the parameters of the system to obtain the theoretical frequency response function of the system.According to the actual measured frequency response data,the frequency domain identification method is used to perform fitting analysis to obtain The comparison between system theory and actual measured frequency response curve and system modal natural frequency can analyze the accuracy and practicability of the modal parameter representation method.The related research conclusions can provide the basis for improving the machining accuracy and efficiency of thin-walled parts.