有限元网格划分对模态计算精度的影响研究

Study on Impact of the Finite Element Meshing on Modal Calculation Accuracy

基于铁路货车平车车体结构,深入研究了有限元网格的类型和尺寸选择对车体模态计算结果的影响。通过有限元仿真计算分析的方式获取了车体模态频率,对不同网格大小和网格类型下的模态计算结果进行了差异化分析,提出了用于车体模态计算较为适宜的网格划分方法。不同网格大小和网格类型的模态计算结果,其各阶频率存在差异,但振型基本一致。在计算精度与时间成本的双重因素考虑下,对于车体板材和型材结构件,建议整体采用线性四边形单元进行网格划分,单元尺寸宜控制在50 mm以内。为后续同类车体有限元模态计算效率和计算精度的提升提供了参考依据。

This article studies in depth the impact of type and dimension selection of the finite element mesh on the modal calculation result of the carbody based on the carbody structure of a railway flat car.It obtains the modal frequency of the carbody by finite element simulation calculation and analysis,describes the differentiation analysis of the modal calculation results for different sizes and types of meshes,and proposes a more appropriate meshing method for the modal calculation of the carbody.The modal calculation results for different sizes and types of meshes present different frequency levels,but their modes of vibration are consistent.Considering both factors of calculation accuracy and time cost,it's recommended to use linear quadrilateral elements for meshing the structural components of a carbody made of plates and profiles,and the size of the element is limited to 50 mm.This article provides a reference for improving the efficiency and accuracy of the finite element modal calculation of similar carbodies in the future.