中型货运汽车车架结构静力学及模态的有限元分析

Finite Element Analysis of Static and Modal Analysis of the Frame Structure of Medium-Sized Freight Vehicles

摘要: 车辆在行驶过程中，车架不仅要承受各种载荷与力矩，还不停地受到来自汽车内部以及路面激励而产生振动，这就对车架本身的刚强度以及振动特性提出了较高的要求。本文采用有限元分析方法对两款中型货车车架的刚强度以及振动模态进行分析。基于两款已有中型货车车架，分别建立了两款车架的有限元模型。接着对两款车架进行了模态分析，并分别提取了前六个阶模态频率及模态振型。基于汽车行驶过程中的四种常见工况对两款车架进行了强度分析。介绍了车架弯曲刚度及扭转刚度的计算方法，并基于此方法对两款车架进行了弯曲刚度及扭转刚度计算，根据强度及刚度分析结果给出了改进方案，最后通过有限元方法验证了两款车架的改进效果，经检验，改进结果合理。

Abstract: During the driving process of a vehicle, the frame not only bears various loads and moments, but also continuously vibrates due to internal and road excitation, which puts high requirements on the stiffness, strength, and vibration characteristics of the frame itself. This article uses finite element analysis method to analyze the stiffness, strength, and vibration modes of two medium-sized truck frames. Based on two existing mid size truck frames, finite element models were established for each frame. Subsequently, modal analysis was conducted on the two frames, and the first six modal frequencies and vibration modes were extracted separately. A strength analysis was conducted on two frames based on four common operating conditions during car driving. The calculation methods for the bending and torsional stiffness of the frame were introduced, and based on this method, the bending and torsional stiffness of two frames was calculated. Based on the analysis results of strength and stiffness, improvement plans were proposed. Finally, the improvement effect of the two frames was verified by finite element method, and the improvement results were reasonable after inspection.