汽车发动机膨胀水箱有限元分析与研究

CAE Analysis and Research on Expansion Tank of Automobile Engine

摘要: 为提高汽车发动机膨胀水箱的结构强度，降低故障率，本文通过建立膨胀水箱三维模型，利用Ansys有限元分析软件对膨胀水箱进行有限元分析。考虑到路面不平度与发动机的工作频率激励的影响，对膨胀水箱进行谐响应分析和随机振动分析，根据分析结果对水箱结构加以改进并进行了分析验证。有限元分析结果表明，膨胀水箱上部安装支架处及内部隔板处为薄弱位置，且膨胀水箱在264 Hz时上下方向易产生共振导致产生较大应力，存在发生结构损坏的可能性。验证结果表明水箱改进方案能明显降低水箱所受等效应力与变形量，为膨胀水箱的设计与结构改进提供了一定的参考价值。

Abstract: In order to improve the structural strength of the expansion tank of automobile engine and reduce the failure rate, this paper establishes a three-dimensional model of the expansion tank and carries out finite element analysis on the expansion tank by using Ansys finite element analysis software. Considering the influence of road roughness and engine working frequency excitation, the harmonic response analysis and random vibration analysis of the expansion water tank are carried out, and the structure of the water tank is improved and verified according to the analysis results. The results of finite element analysis show that the upper mounting bracket and the internal partition of the expansion tank are weak positions, and the expansion tank is prone to resonance in the up and down direction at 264 Hz, resulting in greater stress, which may lead to structural damage. The verification results show that the improvement scheme of water tank can obviously reduce the equivalent stress and deformation of water tank, which provides certain reference value for the design and structural improvement of expansion water tank.