某型乘用车发动机支架的模态分析与拓扑优化

Modal Analysis and Optimization of Engine Bracket for Passenger Vehicle

发动机支架是连接汽车发动机附件和发动机的重要部件,为了保证发动机支架在工作过程中不会与发动机系统发生共振现象及轻量化要求,以某型乘用车发动机支架为研究对象,建立模态分析数学模型,得到计算方程;将发动机支架三维模型导入有限元软件中进行模态分析,得到前6阶支架结构的固有频率及主振型;根据对支架的减重优化要求,对支架三维结构进行拓扑优化,并以模态分析结果为参考,对拓扑优化后的模型进行后处理,得到优化后的发动机支架模型,并进行仿真分析验证,最终满足要求。结果表明,优化后的发动机支架的固有频率高于发动机频率,可避免发生共振现象,保证发动机支架的正常工作。

Engine bracket is an important part connecting automobile engine accessories and engine.In order to ensure that the engine bracket will not resonate with the engine system in the process of working and will meet the requirements of lightweight,the engine bracket of a passenger car was taken as the research object to establish a mathematical model of modal analysis and obtain the calculation equation.The 3 dmodel of engine bracket was imported into finite element software for modal analysis,and the natural frequency and main mode of the first 6 stages of bracket structure were obtained.According to the requirements of weight reduction optimization for the bracket,the three-dimensional structure of the bracket was topologically optimized,and the model after topological optimization was processed with the results of modal analysis as reference to obtain the optimized engine bracket model,which was verified by simulation analysis and finally met the requirements.The study results show that the natural frequency of the optimized engine support is higher than that of the engine,which can avoid resonance and ensure the normal operation of the engine support.