摘要
汽车导流罩结构强度优化设计的作用是为了使导流罩的各项性能满足设计要求,难点技术在于强度性能、模态性能和气动阻力性能难以获取,提出基于有限元方法对导流罩进行振动强度仿真,分析结果表明导流罩的最大应力小于材料许用应力,位于左前安装基座附近。导流罩支架的最大应力超过材料屈服强度,位于中间连接支架折弯处。通过对该支架进行优化,分析结果表明优化之后该支架的最大应力小于材料屈服强度,降低率明显,其重量也减轻了。对导流罩进行约束模态仿真,分析结果表明其前四阶模态频率均大于发动机怠速激励频率,有效地避开了共振频率。采用RNGκ-ε模型对导流罩进行气动阻力仿真,其气动阻力系数在工程经验要求值之内。各项仿真分析结果表明该导流罩的各强度性能、模态性能和气动阻力性能均满足设计要求。
To satisfy design requirement of structural strength for vehicle dome, simulation of vibration intensity is carried out for the dome based on finite element method. According to analysis results, it is proved that the maximum stress of the dome is less than allowable stress of material, and the maximum stress is located near front left mounting base, while the maximum stress of dome support exceeds yield strength of material and the maximum stress of dome support is located in bend of middle attachment bracket. Optimization is carried out for the bracket. It is suggested that the maximum stress of the optimized bracket is less than yield strength of material and reduction rate is obvious. The bracket weight is also reduced. A constraint mode is carried out for the dome. It is proved that the modal fre- quency of first four - order exceeds excitation frequency of engine idle speed, which avoids resonant frequency effec- tively. RNGK- 8model is u^ed to carry out aerodynamic resistance simulation for the dome and aerodynamic resist- ance coefficient is within the required value of engineering experience. All results of simulation analysis show that performance of strength, modality and aerodynamic resistance can satisfy design requirement.
作者
胡勇
Hu Yong(School of Transportation and Logistics, East China Jiaotong University, Nanehang Jiangxi 330013, China)
出处
《计算机仿真》
北大核心
2017年第10期127-131,216,共6页
Computer Simulation
关键词
导流罩
有限元
强度
模态
气动阻力
Dome
Finite element
Strength
Modality
Aerodynamic resistance
