某轻卡后牌照支架振动疲劳分析与参数优化

Vibration Fatigue Analysis and Parameters Optimization of A Light Truck Rear License Plate Bracket

为校核某轻卡后牌照支架的振动疲劳性能是否满足设计要求,首先建立后牌照支架有限元模型,对其进行模态性能分析。然后采集其激励端的振动加速度,再基于单位载荷对其进行频率响应分析,获取其x、y和z方向的应力传递函数,再基于功率谱密度函数对其进行振动疲劳分析。基于集成平台并且采用第二代非劣排序遗传算法对其结构参数进行优化分析。结果表明:其前两阶固有频率均高于路面激励频率,满足模态特性要求。疲劳寿命高于目标值,满足疲劳性能要求。优化之后其均符合模态性能和疲劳性能设计要求,并且其质量有所减轻,达到了轻量化的目的,最后其优化方案通过整车道路试验。

Aiming at checking the vibration fatigue performance of a light truck rear license plate bracket whether meet the design requirements,the finite element model for rear license plate bracket was established,and firstly,the modal performance analysis was carried out.Secondly,the vibration acceleration of the excitation end were collected,then the frequency response analysis was carried out based on unit load,the stress transfer functions of x,y and z directions were obtained.The vibration fatigue analysis was carried out based on power spectral density function.The structural parameters were optimized and analyzed based on integration platform by adopting integrated platform and non-dominated sorting genetic algorithm.The results show that its first two natural frequencies are higher than the road excitation frequency,which could meet the requirements of modal characteristics.Its fatigue life is greater than the target,which could meet the fatigue performance requirement.After optimization,the modal performance and fatigue performance could meet the design requirements,and its wear mass loss reduces,the lightweight purpose is achieved.Lastly,its optimized scheme successfully passes the vehicle road test.