基于多体动力学的车辆悬架控制臂载荷谱混合分布外推研究  

Hybrid Extrapolation of Vehicle Suspension Control Arm Load Spectrum Based on Multibody Dynamics

作　　者：董国疆[1] 杜飞 王威[1] 张龙升 DONG Guo-jiang;DU Fei;WANG Wei;ZHANG Long-sheng(Hebei Key Laboratory of Special Delivery Equipment,Yanshan University,Qinhuangdao 066004,Hebei,China)

机构地区：[1]燕山大学河北省特种运载装备重点实验室,河北秦皇岛066004

出　　处：《中国公路学报》2020年第7期186-196,共11页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51775481)。

摘　　要：试验场强化路载荷谱外推全寿命载荷谱是汽车构件疲劳耐久性能评判准确性的关键因素,针对参数法外推单分布估计的局限性,引入混合分布估计描述载荷谱多峰或复杂分布的综合特征。基于试验场强化路实车测试,应用多体动力学与有限元联合仿真,提取控制臂危险点应力谱;分别应用单分布和混合分布法解算应力谱拟合优度,以此为据选取应力谱最优均值、幅值概率密度并将应力谱循环外推至106次,应用FKM平均应力修正法编制8级应力谱,依据Miner准则分别从载荷幅值分布、损伤分布以及总损伤量等方面对单分布与混合分布外推应力谱进行综合分析。研究结果表明:应用拟合优度能较好评估两分布对应力谱均、幅值拟合程度,混合分布拟合效果优于单分布,拟合优度均为98%,对应力谱分布特征描述更为精确,可为外推提供较真实的载荷分布概率密度,从而提高外推载荷谱精度;比较应用2种分布拟合的外推载荷谱,损伤分布趋势相近,中级载荷损伤占比高,单分布外推载荷谱总损伤量为6.3×10-4,大于混合分布外推载荷谱总损伤为5×10-4,寿命预测偏于保守,导致耐久性设计裕度较大,应用混合分布外推能提高耐久性评估与轻量化设计精度。The proving-ground load spectrum extrapolation life load spectrum is a key factor in evaluating the fatigue durability of automobile components.In this paper,mixed distribution estimation is introduced to describe the comprehensive characteristics of multi-peak or complex distribution of a load spectrum,focused on the limitation of parameter extra-judicial single distribution estimation.Based on The real vehicle test on intensified road in the proving ground,the stress spectrum of the dangerous point of the control arm was extracted using the joint simulation of multi-body dynamics and finite element method.The single distribution method and the mixed distribution method were used to calculate the suitability of the stress spectrum fit.According to this,the optimal mean value of the stress spectrum and the probability density of the stress spectrum were selected and extrapolated to 106 times.The eight-order stress spectrum was compiled by the FKM average stress correction method.The extrapolation stress spectrum of a single distribution and mixed distribution were comprehensively analyzed from the aspects of load amplitude distribution,damage distribution,and total damage,according to the Miner criterion.The results show that the suitability of the fit can better evaluate the corresponding force spectrum of the two distributions and degree of amplitude fitting.Furthermore,the fitting effect of the mixed distribution is better than that of the single distribution,and the suitability of the fit is 98%.The description of the distribution characteristics of the stress spectrum is more accurate,which provides a more real probability density of load distribution for extrapolation,to improve the accuracy of the extrapolation load spectrum.Compared with the extrapolation load spectrum fitted by the two kinds of distribution,the damage distribution trend is similar;the intermediate load damage ratio is high;the total damage amount of the single distribution extrapolation load spectrum is 6.3×10-4,which is larger than the

关 键 词：汽车工程 载荷谱外推 混合分布估计 多体动力学仿真 疲劳损伤 

分 类 号：U467[机械工程—车辆工程]