汽车试验场载荷谱等效分析技术研究

Study on Equivalent Analysis of Road Load Spectrum on Proving Grounds

为将A试验场已知路试规范等效地转移到B试验场,利用某SUV车型的A和B试验场载荷谱,进行分类和等效分析。针对模拟山路和高环工况,由于两试验场的路面构造一致,所以在B试验场中直接沿用A试验场规范;针对强化坏路工况,选择55个等效通道,基于伪损伤一致原则进行等效分析,并制定B试验场路试规范。在确保伪损伤一致性的情况下,部件真实损伤也一致,先将目标随机载荷进行雨流计数,得到幅值与频次在双对数坐标系下的关系曲线,定义计算伪损伤的S-N曲线斜率为经过该曲线高幅值区域内最多点直线的斜率,同时S-N曲线截距是该曲线中最大幅值的10倍。最终通过对等效通道的伪损伤,以及雨流统计频次曲线和穿级计数曲线的对比,验证了等效分析的有效性。

In order to transfer the known road test specifications from the proving ground A to the proving ground B,the classification and equivalent analysis were carried out based on the road load spectrum of a SUV vehicle on the both proving grounds. For the simulated mountain and highway roads,due to the pavement structures were consistent on the two proving grounds,the related specifications could be directly used on the proving ground B. For the strengthened road,55 equivalent load spectrum channels were selected,the equivalent analysis was conducted based on the principles of pseudo damage agreement,and then the related road test specifications of proving ground B were formulated. To ensure the consistency of the real component damage under the consistency of the pseudo damage,the relation between the amplitude and frequency was obtained in a log-log graph by using the rainflow counting method. The slope of S-N curve for the pseudo damage was defined as the slope of the straight line which passing through the most points in the high-amplitude region. The intercept of S-N curve was 10 times the value of the maximum amplitude. Finally,the effectiveness of the equivalent analysis was verified by comparing the pseudo damage,the statistical frequency curve of the rainflow counting and the curve of the level-crossing counting.