摩托车车架疲劳试验载荷谱的研究与编制

STUDY AND PROGRAMMING ON THE EXPERIMENTAL LOAD SPECTRUM FOR THE FATIGUE OF MOTORCYCLE FRAME

基于摩托车标准路面实测载荷数据的实际状况,提出一种基于消除趋势项、平滑和滤波等处理方式相结合的摩托车载荷数据信号预处理方法;在考虑摩托车疲劳试验台载荷输入方式的基础上,根据摩托车的使用工况,运用双参数雨流计数法,在实测载荷等效转换为多段等幅力激励载荷后,最终组编形成完整的多工况综合试验载荷谱。同时,采用LS-DYNA进行仿真计算应力,并运用Miner理论计算所编谱与实测谱的疲劳寿命进行对比,验证摩托车车架等效激励载荷谱的有效性。所编制的试验载荷谱具有多段等幅特点,其通用性强,适用于各类型疲劳耐久试验台的载荷加载。

A signal preprocessing method,combining trend elimination,smooth and filter,is proposed to process the load data of the motorcycle based on the collected data from a motorcycle frame moving on a real condition standard pavement.According to the work conditions and considering the load input mode of motorcycle fatigue test rig,the load spectrum is further programmed employing the two variable rain flow count method and transferring the measured data into equivalent multi-stage constant force excitation load.The stresses under the various loads in the spectrum are calculated using the LS-DYNA simulation.The fatigue life obtained from the programmed load spectrum is compared with that calculated from measured data using Miner theory,hence the accuracy and validation of the programmed load spectrum are verified.The programmed load spectrum is of multistage constant amplitude and universality,hence can be used as the load input for different kinds of fatigue test rig.