一种新的考虑伪损伤保留的道路载荷模拟试验加速方法

A NEW SPECTRUM DEVELOPMENT METHODOLOGY BASED ON PSEUDO DAMAGE RESERVING FOR ROAD LOAD SIMULATION TEST

试车场实测载荷谱含有大量的低幅值载荷,为删除小载荷进而加速试验,传统的载荷谱编制方法一般是基于应力应变的损伤编辑,而工程实际中应力应变信号往往很难获得。考虑到这种情况,提出了一种新的基于伪损伤保留的小载荷删除准则。针对某轿车前副车架的疲劳试验,应用该方法对其原始载荷谱进行编辑处理,生成伪损伤保留比例为90%的加速谱,从时域、幅值域和频率域三方面对原始谱和加速谱进行对比分析,结果表明该方法在保留载荷的损伤特性,保证载荷谱的统计特征、雨流矩阵特征和频率特征一致性的基础上实现了加速,加速谱可代替原始谱进行耐久性试验。最后建立台架试验,试验结果表明加速试验在有效节约试验时间的同时实现了与采用原始载荷谱试验的结果一致性,并验证了提出的耐久性试验载荷谱编制方法的合理性。

Loading spectrum collected from proving ground contains large amounts of low-amplitude loads. For accelerating test, low-amplitude loads should be removed. Traditional spectrum compilation method generally based on stress or strain damage editing. However, obtaining stress or strain signal from engineering practice is difficult. Considering this problem, this paper proposed a new criterion to remove low-amplitude loads based on pseudo damage reserving. Taking a vehicle sub-frame fatigue test as an example, 90% pseudo damage reserved spectrum is obtained by dealing with original load spectrum with this method. A comparison of accelerated load spectrum with original load spectrum was made in time, amplitude and frequency domains. It turned out that the accelerated load spectrum can be used for durability test instead of the original one. Finally, a bench test was conducted. The result shows the consistency of accelerated load spectrum and original load spectrum on the premise of saving durability test time. Also, the rationality of the load spectrum compilation method proposed in this paper was verified.