试车场实测载荷谱中含有大量的低幅值载荷,在进行载荷谱编辑处理时存在许多小载荷删除准则,而这些准则往往仅考虑小载荷是否造成损伤。考虑到低幅值载荷的强化效应,提出了一种新的小载荷删除准则。应用该准则对试车场实测载荷谱进行编辑处理,生成了加速谱。从幅值域(穿级计数、雨流计数),损伤域(损伤保留、雨流循环损伤分布),频率域(冲击响应谱、频域疲劳损伤谱)多方面对原始谱和加速谱进行了对比分析,结果表明该方法在保留损伤,保证损伤载荷分布特征和频域特征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。通过建立整车台架试验,验证了该耐久性试验载荷谱编制方法的可行性。
Loading spectrum acquired from proving ground contains a large percentage of low-amplitude loads. For accelerated durability test spectrum development,many small load omission criterions( SLOC) have been induced. However,only the damage effect of low-amplitude loads was considered. The strengthening effect was ignored in the traditional SLOCs. A new SLOC was induced by considering the strengthening effect. This criterion was applied to develop target spectrum of a certain load section from proving ground,and an accelerated spectrum was created. To verify the validness of this methodology,analyses of original spectrum and the accelerated spectrum were conducted from multi-aspects,including amplitude domain( level crossing counting and rain-flow counting),damage domain( damage reservation and rain-flow cycle damage distribution),and frequency domain( shock response spectrum and fatigue damage spectrum). The results show that the accelerated spectrum has reserved spectrum damage,guaranteed damage distribution characteristics and frequency characteristics. Finally,vehicle bench iteration test was conducted,and results show that original spectrum can be replaced by the accelerated spectrum as the durability test spectrum. The validness of this methodology has been demonstrated.