柴油机高压油管加速载荷谱编辑研究

Study on Acceleration Load Spectrum Editing of Diesel Engine's High-pressure Fuel Pipes

针对高压油管耐久性试验耗时长的特点,研究高压油管加速疲劳试验在振动试验台上的应用。基于损伤等效原则,提出振动疲劳加速载荷谱编辑方法并对高压油管实测载荷谱进行编辑。对比加速载荷谱与原始载荷谱作用下的高压油管疲劳寿命,验证加速载荷谱编辑方法及其在振动试验台上应用的可行性。结果表明:柴油机高压油管疲劳失效属于高周疲劳,其所受载荷中存在大量小载荷循环,将小载荷循环进行删除可保证在失效位置及失效形式一致的情况下,极大程度地缩短疲劳试验时间和成本。

Due to the disadvantage of time-consuming of durability test of the high-pressure fuel pipes,the application of accelerating fatigue test method to the vibration test platform for the high pressure pipes is studied.Based on the equivalent damage assumption,the methods of editing acceleration load spectrum is put forward,and the testing load spectrum of the high-pressure fuel pipe is edited.Comparing the fatigue life result of the high-pressure fuel pipe acted by the acceleration load spectrum with that by the original load spectrum,the feasibility of application of this method in vibration test platform is proved.Results show that the fatigue failure of diesel engine’s high-pressure pipes belongs to highly cyclic fatigue.There is a large number of invalid loading cycles in the load spectrum which can be deleted to greatly save the fatigue test time and cost.Deleting the invalid loading cycles also can ensure the location and modes of failure unchanging during the durability tests.