基于柴油机考核工况的活塞高周疲劳寿命预测

针对柴油机台架耐久性试验规范规定的柴油机考核方法及工况,建立了多工况循环载荷作用下活塞高周疲劳寿命预测流程;采用Abaqus有限元分析软件建立活塞温度及应力计算模型,通过与试验数据对比进行模型标定,计算了各工况下活塞温度场及应力;采用Femfat软件考虑温度场及各种修正因素的影响对活塞单工况下高周疲劳寿命进行预测,采用双线性累积损伤准则对柴油机考核工况下活塞疲劳寿命进行预测。结果表明:采用双线性累积损伤准则可便捷地进行多工况周期性载荷下活塞高周疲劳寿命预测;活塞冷却油腔位置处寿命最低,但可满足柴油机考核使用要求。

High Cycle Fatigue Life Prediction of Piston Based on Acceptance Test of Diesel Engine

The high cycle fatigue life(HCFL) prediction workflow was established according to the method and conditions reg -ulated by the endurance test criterion of diesel engine .The Abaqus FEA software was employed to build the thermal and stress analysis model ,which was calibrated with the test data .Then the thermal and stress calculation of each condition were carried out .Considering the effects of thermal and other modified factors ,the HCFL of each condition was predicted using Femfat software and the HCFL based on acceptance test of diesel engine was predicted by means of double linear cumulative damage rule .The results indicated that the double linear cumulative damage rule could predict the HCFL of piston under cyclic and multiple load conditions .According to the analysis ,the life of the piston cooling gallery was the shortest ,but could meet the test requirements of the diesel engine .