发动机气缸盖热机疲劳寿命预测

车用发动机 ›› 2023, Vol. 0 ›› Issue (2) : 47-52.

栏目

发动机气缸盖热机疲劳寿命预测

曾小春¹，苗瑞刚¹，魏涛¹，景国玺^2,3，张执南⁴，郭荣⁵，孙帅^2,3

作者信息 +

Thermal-Mechanical Fatigue Life Prediction of Diesel Engine Cylinder Head

ZENG Xiaochun¹,MIAO Ruigang¹,WEI Tao¹,JING Guoxi^2,3,ZHANG Zhinan⁴,GUO Rong⁵,SUN Shuai^2,3

Author information +

文章历史 +

摘要

采用子模型方法和Sehitoglu模型对某增压柴油发动机气缸盖开展了详细的热机疲劳寿命预测研究。通过采用缸内燃烧模拟分析、水套冷却分析来为缸盖温度场分析提供热分析边界，冷却水侧采用FEA与CFD耦合计算分析方法，使得计算边界条件更加精确合理。基于有限元方法计算了整机标定工况和怠速工况下气缸盖温度和应力应变，采用子模型方法并考虑材料非线性获得了气缸盖在发动机冷热交替热冲击试验工况下的应力应变历程。基于Sehitoglu模型计算得到了气缸盖热机疲劳损伤和寿命，计算结果表明该气缸盖最小寿命为5 038次，位于第3缸火力面排气座圈附近，高于轻卡评价标准5 000次寿命要求，热机疲劳损伤中由温度因素主导的氧化损伤占主导作用，其次是机械损伤，蠕变损伤贡献最小。

Abstract

The sub-model method and the Sehitoglu model were used to carry out a detailed thermo-mechanical fatigue life prediction research on the cylinder head of a supercharged diesel engine. The thermal boundaries of cylinder head temperature field analysis were provided by using in-cylinder combustion simulation analysis and water jacket cooling analysis. The coupled calculation and analysis method of FEA and CFD for the cooling water side made the calculation boundaries more accurate and reasonable. Based on the finite element method, the temperature and stress-strain characteristics of cylinder head under rated and idle conditions were calculated, and the stress-strain history of cylinder head under hot and cold alternating thermal shock test conditions was obtained by using the sub-model method and considering the material nonlinearity. The thermalmechanical fatigue damage and life of cylinder head were calculated by the Sehitoglu model and the results show that the minimum life area of cylinder head was located near the exhaust seat ring of the third cylinder fire surface with the life of 5 038 cycles. The calculated life is higher than the 5 000 cycles of light truck evaluation standard. In the thermal-mechanical fatigue damage, the oxidation damage dominated by temperature factor plays a leading role, the mechanical damage follows, and the creep damage contributes the least.

导出引用

曾小春，苗瑞刚，魏涛，景国玺，张执南，郭荣，孙帅. 发动机气缸盖热机疲劳寿命预测[J]. 车用发动机. 2023, 0(2): 47-52

ZENG Xiaochun,MIAO Ruigang,WEI Tao,JING Guoxi,ZHANG ZhinanGUO Rong,SUN Shuai. Thermal-Mechanical Fatigue Life Prediction of Diesel Engine Cylinder Head[J]. Vehicle Engine. 2023, 0(2): 47-52