排气歧管热疲劳失效研究

Study on Thermal Fatigue Failure of Exhaust Manifold

针对某柴油机在市场和试验过程中出现的排气歧管开裂问题进行分析。材料分析为热疲劳开裂,裂纹由排气歧管外侧向内壁扩展至开裂。计算表明排气歧管发生裂纹位置等效塑性应变偏大,应力幅值较高。通过计算仿真不同结构排气歧管应力,并通过试验优化排气歧管,从而解决排气歧管热疲劳问题。

After the exhaust manifold cracking failure appears in the market and test,through material analysis,the reason is found to be thermal fatigue.The crack extends from outside to inner wall until cracking location.The CAE results show that the equivalent plastic strain and stress amplitude of the cracking location is larger.In this paper,the exhaust manifold of different structure is compared by CAE and test to solve exhaust manifold thermal fatigue problem.