|
International Journal of Automotive Technology 2004;5(4): 297-302. |
LOW CYCLE THERMAL FATIGUE OF THE ENGINE EXHAUST MANIFOLD |
B. L. CHOI, H. CHANG, K. H. PARK |
Hyundai Motors |
|
|
|
ABSTRACT |
This paper presents the low cycle thermal fatigue of the engine exhaust manifold subject to thermomechanical cyclic loading. As a failure of the exhaust manifold is mainly caused by geometric constraints of the less expanded inlet flange and cylinder head, the analysis is based on the exhaust system model with three-dimensional temperature distribution and temperature dependent material properties. The result show that large compressive plastic deformations are generated at an elevated temperature of the exhaust manifold and tensile stresses are remained in several critical zones at a cold condition. From the repetition of these thermal shock cycles, maximum plastic strain range (0.454%) could be estimated by the stabilized stress-strain hysteresis loops. It is used to predict the low cycle thermal fatigue life of the exhaust manifold for the thermal shock test. |
Key Words:
Exhaust manifold, Thermal shock test, FEM, Plastic strain range, Thermal fatigue life |
|
|
|