LOW CYCLE THERMAL FATIGUE OF THE ENGINE EXHAUST MANIFOLD

  • Choi, B.L. (Hyundai Motor Company) ;
  • Chang, H. (Hyundai Motor Company) ;
  • Park, K.H. (Hyundai Motor Company)
  • Published : 2004.12.01

Abstract

This paper presents the low cycle thermal fatigue of the engine exhaust manifold subject to thermo-mechanical 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.

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References

  1. John, H. B. (1990). An Introduction to the Design andBehavior of Bolted Joints. M. Dekker, New York and Basel
  2. Kawano, H., Inoue, S., Iwata, M., Yamaguchi, T.,Yanagisawa, H. and Fukumori, E. (1991). Improvementin the thermal elasto-plastic FEM model applied toexhaust manifold. SAE Paper No. 911771, 1-11
  3. Lederer, G., Charkaluk, E., Verger, L. and Constantinescu, A(2000). Numerical lifetime assessment of engine partssubmitted to thermomechanical fatigue. Application toExhaust Manifold Design, SAE Paper No. 2000-01-0789,1-7
  4. Littler, D. J. (1969). Thermal Stresses and Thermal Fatigue.Buttrerworths. London
  5. Manson, S. S. (1996). Thermal Stress and Low-CycteFatigue. McGraw-Hill. New York
  6. Noguchi, T., Yasuki, T., Nakakubo T. and Atsumi, T.(1985). Thermal stress and deformation analysis of exhaust manifold of internal-combustion engine. The Society of Automotive Engineers of Japan, Riview, 34-39
  7. Watanabe, Y., Shiratani, K., Iwanaga, S. and Nishino, K.(1999). Thermal fatigue life prediction for stainlesssteel exhaust manifold. SAE Paper No. 980841, 1-6