Numerical lifetime assessment of engine parts submitted to thermomechanical fatigue

Guy Lederer (1) , Eric Charkaluk (1) , Laetitia Verger (2) , Andrei Constantinescu (1)

1 LMS - Laboratoire de mécanique des solides
2 PSA - PSA Peugeot - Citroën

In this work a numerical method for the design of components submitted to severe cyclic thermomechanical loading is developed. This tool is based on a Finite Element (FE) analysis. In a first part the temperature distribution is obtained and used in the second part for the mechanical computation. The analyses use the description of the geometry of the part, a precise information of the thermal properties, an appropriate behavior of the material at low and high temperature and a good assessment of the boundary conditions (heat transfer coefficients, contact, …). This method is applied to asses the low cycle fatigue design of a diesel turbo-charged exhaust manifold in cast iron. These calculations, failure location and lifetime estimation, obtained on two versions of this component, are compared to experimental data. The results show a good agreement in terms of critical zones location and of lifetime comparison in both versions and permit thus to classify the versions.

Domaines: Mécanique des solides [physics.class-ph]

Guy Lederer, Eric Charkaluk, Laetitia Verger, Andrei Constantinescu. Numerical lifetime assessment of engine parts submitted to thermomechanical fatigue: Application to exhaust manifolds design. SAE 2000 World Congress, Mar 2000, Detroit, United States. ⟨10.4271/2000-01-0789⟩. ⟨hal-00116123⟩