High temperature components in internal combustion engines and exhaust systems must withstand severe mechanical and thermal cyclic loads throughout their lifetime. The combination of thermal transients and mechanical load cycling results in a complex evolution of damage, leading to thermomechanical fatigue (TMF) of the material. Analytical tools are increasingly employed by designers and engineers for component durability assessment well before any hardware testing. The DTMF model for TMF life prediction, which assumes that micro-crack growth is the dominant damage mechanism, is capable of providing reliable predictions for a wide range of high-temperature components and materials in internal combustion engines. Thus far, the DTMF model has employed a local approach where surface stresses, strains, and temperatures are used to compute damage for estimating the number of cycles for a small initial defect or micro-crack to reach a critical length. In the presence of significant gradients of stresses, strains, and temperatures, the use of surface field values could lead to very conservative estimates of TMF life when compared with reported lives from hardware testing. As an approximation of gradient effects, a non-local approach of the DTMF model is applied. This approach considers through-thickness fields where the micro-crack growth law is integrated through the thickness considering these variable fields. With the help of software tools, this method is automated and applied to components with complex geometries and fields. It is shown, for the TMF life prediction of a turbocharger housing, that the gradient correction using the non-local approach leads to more realistic life predictions and can distinguish between surface cracks that may arrest or propagate through the thickness and lead to component failure.


    Zugriff

    Zugriff prüfen

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    A Mechanism-Based Thermomechanical Fatigue Life Assessment Method for High Temperature Engine Components with Gradient Effect Approximation


    Weitere Titelangaben:

    Sae Technical Papers


    Beteiligte:
    Kassir, Abdallah (Autor:in) / Sethy, Asok (Autor:in) / Chang, Cherng-Chi (Autor:in) / Hazime, Radwan (Autor:in) / Seifert, Thomas (Autor:in)

    Kongress:

    WCX SAE World Congress Experience ; 2019



    Erscheinungsdatum :

    2019-04-02




    Medientyp :

    Aufsatz (Konferenz)


    Format :

    Print


    Sprache :

    Englisch






    Prediction of duration of life of automotive components under thermomechanical fatigue

    Ahdad, F. / Soare, M. A. / Institution of Mechanical Engineers | British Library Conference Proceedings | 2002



    Effect of Temperature Cycle on Thermomechanical Fatigue Life of a High Silicon Molybdenum Ductile Cast Iron

    Engler-Pinto, Carlos / Pan, Jwo / Avery, Katherine | SAE Technical Papers | 2015