Modeling oxidation and plasticity induced damage in thermal barrier coatings (TBCS)

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Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Bilimleri Enstitüsü, Türkiye

Tezin Onay Tarihi: 2020

Tezin Dili: İngilizce

Öğrenci: FERİT SAİT

Asıl Danışman (Eş Danışmanlı Tezler İçin): Ercan Gürses

Özet:

Computational analysis and simulation of multi-physics phenomena taking place in coating systems is still a challenging task. Specifically, for ceramic coatings used as protective systems for base materials against elevated temperatures, known as thermal barrier coating (TBC) systems, construction of continuum level models which can express coupled nonlinear phenomena has attracted great attention. Thermal stresses, oxidation, creep and numerous other mechanisms and phenomena make it even harder to model and simulate the behavior of TBCs and bring a need for the development of premier models. In this effort, a new numerical model that allows simulation of oxidation and thermally grown oxide (TGO) in bond-coat is presented. Phase field theory is used with finite strain formulation and implemented using user element subroutine (UEL) in ABAQUS software for the finite element method. Results are compared with experimental data available for TGO in the literature. Initiation and development of damage were also modeled considering plasticity induced failure. Results were also compared with experimental data available for damage and stress development in isothermal conditions.