Comprehensive Numerical Simulation of Stress and Damage Fields under Thermo-Mechanical Loading for TBC-Coated Ni-Based Superalloy

Abstract:

A finite element analysis code was developed to accurately predict stress and damage fields in thermal barrier coatings (TBCs) systems subjected to thermo-mechanical loadings. An inelastic constitutive equation for TBCs, and a Chaboche-type viscoplastic constitutive equation for Ni-based super alloys (IN738LC) were employed to simulate high temperature creep and cyclic deformation. Simulations of the TBC/IN738LC system subjected to two types of loading, namely, a triangle-wave loading and a GT-operation loading, were performed using the developed analysis code. The results confirmed that the stress and damage fields in the TBC/IN738LC system could be simulated accurately, and provided us with credible results regarding the crack occurrence. Additionally, the analysis under the GT-operation loading conditions revealed that a peak stress generated during the start-up operation would lead to delamination of the TBC, while a peak stress at the shut-down would lead to cracking in the substrate.

• Periodical: Key Engineering Materials (Volume 774)
• Pages: 137-142
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.774.137
• Online since: August 2018
• Authors: Hiroaki Katori, Masayuki Arai, Kiyohiro Ito
• Keywords: Finite Element Method, Gas Turbine, Inelastic Constitutive Equation, Thermal Barrier Coatings, Thermo-Mechanical Loading

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