Print Email Facebook Twitter Computational investigation of porosity effects on fracture behavior of thermal barrier coatings Title Computational investigation of porosity effects on fracture behavior of thermal barrier coatings Author Krishnasamy, J. (TU Delft Aerospace Structures & Computational Mechanics) Ponnusami, Sathiskumar A. (City University London) Turteltaub, S.R. (TU Delft Aerospace Structures & Computational Mechanics) van der Zwaag, S. (TU Delft Novel Aerospace Materials) Date 2019 Abstract The influence of microstructural pore defects on fracture behaviour of Thermal Barrier Coatings (TBC) is analysed using finite element analysis involving cohesive elements. A concurrent multiscale approach is utilised whereby the microstructural features of the TBC are explicitly resolved within a unit cell embedded in a larger domain. Within the unit cell, a random distribution of pores is modelled along with three different layers in a TBC system, namely, the Top Coat (TC), the Bond Coat (BC) and the Thermally Grown Oxide (TGO). The TC/TGO and the TGO/BC interfaces are assumed to be sinusoidal of specified amplitude and frequency extracted from experimental observations reported in the literature. To simulate fracture in the TBC, cohesive elements are inserted throughout the inter-element boundaries in order to enable arbitrary crack initiation and propagation. A bilinear traction-separation relation with specified fracture properties for each layer is used to model the constitutive behaviour of the cohesive elements. Parametric studies are conducted for various pore geometrical features, porosity, fracture properties of Top Coat layer and Thermally Grown Oxide layer thicknesses. The results are quantified in terms of crack initiation and evolution. It is found that the presence of pores has a beneficial effect on the fracture behavior up to a certain value of porosity after which the pores become detrimental to the overall performance. Insights derived from the numerical results can help in understanding the failure behavior of practical TBC systems and further aid in engineering the TBC microstructure for a desired fracture behavior. Subject Cohesive elementsConcurrent multiscale modelFracturePorosityThermal barrier coatings To reference this document use: http://resolver.tudelft.nl/uuid:78c5d99f-e000-40d6-b007-3ee8d7b032c4 DOI https://doi.org/10.1016/j.ceramint.2019.07.031 Embargo date 2020-01-01 ISSN 0272-8842 Source Ceramics International, 45 (16), 20518-20527 Bibliographical note Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Part of collection Institutional Repository Document type journal article Rights © 2019 J. Krishnasamy, Sathiskumar A. Ponnusami, S.R. Turteltaub, S. van der Zwaag Files PDF 1_s2.0_S0272884219318504_main.pdf 2.12 MB Close viewer /islandora/object/uuid:78c5d99f-e000-40d6-b007-3ee8d7b032c4/datastream/OBJ/view