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Computational investigation of porosity effects on fracture behavior of thermal barrier coatings. / Krishnasamy, Jayaprakash; Ponnusami, Sathiskumar A.; Turteltaub, Sergio; van der Zwaag, Sybrand.

In: Ceramics International, Vol. 45, No. 16, 2019, p. 20518-20527.

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@article{78c5d99fe00040d6b0073ee8d7b032c4,
title = "Computational investigation of porosity effects on fracture behavior of thermal barrier coatings",
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.",
keywords = "Cohesive elements, Concurrent multiscale model, Fracture, Porosity, Thermal barrier coatings",
author = "Jayaprakash Krishnasamy and Ponnusami, {Sathiskumar A.} and Sergio Turteltaub and {van der Zwaag}, Sybrand",
year = "2019",
doi = "10.1016/j.ceramint.2019.07.031",
language = "English",
volume = "45",
pages = "20518--20527",
journal = "Ceramics International",
issn = "0272-8842",
publisher = "Elsevier",
number = "16",

}

RIS

TY - JOUR

T1 - Computational investigation of porosity effects on fracture behavior of thermal barrier coatings

AU - Krishnasamy, Jayaprakash

AU - Ponnusami, Sathiskumar A.

AU - Turteltaub, Sergio

AU - van der Zwaag, Sybrand

PY - 2019

Y1 - 2019

N2 - 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.

AB - 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.

KW - Cohesive elements

KW - Concurrent multiscale model

KW - Fracture

KW - Porosity

KW - Thermal barrier coatings

UR - http://www.scopus.com/inward/record.url?scp=85068464939&partnerID=8YFLogxK

U2 - 10.1016/j.ceramint.2019.07.031

DO - 10.1016/j.ceramint.2019.07.031

M3 - Article

VL - 45

SP - 20518

EP - 20527

JO - Ceramics International

T2 - Ceramics International

JF - Ceramics International

SN - 0272-8842

IS - 16

ER -

ID: 55204895