Modelling the fracture behaviour of thermal barrier coatings containing healing particles

Modelling the fracture behaviour of thermal barrier coatings containing healing particles

Krishnasamy, J. (TU Delft Aerospace Structures & Computational Mechanics)
Ponnusami, Sathiskumar A. (University of Oxford)
Turteltaub, S.R. (TU Delft Aerospace Structures & Computational Mechanics)
van der Zwaag, S. (TU Delft Novel Aerospace Materials)

2018-11-05

The performance of a self-healing Thermal Barrier Coating (TBC) containing dispersed healing particles depends crucially on the mismatch in thermomechanical properties between the healing particles and the TBC matrix. The present work systematically investigates this phenomenon based on numerical simulations using cohesive element-based finite element analysis. The effect of the mismatch in Coefficient of Thermal Expansion (CTE) and fracture strength between the healing particles and the matrix on the fracture characteristics is quantified in detail. Unit cell-based analyses are conducted on a representative self-healing TBC system under a thermal loading step typically experienced by TBC systems in jet turbines. Two different simulation setups are considered within the TBC unit cell namely (i) a single pair of healing particles and (ii) a randomly distributed array of healing particles. The results of the simulations are reported in terms of the fracture pattern, crack initiation temperature and crack length for various CTE mismatch ratios. Correlations are established between the results obtained from the two simulation setups essentially revealing the effect of spatial distribution and proximity of healing particles on the fracture pattern. The results obtained from the analyses can be utilised to achieve a robust design of a self-healing TBC system.

Cohesive elements
Fracture mechanics
Healing particles
Thermal barrier coatings
Thermal mismatch

http://resolver.tudelft.nl/uuid:e63f68a9-8e3f-4ca9-b3ba-abf6a078b77f

https://doi.org/10.1016/j.matdes.2018.07.026

2019-02-01

0264-1275

Materials & Design, 157, 75-86

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.

Institutional Repository

journal article

© 2018 J. Krishnasamy, Sathiskumar A. Ponnusami, S.R. Turteltaub, S. van der Zwaag