PSI - Issue 42

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2019) 000 – 000 Available online at www.sciencedirect.com ScienceDirect

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 42 (2022) 1145–1152

© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the 23 European Conference on Fracture – ECF23 Abstract The problem of thermal fracture of functionally graded thermal barrier coatings (FGCs) on a homogeneous substrate under the influence of thermo-mechanical loadings is studied in the presented work. It is assumed that FGCs contain a pre-existing system of multiple cracks, edge and/or internal. The method of analytical functions of complex variables and singular integral equations, as well as a mechanical quadrature method for solving singular integral equations were used. The functional graded material properties (including the fracture toughness) are modelled by the formulas based on the rule of mixtures (RoM) with a power-law coefficient λ as the grading parameter. The following fracture characteristics are calculated: stress intensity factors, critical stresses and fracture angles. A series of computational experiments is carried out for FGC/H structures with typical systems of multiple cracks in the FGC at different grading parameters. As illustrative examples, systems of edge cracks and edge cracks with internal cracks are investigated. The results show that the grading parameter λ has a dominant effect on the fracture characteristics. The presented model allows to correlate the material parameters, geometrical parameters and the main fracture characteristics, which can be the basis for the solution for an optimization problem, e.g. to find the grading parameter λ and the crack arrangements that increase the fracture toughness. © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23 Keywords: Functionally graded coating; fracture resistance; thermo-mechanical load ublished by Elsevier B.V. 23 European Conference on Fracture - ECF23 Thermal fracture resistance of functionally graded thermal barrier coatings with systems of multiple cracks. Application of rule of mixtures. Vera Petrova* a , Siegfried Schmauder a a Institute for Materials Testing, Materials Science and Strength of Materials (IMWF), University of Stuttgart, Pfaffenwaldring 32, 70569 Stuttgart, Germany a a

* Corresponding author. Tel.: +49-711-685-63339; fax:+49-711-685-67779. E-mail address: vera.petrova@imwf.uni-stuttgart.de;veraep@gmail.com

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23

2452-3216 © 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the 23 European Conference on Fracture – ECF23 10.1016/j.prostr.2022.12.146