Prediction of interface failure probability in bi-material ceramic joints [Elektronische Ressource] / Iryna Melikayeva. Betreuer: O. Kraft

PREDICTION OF INTERFACE FAILURE PROBABILITY IN BI-MATERIAL CERAMIC JOINTS Zur Erlangung des akademischen Grades Doktor der Ingenieurwissenschaften der Fakultät für Maschinenbau Karlsruher Institut für Technologie (KIT) genehmigte Dissertation von M.Sc. Iryna Melikayeva geboren am 13.11.1985 in Dnipropetrowsk, Ukraine Tag der mündlichen Prüfung: 30.05.2011 Hauptreferent: Prof. Dr. rer. nat. Oliver Kraft Korreferent: Prof. Dr. Volodymyr Loboda Abstract Bi-material ceramic joints are used in a number of engineering structures to enhance the functionality and lifetime of technological components. On the other hand, delamination of material composites, caused by the growth of natural flaws at material interfaces, can lead to catastrophic failure of the whole component and loss of the components functionality. Since interface failure of brittle composites is determined by the scatter of interface flaws, the reliability must be evaluated based on probabilistic methods such as the Weibull theory. In the present work, the Weakest Link approach will be generalized for the case of bi-material ceramic joints in order to extend the probabilistic model available for homogeneous materials. Here, a fracture mechanics model is developed to obtain a failure criterion for interface cracks. It is shown that the interface failure probability becomes a function of the crack tip mode-mixity state.