Estimation of stepwise crack propagation in ceramic laminates with strong interfaces

Journal Title: Frattura ed Integrità Strutturale - Year 2015, Vol 9, Issue 34

Abstract

 During the last years many researchers put so much effort to design layered structures combining different materials in order to improve low fracture toughness and mechanical reliability of the ceramics. It has been proven, that an effective way is to create layered ceramics with strongly bonded interfaces. After the cooling process from the sintering temperature, due to the different coefficients of thermal expansion of individual constituents of the composite, significant internal residual stresses are developed within the layers. These stresses can change the crack behaviour. This results to the higher value of so-called apparent fracture toughness, i.e. higher resistance of the ceramic laminate to the crack propagation. The contribution deals with a description of the specific crack behaviour in the layered alumina-zirconia ceramic laminate. The main aim is to clarify crack behaviour in the compressive layer and provide computational tools for estimation of crack behaviour in the field of strong residual stresses. The crack propagation was investigated on the basis of linear elastic fracture mechanics. Fracture parameters were computed numerically and by author’s routines. Finite element models were developed in order to obtain a stress distribution in the laminate containing a crack and to simulate crack propagation. The sharp change of the crack propagation direction was estimated using Sih’s criterion based on the strain energy density factor. Estimated crack behaviour is qualitatively in a good agreement with experimental observations. Presented approach contributes to the better understanding of the toughening mechanism of ceramic laminates and can be advantageously used for design of new layered ceramic composites and for better prediction of their failure.

Authors and Affiliations

L. Náhlík, K. Štegnerová, P. Hutař

Keywords

Related Articles

 The non-proportionality of local stress paths in engineering applications

 A scalar measure, which describes the non-proportionality of local stress paths in engineering applications, is introduced. For this purpose the moment of inertia approach by Meggiolaro is modified in a way th...

 Experimental estimation of the heat energy dissipated in a volume surrounding the tip of a fatigue crack

 Fatigue crack initiation and propagation involve plastic strains that require some work to be done on the material. Most of this irreversible energy is dissipated as heat and consequently the material temperature&...

 Deformation and fatigue behaviors of carburized automotive gear steel and predictions

 The fatigue behavior of carburized components such as automotive transmission gears is very complex due to hardness and microstructure difference, residual stresses and multi-axial stress states developed bet...

 Life estimation by varying the critical plane orientation in the modified Carpinteri-Spagnoli criterion

 The modified Carpinteri-Spagnoli (C-S) criterion is a multiaxial high-cycle fatigue criterion based on the critical plane approach. According to such a criterion, the orientation of the critical plane is linked to...

 Comparison of two multiaxial fatigue models applied to dental implants

 This paper presents two multiaxial fatigue life prediction models applied to a commercial dental implant. One model is called Variable Initiation Length Model and takes into account both the crack initiation and...

Download PDF file
  • EP ID EP106599
  • DOI 10.3221/IGF-ESIS.34.12
  • Views 72
  • Downloads 0

How To Cite

L. Náhlík, K. Štegnerová, P. Hutař (2015).  Estimation of stepwise crack propagation in ceramic laminates with strong interfaces. Frattura ed Integrità Strutturale, 9(34), 116-124. https://europub.co.uk/articles/-A-106599