| People | Locations | Statistics |
|---|---|---|
| Naji, M. |
| |
| Motta, Antonella |
| |
| Aletan, Dirar |
| |
| Mohamed, Tarek |
| |
| Ertürk, Emre |
| |
| Taccardi, Nicola |
| |
| Kononenko, Denys |
| |
| Petrov, R. H. | Madrid |
|
| Alshaaer, Mazen | Brussels |
|
| Bih, L. |
| |
| Casati, R. |
| |
| Muller, Hermance |
| |
| Kočí, Jan | Prague |
|
| Šuljagić, Marija |
| |
| Kalteremidou, Kalliopi-Artemi | Brussels |
|
| Azam, Siraj |
| |
| Ospanova, Alyiya |
| |
| Blanpain, Bart |
| |
| Ali, M. A. |
| |
| Popa, V. |
| |
| Rančić, M. |
| |
| Ollier, Nadège |
| |
| Azevedo, Nuno Monteiro |
| |
| Landes, Michael |
| |
| Rignanese, Gian-Marco |
|
Jelitto, Hans
Hamburg University of Technology
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (32/32 displayed)
- 2024Impact of thermal shock on the R-curve and subcritical damage behaviour of flame-sprayed alumina compounds
- 2023On the fracture behaviour of niobium–alumina castablescitations
- 2020Crack propagation behaviour of carbon free and carbon bonded alumina based filter materialscitations
- 2020Strong Macroscale Supercrystalline Structures by 3D Printing Combined with Self‐Assembly of Ceramic Functionalized Nanoparticlescitations
- 2020Strong Macroscale Supercrystalline Structures by 3D Printing Combined with Self‐Assembly of Ceramic Functionalized Nanoparticlescitations
- 2020Extended cubic fracture model for porous materials and the dependence of the fracture toughness on the pore sizecitations
- 2019Stable crack propagation in free standing thermal sprayed Al2O3 and Al2O3ZrO2TiO2 coatingscitations
- 2019Stable crack propagation in free standing thermal sprayed Al 2 O 3 and Al 2 O 3 —ZrO 2 —TiO 2 coatingscitations
- 2019Room temperature R-curve and stable crack growth behaviour of ZrB2–SiC ceramic compositescitations
- 2018Comparative study of static and cyclic fatigue of ZrB2-SiC ceramic compositescitations
- 2018R-curve behavior and flexural strength of zirconia-toughened alumina and partially stabilized zirconia composite laminatescitations
- 2015Nanoporous-gold-based composites: toward tensile ductilitycitations
- 2015Intergranular Nanostructure Effects on Strength and Toughness of Si3 N4citations
- 2015Tough Alumina/Polymer Layered Composites with High Ceramic Contentcitations
- 2015Nanoporous-gold-based composites : toward tensile ductility
- 2014Fracture toughness and corrosion behaviour of infiltrated Al2O3|P – Steel compositescitations
- 2013Effective permittivity of air-filled cracks in piezoelectric ceramics due to crack bridgingcitations
- 2013Automated Control of Stable Crack Growth for R-Curve Measurements in Brittle Materialscitations
- 2012Experimental Crack Front Investigation of Unpoled Soft Lead Zirconate Titanate (PZT) Using the Single Edge V-Notched Beam (SEVNB) Methodcitations
- 2011What Do We Know About Surface Charges on Cracks in Ferroelectric Ceramics?citations
- 2010What do we know about surface charges on cracks in ferroelectric ceramics?
- 2010R-Curves from Compliance and Optical Crack-Length Measurementscitations
- 2009Bridging stresses from R-curves of silicon nitridescitations
- 2009Interfacial fracture of piezoelectric multilayer actuators under mechanical and electrical loadingcitations
- 2009Determination of the crack-tip toughness in silicon nitride ceramicscitations
- 2008Fracture criterion for a conducting crack in poled PZT-PIC 151 investigated by stable crack growthcitations
- 2008R-Curve Determination for the Initial Stage of Crack Extension in Si3N4citations
- 2007Fracture in Piezoelectric Ceramics and PZT/Electrode Interfaces
- 2007Stable crack growth in piezoelectric ceramics and PZT/electrode interfaces
- 2007Structural micro-layered ceramics with surfaces under tension and compression with increasing apparent fracture toughnesscitations
- 2005Zur Bestimmung bruchmechanischer Kennwerte am Piezo-Aktor
- 2004R-Curve Measurement Instrumentation – Development and Application of a Novel System for Advanced Ceramics
Places of action
| Organizations | Location | People |
|---|
article
Effective permittivity of air-filled cracks in piezoelectric ceramics due to crack bridging
Abstract
Fracture mechanical investigations of non-conducting, air-filled cracks in piezoelectric ceramics require knowledge of the electrical permeability of the crack gap. It is well known from experiments that this electrical permeability is significantly greater than the electrical permeability of an air-filled gap with smooth faces as considered in common crack models. The present paper assesses the origin of this phenomenon by investigating the effect of crack bridging on the electrical permeability of non-conducting air-filled cracks in piezoelectric ceramics. Regions of crack bridging are identified and quantified from the crack face topography of a crack in the soft PZT ceramic PIC151, which was measured by optical 3-D microscopy after total failure of the specimen. Based on a simple homogenization approach, the dielectric properties of the realistic ceramic face gap system are quantified by means of the effective permittivity of a hypothetical medium in an idealized crack with the same crack opening and smooth faces. The effective permittivity derives to a function of the crack opening, which increases with increasing crack opening at small crack openings. For PIC151, the computed maximum effective permittivity is 46 times the permittivity of air. Despite the simplifications and assumptions adopted within the proposed model, the comparison between the predicted and measured electric potential drop across an indentation crack in the PZT ceramic Vibrit1100 reveals an overall good agreement. In conclusion, the paper provides evidence that crack bridging is indeed the reason for the increased electrical permeability of such cracks.