Festigkeitskennwerte für die sicherheitstechnische Auslegung keramischer Komponenten von Energieerzeugungsanlagen
Festigkeitskennwerte für die sicherheitstechnische Auslegung keramischer Komponenten von Energieerzeugungsanlagen
Failure of ceramics and other brittle materials is a volumetric damage process. In highly stressed regions of microstructural heterogeneities or design notches microcracks are evaluated. In many ceramics microcrack nuclei are the potential micromechanical energy release rates induced by internal str...
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Personal Name(s): | Buresch, F. E. |
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Meyer, Wolfgang | |
Contributing Institute: |
Publikationen vor 2000; PRE-2000; Retrocat |
Imprint: |
Jülich
Kernforschungsanlage Jülich GmbH, Zentralbiliothek, Verlag
1986
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Physical Description: |
106 p. |
Document Type: |
Report Book |
Research Program: |
ohne Topic |
Series Title: |
Berichte der Kernforschungsanlage Jülich
2102 |
Link: |
OpenAccess |
Publikationsportal JuSER |
Failure of ceramics and other brittle materials is a volumetric damage process. In highly stressed regions of microstructural heterogeneities or design notches microcracks are evaluated. In many ceramics microcrack nuclei are the potential micromechanical energy release rates induced by internal stresses. Their parameters are strongly affected by the density of the material. It was found experimentally that small density fluctuations cause multimodal strength distributions which are related to changes of fracture mechanisms. The continuum-mechanics approach to a strength distribution with the unimodal Weibull distribution function assumes one type of statistically distributed flaws in a homogeneous and isotropic material. Thus groups of specimens with different microstructures show a multimodal strength distribution. Following earlier works multimodal strength distributions are separated in unimodal Weibull distributions using physical and statistical methods. Each separated Weibull distribution characterizes a specific material variation with a specific microstructure. Within each material variation bend and tensile strength data can be converted intoone another with respect to the stress volume integral. Lifetime predictions hold only for a specific microstructure, that means the specimens and the components have identical microstructures. Contaminated data are characterized physically as well as statistically. The experimental work was exemplified with commercial high temperature ceramics of the mullite and silica type. |