Shape optimization of ceramic components using a failure probability based on extended multiaxial Weibull theory

2016 ◽  
Vol 42 (7) ◽  
pp. 8360-8375 ◽  
Author(s):  
G. Rauchs
Keyword(s):  
Shape Optimization ◽  
Failure Probability ◽  
Ceramic Components ◽  
Weibull Theory

Assessment of Notches in Ceramic Components

1995 ◽  
Vol 117 (3) ◽  
pp. 413-416 ◽  
Author(s):  
A. Bru¨ckner-Foit ◽  
A. Heger ◽  
D. Munz
Keyword(s):  
Stress Concentration ◽  
Failure Probability ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Notch Root ◽  
Stress Gradient ◽  
Ceramic Components ◽  
Weibull Theory

The failure probability of notched tensile bars is calculated using the multi-axial Weibull theory. The influence exerted by the stress concentration factor, the stress gradient in the notch root, and the Weibull exponent is analyzed.

scholarly journals Assessment of Notches in Ceramic Components

1994 ◽  
Author(s):  
A. Brückner-Foit ◽  
A. Heger ◽  
D. Munz
Keyword(s):  
Stress Concentration ◽  
Failure Probability ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Notch Root ◽  
Stress Gradient ◽  
Ceramic Components ◽  
Weibull Theory

The failure probability of notched tensile bars is calculated using the multiaxial Weibull theory. The influence exerted by the stress concentration factor, the stress gradient in the notch root, and the Weibull exponent is analysed.

Effect of Proof Testing on the Failure Probability of Multiaxially Loaded Ceramic Components

2009 ◽  
pp. 346-346-14 ◽  
Author(s):  
A Brückner-Foit ◽  
A Heger ◽  
D Munz
Keyword(s):  
Failure Probability ◽  
Proof Testing ◽  
Ceramic Components

scholarly journals Gradient based biobjective shape optimization to improve reliability and cost of ceramic components

2019 ◽  
Vol 21 (4) ◽  
pp. 1359-1387
Author(s):  
O. T. Doganay ◽  
H. Gottschalk ◽  
C. Hahn ◽  
K. Klamroth ◽  
J. Schultes ◽  
...  
Keyword(s):  
Shape Optimization ◽  
Ceramic Components ◽  
Gradient Based ◽  
Improve Reliability

Testing of a Low Cooled Ceramic Nozzle Vane Under Transient Conditions

1998 ◽  
Author(s):  
M. Dilzer ◽  
Ch. Gutmann ◽  
A. Schulz ◽  
S. Wittig
Keyword(s):  
Finite Element ◽  
Failure Probability ◽  
Operating Conditions ◽  
Finite Element Analyses ◽  
Insulating Layer ◽  
Ceramic Structure ◽  
Thermally Induced ◽  
Nozzle Vane ◽  
Ceramic Components ◽  
Sintered Silicon

At the Institut für Thermische Strömungsrnaschinen, University of Karlsruhe (ITS) a design technology has been introduced to reduce the mechanically and especially the thermally induced stresses in ceramic components. The concept is based on a three-layered construction (outer ceramic shell - heat insulating layer - metallic core) and an optimization of the thicknesses of the single layers, in order to obtain a homogenous temperature distribution in the ceramic structure. The optimization is performed by finite element analyses in combination with failure probability calculations. This methodology has been applied to increase the reliability of a first stage Sintered Silicon Carbide (SSiC) ceramic nozzle vane of a stationary gas turbine (70MW/1400°C). As a result it was found that the mechanically and thermally induced loads have been reduced considerably and do not exceed 100MPa, thus achieving adequate life based upon failure probability calculations. Even in a trip situation (fuel cutoff), when the highest loads do occur, the calculations demonstrate a significantly reduced failure probability. The results of the finite element analyses were verified by simulating the typical operating conditions after fuel cutoff in a test rig.

Numerical Shape Optimization to Decrease Failure Probability of Ceramic Structures

PAMM ◽  
2018 ◽  
Vol 18 (1) ◽  
Author(s):  
Matthias Bolten ◽  
Hanno Gottschalk ◽  
Camilla Hahn
Keyword(s):  
Shape Optimization ◽  
Failure Probability

Numerical shape optimization to decrease failure probability of ceramic structures

2019 ◽  
Vol 21 (1-6) ◽  
pp. 1-10 ◽  
Author(s):  
Matthias Bolten ◽  
Hanno Gottschalk ◽  
Camilla Hahn ◽  
Mohamed Saadi
Keyword(s):  
Shape Optimization ◽  
Failure Probability

Testing of a Low Cooled Ceramic Nozzle Vane Under Transient Conditions

1999 ◽  
Vol 121 (2) ◽  
pp. 254-258 ◽  
Author(s):  
M. Dilzer ◽  
C. Gutmann ◽  
A. Schulz ◽  
S. Wittig
Keyword(s):  
Finite Element ◽  
Failure Probability ◽  
Operating Conditions ◽  
Finite Element Analyses ◽  
Insulating Layer ◽  
Ceramic Structure ◽  
Thermally Induced ◽  
Nozzle Vane ◽  
Ceramic Components ◽  
Sintered Silicon

At the Institut fu¨r Thermische Stro¨mungsmaschinen, University of Karlsruhe (ITS), a design technology has been introduced to reduce the mechanically and especially the thermally induced stresses in ceramic components. The concept is based on a three-layered construction (outer ceramic shell, heat insulating layer, and metallic core) and an optimization of the thicknesses of the single layers, in order to obtain a homogenous temperature distribution in the ceramic structure. The optimization is performed by finite element analyses in combination with failure probability calculations. This methodology has been applied to increase the reliability of a first stage Sintered Silicon Carbide (SSiC) ceramic nozzle vane of a stationary gas turbine (70 MW/1400°C). As a result it was found that the mechanically and thermally induced loads have been reduced considerably and do not exceed 100 MPa, thus achieving adequate life based upon failure probability calculations. Even in a trip situation (fuel cutoff), when the highest loads do occur, the calculations demonstrate a significantly reduced failure probability. The results of the finite element analyses were verified by simulating the typical operating conditions after fuel cutoff in a test rig.

Time-Dependent Reliability of Ceramic Components Subjected to High-Temperature Loading in a Corrosive Environment

1999 ◽  
Author(s):  
A. Brückner-Foit ◽  
C. Ziegler
Keyword(s):  
High Temperature ◽  
Combustion Chamber ◽  
High Temperatures ◽  
Surface Oxidation ◽  
Time Dependent ◽  
Corrosive Environment ◽  
Ceramic Components ◽  
Weibull Theory ◽  
Ceramic Lining ◽  
Failure Probabilities

The time-dependent reliability of ceramic components subjected to high temperature loading can be analysed using multiaxial Weibull theory and its generalisations. In this approach it is assumed that no additional flaws are initiated during exposure to high temperatures. However, this may not be true in a highly corrosive environment such as in a combustion chamber. Additional flaws can be generated by surface oxidation, volume damage or by formation of circular pits on the surface of the component. These cases are considered in this paper. The relations for the failure probabilities are derived starting from classical Weibull theory. A fastener bolt for the ceramic lining of a combustion chamber is considered as an example.

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