scholarly journals A New Analytical Method of Static Fatigue Data in Brittle Materials with an Initial Crack.

1993 ◽  
Vol 42 (482) ◽  
pp. 1331-1337
Author(s):  
Taketoshi NOJIMA ◽  
Hideki KATOH
Keyword(s):  
Analytical Method ◽  
Brittle Materials ◽  
Initial Crack ◽  
Static Fatigue ◽  
Fatigue Data

A New Probabilistic Approach for Accurate Fatigue Data Analysis of Ceramic Materials

1999 ◽  
Author(s):  
Bjoern Schenk ◽  
Peggy J. Brehm ◽  
M. N. Menon ◽  
William T. Tucker ◽  
Alonso D. Peralta
Keyword(s):  
Data Analysis ◽  
Failure Modes ◽  
Probabilistic Approach ◽  
Time Dependent ◽  
Material Strength ◽  
Static Fatigue ◽  
Oak Ridge ◽  
Fatigue Data ◽  
Ceramic Components ◽  
Dependent Failure

Statistical methods for the design of ceramic components for time-dependent failure modes have been developed which can significantly enhance component reliability, reduce baseline data generation costs, and lead to more accurate estimates of slow crack growth (SCG) parameters. These methods are incorporated into the AlliedSignal Engines CERAMIC and ERICA computer codes. Use of the codes facilitates generation of material strength parameters and SCG parameters simultaneously, by pooling fast fracture data from specimens that are of different sizes, or stressed by different loading conditions, with data derived from static fatigue experiments. The codes also include approaches to calculation of confidence bounds for the Weibull and SCG parameters of censored data and for the predicted reliability of ceramic components. This paper presents a summary of this new fatigue data analysis technique and an example demonstrating the capabilities of the codes with respect to time-dependent failure modes. This work was sponsored by the U.S. Department of Energy Oak Ridge National Laboratory (DoE/ORNL) under Contract No. DE-AC05-84OR21400.

Slow Crack Growth of a Pyroceram Glass Ceramic Under Static Fatigue Loading: Commonality of Slow Crack Growth in Advanced Ceramics

2014 ◽  
Author(s):  
Sung R. Choi ◽  
D. Calvin Faucett ◽  
Brenna Skelley
Keyword(s):  
Crack Growth ◽  
Glass Ceramic ◽  
Life Prediction ◽  
Elevated Temperatures ◽  
Slow Crack Growth ◽  
Static Fatigue ◽  
Fatigue Data ◽  
Prediction Approach ◽  
Applied Stresses ◽  
Dynamic Fatigue

An extensive experimental work for Pyroceram™ 9606 glass-ceramic was conducted to determine static fatigue at ambient temperature in distilled water. This work was an extension and companion of the previous work conducted in dynamic fatigue. Four different applied stresses ranging from 120 to 170 MPa was incorporated with a total of 20–23 test specimens used at each of four applied stresses. The slow crack growth parameters n and D were found to be n = 19 and D = 45 with a coefficient of correlation of rcoef = 0.9653. The Weibull modulus of time to failure was in a range of msf = 1.6 to 1.9 with an average of msf = 1.7±0.2. A life prediction using the previously-determined dynamic fatigue data was in excellent agreement with the static fatigue data. The life prediction approach was also applied to advanced monolithic ceramics and ceramic matrix composites based on their dynamic and static fatigue data determined at elevated temperatures. All of these results indicated that a SCG mechanism governed by a power-law crack-growth formulation was operative, a commonality of slow crack growth in these materials systems.

Slow Crack Growth of a Pyroceram Glass Ceramic Under Static Fatigue Loading—Commonality of Slow Crack Growth in Advanced Ceramics

2014 ◽  
Vol 137 (3) ◽  
Author(s):  
Sung R. Choi ◽  
D. Calvin Faucett ◽  
Brenna Skelley
Keyword(s):  
Crack Growth ◽  
Glass Ceramic ◽  
Life Prediction ◽  
Elevated Temperatures ◽  
Slow Crack Growth ◽  
Static Fatigue ◽  
Fatigue Data ◽  
Prediction Approach ◽  
Applied Stresses ◽  
Dynamic Fatigue

An extensive experimental work for Pyroceram™ 9606 glass–ceramic was conducted to determine static fatigue at ambient temperature in distilled water. This work was an extension and companion of the previous work conducted in dynamic fatigue. Four different applied stresses ranging from 120 to 170 MPa was incorporated with a total of 20–23 test specimens used at each of four applied stresses. The slow crack growth (SCG) parameters n and D were found to be n = 19 and D = 45 with a coefficient of correlation of rcoef = 0.9653. The Weibull modulus of time to failure was in a range of msf = 1.6–1.9 with an average of msf = 1.7 ± 0.2. A life prediction using the previously determined dynamic fatigue data was in excellent agreement with the static fatigue data. The life prediction approach was also applied to advanced monolithic ceramics and ceramic matrix composites (CMCs) based on their dynamic and static fatigue data determined at elevated temperatures. All of these results indicated that a SCG mechanism governed by a power-law crack growth formulation was operative, a commonality of SCG in these materials systems.

Determination of Crack Velocity as a Function of Stress Intensity from Static Fatigue Data

1994 ◽  
Vol 77 (9) ◽  
pp. 2445-2449 ◽  
Author(s):  
Prabhat K. Gupta ◽  
Daryl Inniss ◽  
Charles R. Kurkjian ◽  
Darryl L. Brownlow
Keyword(s):  
Stress Intensity ◽  
Crack Velocity ◽  
Static Fatigue ◽  
Fatigue Data

A New Probabilistic Approach for Accurate Fatigue Data Analysis of Ceramic Materials

2000 ◽  
Vol 122 (4) ◽  
pp. 637-645 ◽  
Author(s):  
Bjoern Schenk ◽  
Peggy J. Brehm ◽  
M. N. Menon ◽  
William T. Tucker ◽  
Alonso D. Peralta
Keyword(s):  
Data Analysis ◽  
Failure Modes ◽  
Probabilistic Approach ◽  
Time Dependent ◽  
Material Strength ◽  
Static Fatigue ◽  
Oak Ridge ◽  
Fatigue Data ◽  
Ceramic Components ◽  
Dependent Failure

Statistical methods for the design of ceramic components for time-dependent failure modes have been developed that can significantly enhance component reliability, reduce baseline data generation costs, and lead to more accurate estimates of slow crack growth (SCG) parameters. These methods are incorporated into the Honeywell Engines & Systems CERAMIC and ERICA computer codes. Use of the codes facilitates generation of material strength parameters and SCG parameters simultaneously, by pooling fast fracture data from specimens that are of different sizes, or stressed by different loading conditions, with data derived from static fatigue experiments. The codes also include approaches to calculation of confidence bounds for the Weibull and SCG parameters of censored data and for the predicted reliability of ceramic components. This paper presents a summary of this new fatigue data analysis technique and an example demonstrating the capabilities of the codes with respect to time-dependent failure modes. This work was sponsored by the U.S. Department of Energy/Oak Ridge National Laboratory (DoE/ORNL) under Contract No. DE-AC05-84OR21400. [S0742-4795(00)02103-7]

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

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