Edge Fracture Resistance of Glasses: Different Conical Indenters and the Fracture Initiation Barrier

2016 ◽  
Vol 48 (3) ◽  
pp. 365-370 ◽  
Author(s):  
G. A. Gogotsi ◽  
V. I. Galenko
Keyword(s):  
Fracture Resistance ◽  
Fracture Initiation ◽  
Edge Fracture

Evaluation of fracture resistance of ceramics: Edge fracture tests

2007 ◽  
Vol 33 (3) ◽  
pp. 315-320 ◽  
Author(s):  
George Gogotsi ◽  
Sergey Mudrik ◽  
Vasily Galenko
Keyword(s):  
Fracture Resistance ◽  
Edge Fracture ◽  
Fracture Tests

Testing Techniques for Establishing Fracture Resistance of Steel in a Sour Environment

2017 ◽  
Author(s):  
Muhammad S. Ali
Keyword(s):  
Fracture Toughness ◽  
Fracture Resistance ◽  
Crack Extension ◽  
Pipeline Steel ◽  
Fracture Initiation ◽  
Load Level ◽  
Manganese Steel ◽  
Initiation Toughness ◽  
Loading Rates ◽  
Rate Of Increase

It is well established that sour operating environments can give rise to significantly reduced fracture toughness of pipelines made of carbon manganese steel. Fracture resistance of a material is usually defined in terms of a fracture resistance curve, commonly known as an R-curve which is determined by testing pre-cracked specimens under a rising load. Fracture resistance data can be derived by the single specimen method, where crack extension is determined using unloading compliance or the multiple specimen method, where crack extension is measured from the fracture face of each specimen and each specimen is taken to a different load level. The fracture resistance behaviour of API 5L X65 grade pipeline steel determined by testing single edge notched bend specimens in a specific sour environment using both single and multiple specimen test methods is reported. The fracture resistance of the steel was found to be highly sensitive to the loading rates (described by the initial rate of increase of stress intensity factor in the elastic range) applied during the fracture resistance tests. It was possible to identify a loading rate slow enough to provide fracture initiation toughness reasonably close to the expected lower bound toughness. It is possible to produce similar R-curves from single and multiple specimen testing methods (if conditions are otherwise the same). Under comparable loading rates and environmental conditions, side grooved specimens resulted in lower fracture toughness as compared to the toughness determined from the plane sided specimens. It was also noticed that there was a weaker correlation between side grooving and toughness at slower loading rates.

scholarly journals Fracture Resistance of Ceramics: Edge Fracture Method

2005 ◽  
Vol 37 (5) ◽  
pp. 499-505 ◽  
Author(s):  
G. A. Gogotsi ◽  
V. I. Galenko ◽  
B. I. Ozerskii ◽  
T. A. Khristevich
Keyword(s):  
Fracture Resistance ◽  
Edge Fracture

scholarly journals Fracture Surface Analysis of Clinically Failed Fixed Partial Dentures

2006 ◽  
Vol 85 (3) ◽  
pp. 277-281 ◽  
Author(s):  
B. Taskonak ◽  
J.J. Mecholsky ◽  
K.J. Anusavice
Keyword(s):  
Fracture Mechanics ◽  
Fracture Surface ◽  
Crack Initiation ◽  
Surface Analysis ◽  
Fracture Resistance ◽  
Fracture Initiation ◽  
Occlusal Surface ◽  
Contact Damage ◽  
Fracture Surface Analysis

Ceramic systems have limited long-term fracture resistance, especially when they are used in posterior areas or for fixed partial dentures. The objective of this study was to determine the site of crack initiation and the causes of fracture of clinically failed ceramic fixed partial dentures. Six Empress 2® lithia-disilicate (Li2O·2SiO2)-based veneered bridges and 7 experimental lithia-disilicate-based non-veneered ceramic bridges were retrieved and analyzed. Fractography and fracture mechanics methods were used to estimate the stresses at failure in 6 bridges (50%) whose fracture initiated from the occlusal surface of the connectors. Fracture of 1 non-veneered bridge (8%) initiated within the gingival surface of the connector. Three veneered bridges fractured within the veneer layers. Failure stresses of the all-core fixed partial dentures ranged from 107 to 161 MPa. Failure stresses of the veneered fixed partial dentures ranged from 19 to 68 MPa. We conclude that fracture initiation sites are controlled primarily by contact damage.

Micromechanics Measurements Applied to Integrated Circuit Microelectronics

1997 ◽  
Vol 473 ◽  
Author(s):  
David R. Clarke
Keyword(s):  
Integrated Circuits ◽  
Integrated Circuit ◽  
Fracture Resistance ◽  
Interface Fracture ◽  
New Techniques ◽  
Fracture Properties ◽  
Engineered Structures ◽  
Mechanical And Fracture Properties ◽  
Interconnect Lines ◽  
Metallic Interconnect

ABSTRACTAs in other engineered structures, fracture occasionally occurs in integrated microelectronic circuits. Fracture can take a number of forms including voiding of metallic interconnect lines, decohesion of interfaces, and stress-induced microcracking of thin films. The characteristic feature that distinguishes such fracture phenomena from similar behaviors in other engineered structures is the length scales involved, typically micron and sub-micron. This length scale necessitates new techniques for measuring mechanical and fracture properties. In this work, we describe non-contact optical techniques for probing strains and a microscopic “decohesion” test for measuring interface fracture resistance in integrated circuits.

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