Electrically Nonlinear Fracture Analysis of Piezoelectric Materials Based on CED (Crack Energy Density)

2007 ◽  
Vol 353-358 ◽  
pp. 1513-1516
Author(s):  
Rong Feng Liu ◽  
Byeung Gun Nam ◽  
Katsuhiko Watanabe
Keyword(s):  
Energy Density ◽  
Constitutive Model ◽  
Piezoelectric Materials ◽  
Compact Tension ◽  
Fracture Analysis ◽  
Compact Tension Specimen ◽  
Fracture Parameter ◽  
Tension Specimen ◽  
Nonlinear Constitutive Model ◽  
Nonlinear Fracture

An electrical nonlinear constitutive model for piezoelectric material is studied in this paper. Electric yielding criterion and yielding effect on CED are investigated. Using the mechanical part of CED as a fracture parameter, it is shown that the predicted fracture loads through FEA for compact tension specimen is in accordance with corresponding experimental results.

Influence of Sulfur Content on the Fracture Toughness Properties of 2 1/4 Percent Cr-1 Percent Mo Steel

1976 ◽  
Vol 98 (2) ◽  
pp. 135-142 ◽  
Author(s):  
J. F. Copeland
Keyword(s):  
Fracture Toughness ◽  
Sulfur Content ◽  
Detrimental Effect ◽  
Crack Opening ◽  
Analytical Techniques ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
Tension Specimen ◽  
Microvoid Coalescence ◽  
Opening Displacement

The effects of sulfur content on the fracture toughness properties of 2 1/4Cr-1 Mo steel were evaluated at test temperatures above, at, and below the nil ductility transition temperature (NDTT) of −23°C (−10°F). Small, 12.7-mm (0.5-in.) thick compact tension specimen results were combined with J-integral, Equivalent Energy, and Crack Opening Displacement analytical techniques to provide KIc results up to 22°C (72°F). It was found that the sulfur content of this steel has a large detrimental effect on KIc at the NDTT and above, where microvoid coalescence is the fracture mode. Sulfur has no significant effect at −73°C (−100°F) where cleavage occurs. These results also indicate that the higher Charpy V-notch energy at NDTT, shown by lower sulfur steels, is translatable into increased fracture resistance.

scholarly journals A study on the matching of constraint between steam turbine blade and laboratory specimens

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402092200
Author(s):  
Jie Yang ◽  
Yuman Liu ◽  
Haofeng Chen
Keyword(s):  
Steam Turbine ◽  
Turbine Blade ◽  
Tensile Specimen ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
Bend Specimen ◽  
Single Edge ◽  
Tension Specimen ◽  
Steam Turbine Blade ◽  
C 50

The matching of constraint between laboratory specimens and actual cracked structures is a key problem of the accurate structure integrity assessment. Different laboratory specimens and the steam turbine blade with different constraints were selected, the matching of constraint between steam turbine blade and laboratory specimens was investigated. The results shown that the steam turbine blade with 2 c = 50 mm, a/2 c = 0.20 has a matching constraint with single edge-notched bend specimen with a/ W = 0.6 and single edge-notched tensile specimen with a/ W = 0.3. The steam turbine blade with 2 c = 50 mm, a/2 c = 0.25 has a matching constraint with single edge-notched bend specimen with a/ W = 0.7. The steam turbine blade with 2 c = 50 mm, a/2 c = 0.30 has a matching constraint with single edge-notched bend specimen with a/ W = 0.5 and single edge-notched tensile specimen with a/ W = 0.1. The steam turbine blade with 2 c = 50 mm, a/2 c = 0.35 has a matching constraint with single edge-notched bend specimen with a/ W = 0.4, compact tension specimen with a/ W = 0.3 and central-cracked tension specimen with a/ W = 0.7. The steam turbine blade with a = 15 mm, a/2 c = 0.30 has a matching constraint with compact tension specimen with a/ W = 0.7 and single edge-notched tensile specimen with a/ W = 0.5. The steam turbine blade with a = 15 mm, a/2 c = 0.40 has a matching constraint with compact tension specimen with a/ W = 0.4. The steam turbine blade with a = 15 mm, a/2 c = 0.50 has a matching constraint with single edge-notched bend specimen with a/ W = 0.5.

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