scholarly journals Developing Fatigue Pre-crack Procedure to Evaluate Fracture Toughness of Pipeline Steels Using Spiral Notch Torsion Test

2012 ◽  
Author(s):  
Jy-An John Wang ◽  
Ting Tan ◽  
Hao Jiang ◽  
Wei Zhang ◽  
Zhili Feng
Keyword(s):  
Fracture Toughness ◽  
Torsion Test ◽  
Pipeline Steels ◽  
Spiral Notch

SAE 4340 Fracture Toughness Evaluation Following Wang’s Formulation for Spiral Notch Torsion Test Specimens

2021 ◽  
Vol 50 (1) ◽  
pp. 20200417
Author(s):  
Guilherme Bernardes Rodrigues ◽  
Marcelo Torres Piza Paes ◽  
Francisco Francelino Ramos Neto ◽  
Sinésio Domingues Franco ◽  
Rosenda Valdés Arencibia ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Torsion Test ◽  
Toughness Evaluation ◽  
Fracture Toughness Evaluation ◽  
Spiral Notch

Spiral Notch Torsion Test Use for Determining Fracture Toughness of Structural Materials

2012 ◽  
Author(s):  
Jy-An John Wang ◽  
Fei Ren ◽  
Ting Tan
Keyword(s):  
Fracture Toughness ◽  
Three Dimensional ◽  
Torsion Test ◽  
Computer Code ◽  
Structural Materials ◽  
Fracture Toughness Test ◽  
Materials Used ◽  
Torsion Fracture ◽  
Three Dimensional Finite Element ◽  
Spiral Notch

Spiral Notch Torsion Fracture Toughness Test (SNTT) was developed recently to measure the intrinsic fracture toughness (KIC) of structural materials. The SNTT system operates by applying pure torsion to uniform cylindrical specimens with a notch line that spirals around the specimen at a 45° pitch. The KIC values are obtained with the aid of a three-dimensional finite-element computer code, TOR3D-KIC. The SNTT method is uniquely suitable for testing a wide variety of materials used extensively in pressure vessel and piping structural components and weldments, including others such as ceramics, their composites, graphite, concrete, and polymeric composites. The SNTT test results for some of these structural materials are demonstrated in this paper.

Measurement of Fracture Toughness of Materials With Non-Uniform Microstructure Based on Spiral Notch Torsion Test

2010 ◽  
Author(s):  
Wei Zhang ◽  
Zhili Feng ◽  
Jy-An Wang
Keyword(s):  
Fracture Toughness ◽  
Axial Direction ◽  
Torsion Test ◽  
Compact Tension ◽  
Element Analysis ◽  
Heating And Cooling ◽  
Uniform Microstructure ◽  
Heat Treated ◽  
Plain Strain ◽  
Spiral Notch

Materials such as welds consist of highly non-uniform distribution of microstructure. It is typically difficult to measure fracture toughness of those materials using the conventional testing approaches such as ASTM compact tension test, since the non-uniform microstructure can induce irregular crack propagation front. In this study, the spiral notch torsion test (SNTT) is enhanced to measure the fracture toughness of welds. The test specimen resembles a round tensile bar with a spiral-shaped notch on the circumference. To introduce nonuniform microstructure, the heat treatment with a Gleeble system is used to rapidly heat and quench the specimen. The heating and cooling rates applied are typical of those experienced in welding. The hardness distribution in the axial direction of as-heat-treated specimen has a bell shape centered in the middle of the specimen. This distribution resembles that in a transverse section of a weldment. During loading, the specimen is twisted about its axis. It is possible to achieve a Mode I crack front that is long enough to meet the plain strain state and other fracture mechanics requirements for testing the local toughness of weld region. Fracture toughness calculation based on finite element analysis is performed to convert the recorded load-displacement into the fracture toughness KIc.

Using Torsion Bar Testing to Determine Fracture Toughness of Ceramic Materials

2002 ◽  
Author(s):  
J. A. Wang ◽  
K. C. Liu ◽  
G. A. Joshi
Keyword(s):  
Fracture Toughness ◽  
Crack Opening ◽  
Torsion Test ◽  
Ceramic Materials ◽  
Type Specimen ◽  
Small Region ◽  
Fracture Load ◽  
Test Method ◽  
Finite Element Program ◽  
Spiral Line

A new method, designated as Spiral Notch Torsion Test (SNoTT), is introduced for determining fracture toughness KIC of materials ranging from metallic alloys to brittle ceramics and their composites. A round-rod specimen having a V-grooved spiral line with a 45° pitch is subjected to pure torsion. This loading configuration creates a uniform tensile-stress crack-opening mode, Mode-I, with a transverse plane-strain state along the grooved line. This technique is analogous to the conventional test method using a compact-type specimen with a thickness equivalent to the full length of the spiral line. KIC values are determined from the fracture load and crack length with the aid of an in-house developed 3-D finite element program (TOR3D-KIC). A mixed mode (modes I and III) fracture toughness value can be determined by varying the pitch of the spiral line or varying the ratio of axial to torsion loads. Since the key information needed for determining KIC values is manifested within a small region near the crack tip, the specimen can be significantly miniaturized without the loss of generality. Limited results obtained for various materials are compared with published KIC values, showing differences of less than 2% in general and 6% maximum in one case. The experimental technique and theoretical basis of the proposed method are presented in detail.

The characterization of fracture toughness of two X-70 pipeline steels

1980 ◽  
Vol 2 (1) ◽  
pp. 34-50 ◽  
Author(s):  
R. Maiti ◽  
J. S. Nadeau ◽  
E. B. Hawbolt
Keyword(s):  
Fracture Toughness ◽  
Pipeline Steels

Effects of Temperature and Crack Tip Constraint on Cleavage Fracture Toughness in the Weld Thermal Simulated X80 Pipeline Steels

2011 ◽  
Vol 197-198 ◽  
pp. 1595-1598 ◽  
Author(s):  
Jie Xu ◽  
Yu Fan
Keyword(s):  
Fracture Toughness ◽  
Cleavage Fracture ◽  
Crack Tip ◽  
Coarse Grained ◽  
Material Microstructure ◽  
Element Analysis ◽  
Pipeline Steels ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Crack Tip Constraint

This paper studies the effects of temperature and crack tip constraint on cleavage fracture toughness of the weld thermal simulated X80 pipeline steels. A large number of fracture toughness (as denoted by CTOD) tests together with 3D finite element analysis are performed using single edge notched bending (SENB) and tension (SENT) specimens at different temperatures. Coarse-grained heat-affected zone (CGHAZ) is considered as the material microstructure in preparation of the weld thermal simulated fracture mechanics specimens.

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