Fracture Toughness Testing Using Non-Standard PCVN Specimens: Experiments and Specimen Geometry Effects on T0 Reference Temperature

2018 ◽  
Author(s):  
Vitor Scarabeli Barbosa ◽  
Claudio Ruggieri
Keyword(s):  
Fracture Toughness ◽  
Cleavage Fracture ◽  
Master Curve ◽  
High Strength ◽  
Potential Effect ◽  
Reference Temperature ◽  
Fracture Toughness Testing ◽  
Toughness Testing ◽  
Additional Support

This work addresses an experimental investigation on the cleavage fracture behavior of a high strength, low alloy structural steel using non-standard PCVN specimens. The primary purpose is to investigate the effects of increased specimen span on experimentally measured fracture toughness values and implications for the characterization of the temperature dependence of toughness based on the Master Curve methodology. Fracture toughness testing conducted on various PCVN geometries with increased specimen span extracted from an A572 Grade 50 steel plate provides the cleavage fracture resistance data in terms of the J-integral at cleavage instability, Jc. The experimental results show a potential effect of specimen span on Jc-values which can help mitigating the effects of constraint loss often observed in smaller fracture specimens. An exploratory application to determine the reference temperature, T0, derived from the Master Curve methodology also provides additional support for using non-standard bend specimens in routine fracture applications.

Fracture Toughness Testing of a Low Alloy Structural Steel Using Non-Standard Bend Specimens and an Exploratory Application to Determine the Reference Temperature, T0

2017 ◽  
Author(s):  
Vitor Scarabeli Barbosa ◽  
Claudio Ruggieri
Keyword(s):  
Fracture Toughness ◽  
Structural Steel ◽  
Cleavage Fracture ◽  
Test Procedure ◽  
Reference Temperature ◽  
Width Ratio ◽  
Fracture Toughness Test ◽  
Fracture Toughness Testing ◽  
Loading Mode ◽  
Toughness Testing

This work addresses an experimental investigation on the cleavage fracture behavior of an ASTM A572 high strength, low alloy structural steel using standard and non-standard SE(B) specimens, including a non-standard PCVN configuration. One purpose of this study is to develop a fracture toughness test procedure applicable to bend geometries with varying specimen span over width ratio (a/W) and loaded under 3-point and 4-point flexural configuration. We provide a new set of plastic η-factors applicable to these non-standard bend geometries which serve to estimate the experimentally measured toughness values in terms of load-displacement records. Another purpose is to investigate the effects of geometry and loading mode in fracture tests using non-standard bend specimens. Fracture toughness testing conducted on various bend specimen geometries extracted from an A572 Grade 50 steel plate provides the cleavage fracture resistance data in terms of the J-integral at cleavage instability, Jc. The experimental results show a potential effect of specimen geometry and loading mode on Jc-values which can help mitigating the effects of constraint loss often observed in smaller fracture specimens. An exploratory application to determine the reference temperature, T0, derived from the Master Curve methodology also provides additional support for using non-standard bend specimens in routine fracture applications.

scholarly journals Master Curve Fracture Toughness Characterization of Eurofer97 Steel Variants Using Miniature Multi-Notch Bend Bar Specimens for Fusion Applications

2019 ◽  
Author(s):  
Xiang Chen ◽  
Mikhail A. Sokolov ◽  
Arunodaya Bhattacharya ◽  
Logan N. Clowers ◽  
Tim Graening ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Master Curve ◽  
Cumulative Probability ◽  
Fracture Toughness Testing ◽  
Master Curve Method ◽  
Fusion Applications ◽  
Curve Method ◽  
Toughness Testing ◽  
Reasonable Prediction

Abstract In this study, we performed fracture toughness testing of ten Eurofer97 steel variants using precracked miniature multi-notch bend bar (M4CVN) specimens based on the Master Curve method in the ASTM E1921 standard. Additional Vickers microhardness and room temperature tensile testing complemented the fracture toughness testing. Compared with standard Eurofer97, the ten variants didn’t show a comprehensive improvement of mechanical properties. The Master Curve method was found to yield a reasonable prediction of fracture toughness results obtained from M4CVN specimens with most valid fracture toughness data within the 2% and 98% tolerance boundaries of the Master Curve. The three-parameter Weibull distribution with Weibull exponent b = 4 also yielded excellent prediction of the relationship between fracture toughness results KJc and the cumulative probability for failure pf for one steel variant.

A Micromechanics Approach for Assessing the Applicability of Precracked Charpy Specimens to Determine the T0 Reference Temperature

2013 ◽  
Author(s):  
Rafael G. Savioli ◽  
Claudio Ruggieri
Keyword(s):  
Fracture Toughness ◽  
Cleavage Fracture ◽  
Pressure Vessel ◽  
Reference Temperature ◽  
Pressure Vessel Steel ◽  
Vessel Steel ◽  
Toughness Testing ◽  
The Relationship ◽  
Resistance Data ◽  
Weibull Stress

This work describes an application of a micromechanics model for cleavage fracture to determine the reference temperature for pressure vessel steels from precracked Charpy (PCVN) specimens. A central objective is evaluate the effectiveness of the Weibull stress (σw) model to correct effects of constraint loss in PCVN specimens which serve to determine the indexing temperature T0 based on the Master Curve methodology. Fracture toughness testing conducted on an A285 Grade C pressure vessel steel provides the cleavage fracture resistance data needed to estimate T0. Very detailed non-linear finite element analyses for 3-D models of plane-sided SE(B) and PCVN specimens provide the evolution of near-tip stress field with increased macroscopic load (in terms of the J-integral) to define the relationship between σw and J from which the variation of fracture toughness across different crack configurations is predicted. For the tested material, the Weibull stress methodology yields estimates for the reference temperature, T0, from small fracture specimens which are in good agreement with the corresponding estimates derived from testing of much larger crack configurations.

scholarly journals Numerical Simulation of Fracture Toughness Testing by Prediction Model of Cleavage Fracture Toughness

2013 ◽  
Vol 99 (1) ◽  
pp. 50-59 ◽  
Author(s):  
Kazuki Shibanuma ◽  
Shuji Aihara ◽  
Motoyuki Matsubara ◽  
Hiroyuki Shirahata ◽  
Tsunehisa Handa
Keyword(s):  
Numerical Simulation ◽  
Fracture Toughness ◽  
Prediction Model ◽  
Cleavage Fracture ◽  
Fracture Toughness Testing ◽  
Toughness Testing

Fracture Toughness Testing of Pipeline Girth Welds

2004 ◽  
Author(s):  
G. Shen ◽  
J. A. Gianetto ◽  
R. Bouchard ◽  
J. T. Bowker ◽  
W. R. Tyson
Keyword(s):  
Fracture Toughness ◽  
Pipeline Steel ◽  
High Strength ◽  
X80 Pipeline Steel ◽  
Factors Affecting ◽  
Fracture Toughness Testing ◽  
Toughness Testing ◽  
Girth Welds ◽  
Guidelines And Recommendations ◽  
Testing Standards

The guidelines and recommendations for fracture toughness testing of pipeline girth welds outlined in CSA Z662-03, Annex K are reviewed in this work. In Annex K of CSA Z662-03, the specimen type and notch location have been grouped into four categories and the CTOD tests are to be carried out in accordance with either BSI Standard 7448 or ASTM Standard E 1290. In the present study, CTOD tests have been conducted on a manual shielded-metal-arc weld (SMAW) that was prepared in a high strength X80 pipeline steel. The experimental results obtained by applying the two testing standards are compared. The focus was to identify the differences between these two standards that may significantly affect the test results, such as the requirements for straightness of the fatigue crack, and the equations and parameters used for evaluation of CTOD. Some additional factors affecting the testing, such as selection of test specimen location and procedures for targeting specific weldment microstructures as well as the application of local compression, are also discussed. The variation of strength and toughness with clock position around the circumference of the girth welds has also been studied.

scholarly journals Guidelines for IAEA Small Specimen Test Techniques Master Curve Fracture Toughness Testing

2020 ◽  
Author(s):  
Xiang Chen ◽  
Rebeca Hernandez Pascual ◽  
Marta Serrano ◽  
David Andres ◽  
Henk Nolles ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Master Curve ◽  
Small Specimen ◽  
Fracture Toughness Testing ◽  
Specimen Test ◽  
Toughness Testing ◽  
Curve Fracture
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