J-R Curve Determination for Disk-shaped Compact Specimens Based on the Normalization Method and Direct Current Potential Drop Technique

Chen, Xiang; Nanstad, Randy K; Sokolov, Mikhail A

Title: J-R Curve Determination for Disk-shaped Compact Specimens Based on the Normalization Method and Direct Current Potential Drop Technique

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Abstract

Material ductile fracture toughness can be described by J-integral versus crack extension relationship (J-R curve). As a conventional J-R curve measurement method, unloading compliance (UC) becomes impractical in elevated temperature testing due to relaxation of the material and a friction induced back-up shape of the J-R curve. In addition, the UC method may underpredict the crack extension for standard disk-shaped compact (DC(T)) specimens. In order to address these issues, the normalization method and direct current potential drop (DCPD) technique were applied for determining J-R curves at 24 C and 500 C for 0.18T DC(T) specimens made from type 316L stainless steel. For comparison purchase, the UC method was also applied in 24 C tests. The normalization method was able to yield valid J-R curves in all tests. The J-R curves from the DCPD technique need adjustment to account for the potential drop induced by plastic deformation, crack blunting, etc. and after applying a newly-developed DCPD adjustment procedure, the post-adjusted DCPD J-R curves essentially matched J-R curves from the normalization method. In contrast, the UC method underpredicted the crack extension in all tests resulting in substantial deviation in the derived J-R curves manifested by high Jq values than the normalization ormore »« less

Authors:

Chen, Xiang ^[1]; Nanstad, Randy K ^[1]; Sokolov, Mikhail A ^[1]

ORNL

Publication Date:: Wed Jan 01 00:00:00 EST 2014

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:: Work for Others (WFO); USDOE Office of Science (SC)

OSTI Identifier:: 1224741

DOE Contract Number:: AC05-00OR22725

Resource Type:: Conference

Resource Relation:: Conference: ASTM Sixth International Symposium on Small Specimen Test Techniques, Houston, TX, USA, 20140129, 20140131

Country of Publication:: United States

Language:: English

Subject:: Fracture Toughness; J-R curve; Elastic Unloading Compliance; Normalization; DCPD

Citation Formats


                    Chen, Xiang, Nanstad, Randy K, and Sokolov, Mikhail A. J-R Curve Determination for Disk-shaped Compact Specimens Based on the Normalization Method and Direct Current Potential Drop Technique.  United States: N. p., 2014. 
        Web.

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                    Chen, Xiang, Nanstad, Randy K, & Sokolov, Mikhail A. J-R Curve Determination for Disk-shaped Compact Specimens Based on the Normalization Method and Direct Current Potential Drop Technique.  United States.

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                    Chen, Xiang, Nanstad, Randy K, and Sokolov, Mikhail A. 2014.  
        "J-R Curve Determination for Disk-shaped Compact Specimens Based on the Normalization Method and Direct Current Potential Drop Technique".  United States.  https://www.osti.gov/servlets/purl/1224741.

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@article{osti_1224741,

  title        = {J-R Curve Determination for Disk-shaped Compact Specimens Based on the Normalization Method and Direct Current Potential Drop Technique},

  author       = {Chen, Xiang and Nanstad, Randy K and Sokolov, Mikhail A},

  abstractNote = {Material ductile fracture toughness can be described by J-integral versus crack extension relationship (J-R curve). As a conventional J-R curve measurement method, unloading compliance (UC) becomes impractical in elevated temperature testing due to relaxation of the material and a friction induced back-up shape of the J-R curve. In addition, the UC method may underpredict the crack extension for standard disk-shaped compact (DC(T)) specimens. In order to address these issues, the normalization method and direct current potential drop (DCPD) technique were applied for determining J-R curves at 24 C and 500 C for 0.18T DC(T) specimens made from type 316L stainless steel. For comparison purchase, the UC method was also applied in 24 C tests. The normalization method was able to yield valid J-R curves in all tests. The J-R curves from the DCPD technique need adjustment to account for the potential drop induced by plastic deformation, crack blunting, etc. and after applying a newly-developed DCPD adjustment procedure, the post-adjusted DCPD J-R curves essentially matched J-R curves from the normalization method. In contrast, the UC method underpredicted the crack extension in all tests resulting in substantial deviation in the derived J-R curves manifested by high Jq values than the normalization or DCPD method. Only for tests where the UC method underpredicted the crack extension by a very small value, J-R curves determined by the UC method were similar to those determined by the normalization or DCPD method.},

  doi          = {},

  url          = {https://www.osti.gov/biblio/1224741},
  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {Wed Jan 01 00:00:00 EST 2014},

  month        = {Wed Jan 01 00:00:00 EST 2014}

}

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