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Search Publications by: Thomas H. Gnaupel-Herold (Fed)

Displaying 51 - 75 of 98

Uncertainty in Retained Austenite Measurements Applied to Individual Crystallographic Orientations

May 6, 2015

Author(s)

Adam A. Creuziger, Thomas H. Gnaeupel-Herold

A technique to measure the phase volume fraction of an individual orientation and the uncertainty in the measurement is demonstrated in this paper. The technique of complete pole figure averaging was used to assess the phase fraction of retained austenite

Measurement of Biaxial Stress Based on Elasto-Viscoplastic Self-Consistent Analysis of X-ray Diffraction

July 16, 2014

Author(s)

Youngung Jeong, Thomas H. Gnaupel-Herold, Frederic Barlat, Mark Iadicola, Adam Abel Creuziger, Myoung-Gyu Lee

Neutron Measurements of Stresses in a Test Artifact produced by Laser-based Additive Manufacturing

February 18, 2014

Author(s)

Thomas H. Gnaeupel-Herold, John A. Slotwinski, Shawn P. Moylan

A stainless steel test artifact produced by Direct Metal Laser Sintering and similar to a proposed standardized test artifact was examined using neutron diffraction. The artifact contained a number of structures with different aspect ratios pertaining to

Crystallographic Texture Evolution in 1008 Steel Sheet During Multi-Axial Tensile Strain Paths

January 7, 2014

Author(s)

Adam A. Creuziger, Lin Hu, Thomas H. Gnaeupel-Herold, Anthony D. Rollett

This paper considers the crystallographic texture evolution in a 1008 low carbon steel. The texture evolution along uniaxial, plane strain and balanced biaxial strain states were measured. For uniaxial testing, grains tend to rotate such that the {111}

Measurement of Uncertainty in Orientation Distribution Function (ODF) Calculations

October 28, 2013

Author(s)

Adam A. Creuziger, Komal Syed, Thomas H. Gnaeupel-Herold

Interpretation of Diffraction Data from In-situ Stress Measurements during Biaxial Sheet Metal Forming

September 1, 2013

Author(s)

Thomas H. Gnaupel-Herold, Mark A. Iadicola, Adam A. Creuziger, Timothy J. Foecke, Lin Hu

Biaxial yield behavior is determined in-situ through X-ray lattice strain measurements. The distributions of d-spacings in different sample directions is affected both by the changes in diffraction elastic constants (DEC) from evolving texture and by the

An Investigation of the Accuracy of Diffraction Stress Evaluation of Textured Materials

August 4, 2012

Author(s)

Thomas H. Gnaupel-Herold, Adam A. Creuziger, Mark A. Iadicola

The determination of residual or applied stress through X-ray or neutron diffraction is generally regarded as a mature method. Most x-ray diffractometers can be used to perform a measurement of lattice strain vs. tilt angle, which is then converted into

A Software for Diffraction Stress Factor Calculations for Textured Materials

June 18, 2012

Author(s)

Thomas H. Gnaeupel-Herold

A software for the calculation of diffraction elastic constants (DEC) for materials both with and without preferred orientation was developed. All grain-interaction models that can use the crystallite orientation distribution function (ODF) are

ISODEC: Software for Calculating Diffraction Elastic Constants

June 1, 2012

Author(s)

Thomas H. Gnaeupel-Herold

A program is introduced that calculates diffraction elastic constants for the models according to Reuss, Hill, Kröner and inverse Kröner. For materials with preferred orientation it uses the orientation distribution function (ODF) to calculate the

Effective X-Ray Elastic Constant Measurement for In Situ Stress Measurement of Biaxially Strained AA5754-O

May 30, 2012

Author(s)

Mark A. Iadicola, Thomas H. Gnaeupel-Herold

A method of measuring biaxial stress-strain curved for sheet metal samples subjected to large plastic strains is described for one example aluminum alloy (AA 5754-O). The method uses a prtable X-ray diffraction (XRD) system to measure in situ stresses

Neutron Diffraction Measurements for Residual Stresses in AL-6XN Stainless Steel Welded Beams

February 20, 2012

Author(s)

Xiaohua Cheng, Henry J. Prask, Thomas H. Gnaupel-Herold, Vladimir Luzin, John W. Fisher

A Model for Calculating Diffraction Elastic Constants

January 18, 2012

Author(s)

Thomas H. Gnaeupel-Herold, Adam A. Creuziger, Mark A. Iadicola

An alternate model is proposed to calculate the diffraction elastic constants from the elastic constants of the single crystal. It is based on the inverse elastic susceptibility and thus it is related to the elastic polarization approach widely known as

Evolution of Anisotropic Stress Factors with Texture in the Biaxial Deformation of HSLA50 Steel

January 3, 2012

Author(s)

Thomas H. Gnaeupel-Herold, Adam A. Creuziger, Mark A. Iadicola

The effects of crystallographic texture produced by biaxial deformation on the diffraction elastic constants (DEC) are discussed. Predictions of DEC values from established and new models of grain interactions are compared with experimental data. The