Experimental assessment of unvalidated assumptions in classical plasticity theory.
Abstract
This report investigates the validity of several key assumptions in classical plasticity theory regarding material response to changes in the loading direction. Three metals, two rock types, and one ceramic were subjected to nonstandard loading directions, and the resulting strain response increments were displayed in Gudehus diagrams to illustrate the approximation error of classical plasticity theories. A rigorous mathematical framework for fitting classical theories to the data, thus quantifying the error, is provided. Further data analysis techniques are presented that allow testing for the effect of changes in loading direction without having to use a new sample and for inferring the yield normal and flow directions without having to measure the yield surface. Though the data are inconclusive, there is indication that classical, incrementally linear, plasticity theory may be inadequate over a certain range of loading directions. This range of loading directions also coincides with loading directions that are known to produce a physically inadmissible instability for any nonassociative plasticity model.
 Authors:

 University of Utah, Salt Lake City, UT
 Publication Date:
 Research Org.:
 Sandia National Laboratories
 Sponsoring Org.:
 USDOE
 OSTI Identifier:
 948711
 Report Number(s):
 SAND20090351
TRN: US200908%%10
 DOE Contract Number:
 AC0494AL85000
 Resource Type:
 Technical Report
 Country of Publication:
 United States
 Language:
 English
 Subject:
 36 MATERIALS SCIENCE; APPROXIMATIONS; CERAMICS; DATA ANALYSIS; INSTABILITY; PLASTICITY; STRAINS; TESTING; METALS; ROCKS; RESPONSE FUNCTIONS; PlasticityMathematical models.; Thermal loadingMathematical models.
Citation Formats
Brannon, Rebecca Moss, Burghardt, Jeffrey A, Bauer, Stephen J, and Bronowski, David R. Experimental assessment of unvalidated assumptions in classical plasticity theory.. United States: N. p., 2009.
Web. doi:10.2172/948711.
Brannon, Rebecca Moss, Burghardt, Jeffrey A, Bauer, Stephen J, & Bronowski, David R. Experimental assessment of unvalidated assumptions in classical plasticity theory.. United States. https://doi.org/10.2172/948711
Brannon, Rebecca Moss, Burghardt, Jeffrey A, Bauer, Stephen J, and Bronowski, David R. Thu .
"Experimental assessment of unvalidated assumptions in classical plasticity theory.". United States. https://doi.org/10.2172/948711. https://www.osti.gov/servlets/purl/948711.
@article{osti_948711,
title = {Experimental assessment of unvalidated assumptions in classical plasticity theory.},
author = {Brannon, Rebecca Moss and Burghardt, Jeffrey A and Bauer, Stephen J and Bronowski, David R},
abstractNote = {This report investigates the validity of several key assumptions in classical plasticity theory regarding material response to changes in the loading direction. Three metals, two rock types, and one ceramic were subjected to nonstandard loading directions, and the resulting strain response increments were displayed in Gudehus diagrams to illustrate the approximation error of classical plasticity theories. A rigorous mathematical framework for fitting classical theories to the data, thus quantifying the error, is provided. Further data analysis techniques are presented that allow testing for the effect of changes in loading direction without having to use a new sample and for inferring the yield normal and flow directions without having to measure the yield surface. Though the data are inconclusive, there is indication that classical, incrementally linear, plasticity theory may be inadequate over a certain range of loading directions. This range of loading directions also coincides with loading directions that are known to produce a physically inadmissible instability for any nonassociative plasticity model.},
doi = {10.2172/948711},
url = {https://www.osti.gov/biblio/948711},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2009},
month = {1}
}