Accounting for localized deformation: a simple computation of true stress in micropillar compression experiments

Fuente: arXiv
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Main Authors: Smiri, Jalal, Salman, Oguz Umut, Ghidelli, Matteo, Ionescu, Ioan R.
Format: Preprint
Published: 2023
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author Smiri, Jalal
Salman, Oguz Umut
Ghidelli, Matteo
Ionescu, Ioan R.
author_facet Smiri, Jalal
Salman, Oguz Umut
Ghidelli, Matteo
Ionescu, Ioan R.
contents Compression experiments are widely used to study the mechanical properties of materials at micro- and nanoscale. However, the conventional engineering stress measurement method used in these experiments neglects to account for the alterations in the material's shape during loading. This can lead to inaccurate stress values and potentially misleading conclusions about the material's mechanical behavior especially in the case of localized deformation. To address this issue, we present a method for calculating true stress in cases of localized plastic deformation commonly encountered in experimental settings: (i) a single band and (ii) two bands oriented in arbitrary directions with respect to the vertical axis of the pillar (either in the same or opposite directions). Our simple analytic formulas can be applied to homogeneous and isotropic materials and crystals, requiring only standard data (displacement-force curve, aspect ratio, shear band angle and elastic strain limit) obtained from experimental results and eliminating the need for finite element computations. Our approach provides a more precise interpretation of experimental results and can serve as a valuable and simple tool in material design and characterization.
format Preprint
id arxiv_https___arxiv_org_abs_2310_06476
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Accounting for localized deformation: a simple computation of true stress in micropillar compression experiments
Smiri, Jalal
Salman, Oguz Umut
Ghidelli, Matteo
Ionescu, Ioan R.
Materials Science
Mesoscale and Nanoscale Physics
Compression experiments are widely used to study the mechanical properties of materials at micro- and nanoscale. However, the conventional engineering stress measurement method used in these experiments neglects to account for the alterations in the material's shape during loading. This can lead to inaccurate stress values and potentially misleading conclusions about the material's mechanical behavior especially in the case of localized deformation. To address this issue, we present a method for calculating true stress in cases of localized plastic deformation commonly encountered in experimental settings: (i) a single band and (ii) two bands oriented in arbitrary directions with respect to the vertical axis of the pillar (either in the same or opposite directions). Our simple analytic formulas can be applied to homogeneous and isotropic materials and crystals, requiring only standard data (displacement-force curve, aspect ratio, shear band angle and elastic strain limit) obtained from experimental results and eliminating the need for finite element computations. Our approach provides a more precise interpretation of experimental results and can serve as a valuable and simple tool in material design and characterization.
title Accounting for localized deformation: a simple computation of true stress in micropillar compression experiments
topic Materials Science
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2310.06476