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Second order stress gradient plasticity with an application to thin foil bending

Assempour, A ; Sharif University of Technology | 2017

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  1. Type of Document: Article
  2. DOI: 10.1007/s10999-016-9336-3
  3. Publisher: Springer Netherlands , 2017
  4. Abstract:
  5. The continuum theory of dislocations is applied to formulate the problem of a double ended dislocation pileup under quadratic applied stress. Accordingly, a second order stress gradient plasticity model is presented to address the contribution of the first and the second stress gradients in the effect interpretation. The model is employed to predict the initial strengthening and subsequent hardening in curved and straight thin foils under pure bending within the continuum framework. It is shown that the so-called stress gradient plasticity model that ignores the second stress gradient may not give sound interpretations of the size effects. The plastic response of thin foils is affected by both the first and second stress gradients, yet their interaction strongly depends upon the length scale parameter. The larger the length scale parameter, the quadratic term contribution would be important and the predictions of the first and second order models deviate significantly from each other. © 2016, Springer Science+Business Media Dordrecht
  6. Keywords:
  7. Foil bending ; Dislocation pileup ; Stress gradient plasticity ; Continuum mechanics ; Grain size and shape ; Applied stress ; Continuum theory ; Dislocation pileups ; Length scale parameter ; Plastic response ; Second-order models ; Size effects ; Stress gradient ; Plasticity
  8. Source: International Journal of Mechanics and Materials in Design ; Volume 13, Issue 2 , 2017 , Pages 321-334 ; 15691713 (ISSN)
  9. URL: https://link.springer.com/article/10.1007/s10999-016-9336-3