Structural Engineering and Mechanics

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On elastic and plastic length scales in strain gradient plasticity

  • Liu, Jinxing (Faculty of Civil Engineering and Mechanics, Jiangsu University) ;
  • Wang, Wen (Faculty of Civil Engineering and Mechanics, Jiangsu University) ;
  • Zhao, Ziyu (Faculty of Civil Engineering and Mechanics, Jiangsu University) ;
  • Soh, Ai Kah (School of Engineering, Monash University Malaysia)
  • Received : 2016.06.09
  • Accepted : 2016.11.11
  • Published : 2017.01.25
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Abstract

The Fleck-Hutchinson theory on strain gradient plasticity (SGP), proposed in Adv. Appl Mech 33 (1997) 295, has recently been reformulated by adopting the strategy of decomposing the second order strain presented by Lam et al. in J Mech Pays Solids 51 (2003) 1477. The newly built SGP satisfies the non negativity of plastic dissipation, which is still an outstanding issue in other SGP theories. Furthermore, it explicitly shows how elastic strain gradients and corresponding elastic characteristic length scales come into play in general elastic-plastic loading histories. In this study, the relation between elastic length scales and plastic length scales is investigated by taking wire torsion as an example. It is concluded that the size effects arising when two sets of length scales are of the same order are essentially elastic instead of plastic.

Keywords

Acknowledgement

Supported by : National Science Foundation of China, FRGS

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