Acta Mechanica Solida Sinica

, Volume 22, Issue 3, pp 213–225 | Cite as

Plastic zone of semi-infinite crack in planar Kagome and triangular lattices

  • Xinming Qiu
  • Lianghong He
  • Yueqiang Qian
  • Xiong Zhang


The fracture investigations of the planar lattices made of ductile cell walls are currently limited to bending-dominated hexagonal honeycomb. In this paper, the plastic zones of stretching-dominated lattices, including Kagome and triangular lattices, are estimated by analyzing their effective yield loci. The normalized in-plane yield loci of these two lattices are almost identical convex curves enclosed by 4 straight lines, which is almost independent of the relative density but is highly sensitive to the principal stress directions. Therefore, the plastic zones around the crack tip of Kagome and triangular are estimated to be quite different to those of the continuum solid and also hexagonal lattice. The plastic zones predictions by convex yield surfaces of both lattices are validated by FE calculations, although the shear lag region caused by non-local bending effect in the Kagome lattice enlarges the plastic zone in cases of small ratio of r p /l.

Key words

lattice yield surface crack tip plastic zone anisotropic 


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Copyright information

© The Chinese Society of Theoretical and Applied Mechanics and Technology 2009

Authors and Affiliations

  • Xinming Qiu
    • 1
  • Lianghong He
    • 1
  • Yueqiang Qian
    • 1
  • Xiong Zhang
    • 1
  1. 1.Department of Engineering MechanicsTsinghua UniversityBeijingChina

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