Graphical representation of Mohr-Coulomb plasticity surface in principal stress space

What can be modified:
  • cohesion, c
  • internal friction angle, φ:
  • the choice of displayed elements - it si possible to show or hide
    • section corresponding to plastically admissible area for plane stress,
    • axes corresponding to principal stresses,
    • hydrostatic axis,
    • plasticity surface itself.
  • View direction on the 3D picture can be modified with mouse (placing cursor on the picture, drag and drop).
  • It is also possible to choose a predefined view:
    • parallel to one principal stress axis (button "|| σ3"),
    • perpendicular to hydrostatic axis (button "⟂ (σ1=σ2=σ3)"),
    • parallel to hydrostatic axis (button "|| (σ1=σ2=σ3)").
  • Mohr-Coulomb plasticity surface is a hxagonal pyramid with the top on hydrostatic axis.
  • The section corresponding to plane stress results in hexagon with one axis of symmetry.
  • The deviatoric section results in (non-regular) hexagon with three axes of symmetry.
  • While modifying cohesion, the pyramid is translated along hydrostatic axis.
  • While modifying internal friction angle, the top angle of the pyramid is changed.
  • For zero internal friction angle, the pyramid transfers to prism corresponding to Tresca plasticity surface.
Contact: jan.stransky(at)
Last update: 25th September 2018
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