In the Rocks subnode you define the properties for modeling materials with failure criteria representative of rocks. This material model can be used together with Linear Elastic Material and Nonlinear Elastic Material. It is available with the Geomechanics Module.

Select a Rock criterion — Original Hoek-Brown or Generalized Hoek-Brown. The defaults are taken From material. For User defined choices, enter other values or expressions.

The defaults for the Uniaxial compressive strength σc, Hoek-Brown m parameter m, and Hoek-Brown s parameter s are taken From material.

The defaults for the Uniaxial compressive strength σc, Geological strength index GSI, Disturbance factor D, and Intact rock parameter mi are taken From material.

If required, select either None or Principal stress cut-off (see Tension Cut-Off).

When Principal stress cut-off is selected from the list, enter a value or expression for the Maximum tensile stress σt. Use this to constrain the rock model with an extra yield surface, which limits the maximum principal tensile stress.

Physics tab with Linear Elastic Material or Nonlinear Elastic Material node selected in the model tree: