II.1.10.24 3D honeycomb criterion

A general honeycomb criterion uses the out-of-plane tension/compression and the two out-of-plane shear components of the Cauchy stress tensor. The criterion read as follows:

The allowable ${\sigma }_{33}^{\text{all}}$ depends on the sign of ${\sigma }_{33}$ (Generally, the compressive allowable is significantly smaller than the tensile one). The honeycomb material is generally defined in such a way that the allowable ${\tau }_{31}^{\text{all}}={\tau }_L$ is in ribbon direction (longitudinal allowable) and ${\tau }_{23}^{\text{all}}$ is the transverse allowable ${\tau }_W$. Core passes the failure criterion if the following condition is satisfied

The reserve factor is calculated as follows:

and the strength ratio is given by:

This criterion is referred to as “Honey3D” in FeResPost.