Von Mises criterion (2D)

Using the stress tensor components a scalar equivalent shear stress is given by:

σ_{eq}^{VonMises2D} = \sqrt{σ_{11}^{2} + σ_{22}^{2} - σ_{11} σ_{22} + 3 τ_{12}^{2}} .

Ply passes the failure criterion if

σ_{eq}^{VonMises2D} \leq σ_{t}^{all} .

The corresponding failure index is:

F I^{VonMises2D} = \frac{σ_{eq}^{VonMises2D}}{σ_{t}^{all}},

(II.1.116)

The reserve factor is given by:

R F^{VonMises2D} = \frac{1}{F o S \cdot F I^{VonMises2D}} = \frac{σ_{t}^{all}}{F o S \cdot σ_{eq}^{VonMises2D}},

(II.1.117)

and the strength ratio by:

S R^{VonMises2D} = F o S \cdot F I^{VonMises2D} = \frac{F o S \cdot σ_{eq}^{VonMises2D}}{σ_{t}^{all}} .

(II.1.118)

This criterion is referred to as “VonMises2D” criterion in FeResPost.