### 2.2.1. Failure Criteria

All available failure criteria are listed together with their failure mode abbreviations as used in failure mode plots.

Terms:

- e = strain, s = stress

- 1 = material 1 direction, 2 = material 2 direction, 3 = out-of-plane normal direction, 12 = in-plane shear, 13 and 23 = out-of-plane shear terms

- I = principal I direction, II = principal II direction, III = principal III direction

- t = tension, c = compression

Criteria:

- Maximum Strain: e1t, e1c, e2t, e2c, e12

- Maximum Stress: s1t, s1c, s2t, s2c,s3t, s3c, s12, s23, s13

- Tsai-Wu 2-D and 3-D: tw

- Tsai-Hill 2-D and 3-D: th

- Hashin: hf (fiber failure), hm (matrix failure), hd (delamination failure)

- Puck (simplified, 2-D and 3-D Puck implementations are available): pf (fiber failure), pmA (matrix tension failure), pmB (matrix compression failure), pmC (matrix shear failure), pd (delamination)

- LaRC 2-D and 3-D: lft3 (fiber tension failure), lfc4 (fiber compression failure under transverse compression), lfc6 (fiber compression failure under transverse tension), lmt1 (matrix tension failure), lmc2/5 (matrix compression failure)

- Cuntze 2-D and 3-D: cft (fiber tension failure), cfc (fiber compression failure), cmA (matrix tension failure), cmB (matrix compression failure), cmC (matrix wedge shape failure)

- Sandwich failure criteria:

  - Wrinkling: wb (wrinkling bottom face), wt (wrinkling top face)

  - Core Failure: cf

  - Shear Crimping failure criteria: sc

- Isotropic failure criteria - Von Mises: vMe (strain) and vMs (stress)

Weighting factor: The inverse reserve factor of each failure mode is multiplied by the accordant weighting factor.

- 1: no safety

- 2: safety of two

An overview of all available failure criteria is given in the Section Failure Analysis.

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