# Material Property Checks for MAT3

MAT3 only applies to axisymmetric elements.

Material Requirements | MAT3 |
---|---|

Mathematical | If EX = 0, ETH = 0, EZ = 0
or NUXTH * NUTHX + NUTHZ * NUZTH + NUZX * NUXZ + 2 * NUXTH * NUTHZ * NUZX = 1, an error termination will occur. 1 |

Semi-stability | If EX < 0, ETH < 0,
EZ < 0, GZX < 0, GXTH < 0, or GTHZ < 0, an error
termination will
occur. PARAM, |

Not all zeros | If GZX = 0, a warning is provided. |

Consistency | none |

## Comments

- By substitution of
$$\frac{\text{NUXTH}}{\text{EX}}=\frac{\text{NUTHX}}{\text{ETH}},\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\frac{\text{NUXZ}}{\text{EX}}=\frac{\text{NUZX}}{\text{EZ}},\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\frac{\text{NUTHZ}}{\text{ETH}}=\frac{\text{NUZTH}}{\text{EZ}}$$
into

NUXTH * NUTHX + NUTHZ * NUZTH + NUZX * NUXZ + 2 * NUXTH * NUTHZ * NUZX = 1,

it can be expressed in terms of

$$\frac{{\text{NUXTH}}^{2}*\text{ETH}}{\text{EX}}+\frac{{\text{NUTHZ}}^{2}*\text{EZ}}{\text{ETH}}+\frac{{\text{NUZX}}^{2}*\text{EX}}{\text{EZ}}+2*\text{NUXTH}*\text{NUTHZ}*\text{NUZX}=1$$