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 or GZX < 0, an error termination will occur.

PARAM,CHECKMAT,NO will disable this error.
Not all zeros If GZX = 0, a warning is provided.
Consistency none

Comments

  1. By substitution of (1)
    NUXTH EX = NUTHX ETH ,       NUXZ EX = NUZX EZ ,       NUTHZ ETH = NUZTH EZ

    into

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

    it can be expressed in terms of(2)
    NUXTH 2 * ETH EX + NUTHZ 2 * EZ ETH + NUZX 2 * EX EZ + 2 * NUXTH * NUTHZ * NUZX = 1