MATVP

Format

Example

Definitions

Comments

1. CHEXA, CTETRA, CPENTA, CPYRA elements are supported.
2. Specifying a MAT1 and a MATVP with the same MID allows modeling creep material. Specifying a MAT1, a MATS1 and a MATVP with the same MID can model a creep material with plasticity.
3. You can choose explicit or implicit time integration for creep materials by using the TINT field of the VISCO card.
4. The STRAIN hardening formulation is:(1)
   $${\dot{\overline{\epsilon }}}^c=A^{\frac{1}{m+1}}{\overline{\sigma }}^{\frac{n}{m+1}}{\left(\left(m+1\right){\overline{\epsilon }}^c\right)}^{\frac{m}{m+1}}$$
   The TIME hardening formulation is:(2)

   $${\dot{\overline{\epsilon }}}^c=A{\overline{\sigma }}^n{t}^m$$
   Where,

   ${\dot{\overline{\epsilon }}}^c=\sqrt{\frac{2}{3}{\dot{\epsilon }}^c:{\dot{\epsilon }}^c}$

   Equivalent creep strain rate

   $\overline{\sigma }$

   Equivalent deviatoric stress

   $t$

   Total time

5. The units for $A$ is $F^{-n}{L}^{2n}{T}^{-(m+1)}$ .
   Where,

   $F$

   Force

   $L$

   Length

   $T$

   Time

   You might consider switching to another set of units if the value of $A$ is too small.

6. A VISCO Subcase Entry is mandatory to conduct creep material analysis in a particular subcase.
7. MATVE is supported for small displacement and large displacement nonlinear analysis.