MATVE

Format

Example

Definitions

Comments

1. The CHEXA, CTETRA, CPENTA, and CPYRA elements are currently supported.
2. The instantaneous response can be provided by MAT1, MAT9 or MATHE entries, which should have the same MID as the MATVE entry.
3. The viscoelastic material is represented by the generalized Maxwell model. The material response is given by the following convolution representation.(1)
   $$\sigma ={\displaystyle {\int }_0^{t}g\left(t-s\right){\dot{\sigma }}_{0}ds}$$
   Where,(2)

   $$g\left(t\right)={\gamma }_{\infty }+{\displaystyle \sum _i{\gamma }_i{e}^{-\frac{t}{{\tau }_i}}}$$
   The subscript $i$ indicates the $i$ -th component in the Prony series. A maximum of 5 components are allowed.

   ${\gamma }_i$

   Modulus ratio

   ${\tau }_i$

   Relaxation time

   ${\sigma }_0$

   Instantaneous stress response

4. For the isotropic model, the deviatoric and bulk responses can be specified separately. For the anisotropic model, only gDi and tDi are used and the bulk specifications are ignored.
5. The material relaxation response is controlled by the card VISCO. For example, if the user wants to simulate a physical relaxation test, the first subcase can omit the VISCO card so that material response is only the instantaneous elasticity in this subcase. In the next subcase, the user can add a VISCO card so that the material response is viscoelastic.
6. For Implicit Nonlinear Analysis, MATVE is supported for small displacement and large displacement nonlinear analysis.