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*HYPERFOAM

Keyword type: model definition, material

This option is used to define a hyperfoam material. There is one optional parameters, N. N determines the order of the strain energy potential. Default is N=1. All constants may be temperature dependent.

The hyperfoam strain energy potential takes the form

$\displaystyle U=\sum_{i=1}^{N} \frac{2 \mu_i}{\alpha_i^2} \left[ \lambda_1^{\al...
...ha_i}+\lambda_3^{\alpha_i}-3+\frac{1}{\beta_i}(J^{-\alpha_i \beta_i}-1) \right]$ (206)

where $ \lambda_1$, $ \lambda_2$ and $ \lambda_3$ are the principal stretches. The parameters $ \beta_i$ are related to the Poisson coefficients $ \nu_i$ by:

$\displaystyle \beta_i=\frac{ \nu_i}{1 -2 \nu_i}$ (207)

and

$\displaystyle \nu_i= \frac{ \beta_i}{1+2 \beta_i}.$ (208)


First line:

Following line for N=1:

Repeat this line if needed to define complete temperature dependence.

Following line for N=2:

Repeat this line if needed to define complete temperature dependence.

Following lines, in a pair, for N=3: First line of pair:

Second line of pair: Repeat this pair if needed to define complete temperature dependence.

Example:

*HYPERFOAM,N=2
0.164861,8.88413,2.302e-5,-4.81798,0.,0.

defines a hyperfoam material with two terms in the series.


Example files: beamhf.


next up previous contents
Next: *INCLUDE Up: Input deck format Previous: *HYPERELASTIC   Contents
guido dhondt 2012-10-06