*MAT_077_O (OGDEN_RUBBER)

LS-DYNA Input Interface KeywordThis keyword defines an isotropic, hyperelastic, viscous, and incompressible material specified using the Ogden material models.

Format

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MAT_077_O or MAT_OGDEN_RUBBER
`mat_ID`	$ρ_{i}$	`ν`	`N_pair`

If N_pair = 0, insert these two lines.

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`μ1`	`μ2`	`μ3`	`μ4`	`μ5`
`α1`	`α2`	`α3`	`α4`	`α5`

If N_pair > 0, insert this line.

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`SGL`	`SW`	`ST`	`Fct_ID`	`DATA`

In all cases, add up to 12 lines.

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`Gi`	$β$ `i`

Definition

Field	Contents	SI Unit Example
`mat_ID`	Material identifier (Integer)
$ρ_{i}$	Initial density (Real)	$[\frac{kg}{m^{3}}]$
`v`	Poisson’s ratio Default = 0.495 (Real)
`N_pair`	The number of material parameter (`μi` and `αi`) pairs calculated in the representation of the strain energy density function (W). The material parameters are calculated from the given stress-strain curve (`fct_ID`). `(N_pair` ≤ 5) Default = 2 (Integer)
`μ1` - `μ5`	Parameter of the shear hyperelastic modulus (Real)	$[Pa]$
`α1` - `α5`	Exponent of the shear hyperelastic modulus (Real)
`SGL`	Specimen gauge length	$[m]$
`SW`	Specimen width length	$[m]$
`ST`	Specimen thickness	$[m]$
`Fct_ID`	Function identifier for the force versus change in gauge length. Compression is defined in the 3rd quadrant (negative) and Tensile is defined in the 1st quadrant (positive). (Integer)	$[\frac{N}{m}]$
`DATA`	Experimental data type = 1 (Default) Uniaxial test data (Integer)
`Gi`	Shear modulus for relaxation	$[Pa]$
$β$ `i`	Decay constant for relaxation	$[\frac{1}{s}]$

Comments

This keyword maps to /MAT/LAW42 (OGDEN) (if N_pair = 0) or /MAT/LAW69 (N_pair > 0).
The option “_TITLE” can be added to the end of this keyword. When “_TITLE” is included, an extra 80 character long line is added after the keyword input line which allows an entity title to be defined.