*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

(1) (2) (3) (4) (5) (6) (7) (8)
*MAT_077_O or *MAT_OGDEN_RUBBER
mat_ID ρ i ν N_pair
If N_pair = 0, insert these two lines.
(1) (2) (3) (4) (5) (6) (7) (8)
μ1 μ2 μ3 μ4 μ5
α1 α2 α3 α4 α5
If N_pair > 0, insert this line.
(1) (2) (3) (4) (5) (6) (7) (8)
SGL SW ST Fct_ID DATA
In all cases, add up to 12 lines.
(1) (2) (3) (4) (5) (6) (7) (8)
Gi β i    

Definition

Field Contents SI Unit Example
mat_ID Material identifier

(Integer)

ρ i Initial density

(Real)

[ 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)

[ N m ]
DATA Experimental data type
= 1 (Default)
Uniaxial test data

(Integer)

Gi Shear modulus for relaxation [ Pa ]
β i Decay constant for relaxation [ 1 s ]

Comments

  1. This keyword maps to /MAT/LAW42 (OGDEN) (if N_pair = 0) or /MAT/LAW69 (N_pair > 0).
  2. 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.