*MAT_076 (GENERAL_VISCOELASTIC)

LS-DYNA Input Interface KeywordDefines an isotropic, visco-elastic material. It is generally used to model incompressible elastomers.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)
*MAT_076 or *MAT_GENERAL_VISCOELASTIC
mat_ID	${\rho }_i$	K
LCIDG	N			LCIDK

Optional lines:

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)
GI	BETAI	KI	BETAK

Definition

Field	Contents	SI Unit Example
mat_ID	Material identifier. (Integer)
${\rho }_i$	Initial density. (Real)	$\left[\frac{\text{kg}}{{\text{m}}^{\text{3}}}\right]$
K	Bulk coefficient. (Real)	$\left[\text{Pa}\right]$
LCIDG	Function for shear modulus from relaxation test as function of time. (Integer)
N	Number of terms in fitting relaxation test. (Integer)
LCIDK	Function for bulk modulus from relaxation test as function of time. (Integer)
GI	Ith shear modulus in Prony series.	$\left[\text{Pa}\right]$
BETAI	Ith decay coefficient Prony series for shear.
KI	Ith bulk modulus in Prony series.	$\left[\text{Pa}\right]$
BETAK	Ith decay coefficient Prony series for bulk.

Comments

1. This keyword maps to /MAT/LAW42 (OGDEN) + /VISC/PRONY and is compatible with shell and solid elements.
2. The option “_TITLE” can be added to the end of this keyword. When “_TITLE” is included, an extra 80 characters long line is added after the keyword input line which allows an entity title to be defined.