*MAT_074 (ELASTIC_SPRING_DISCRETE_BEAM)

LS-DYNA Input Interface KeywordThis keyword defines a nonlinear elasto-plastic discrete beam material with one DOFs and optional preload option.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)
*MAT_074 or *MAT_ELASTIC_SPRING_DISCRETE_BEAM
mat_ID	${\rho }_i$	K	F0	D	FC	FT
LCF	LCD	C1	C2	V0

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	LCF=0: Stiffness LCF>0: scaling coefficient for curve LCF ordinate (Real)	$\left[\frac{\text{N}}{\text{m}}\right]$
F0	Initial force (Real)	$\left[\text{N}\right]$
D	Linear damping coefficient (Real)
FC, FT	Failure elongation in compression and in tension (both should be input as positive values) (Real)	$\left[\text{m}\right]$
LCF	Force vs displacement curve identifier (Integer)
LCD	Damping force vs velocity identifier (Integer)
C1, C2	Nonlinear damping coefficients
V0	Reference velocity for nonlinear damping calculation	$\left[\frac{\text{m}}{\text{s}}\right]$

Comments

1. This keyword maps to /MAT/LAW108 (SPR_GENE) with one DOF.
2. Stiffness direction is defined by coordinate system referenced in *SECTION_BEAM. This is global coordinate system by default.
3. Beams with zero initial length are recommended.
4. The material is only used with *SECTION_BEAM, ELFORM = 6 discrete beam elements.
5. 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.