*MAT_S08 (SPRING_INELASTIC)

LS-DYNA Input Interface KeywordThis keyword defines a nonlinear spring material with stiffness available only in tension or in compression.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)
MAT_S08 or MAT_SPRING_INELASTIC
`mat_ID`	`LCFD`		`CTF`

Definition

Field	Contents	SI Unit Example
`mat_ID`	Material identifier (Integer)
`LCFD`	Loading curve identifier: force vs displacement or moment vs rotation angle. The curve should start with (0, 0) and be defined in first quadrant only. (Integer)
`CTF`	= -1.0 Tension only spring = 1.0 (Default) Compression only spring (Integer)

Field

Contents

SI Unit Example

mat_ID

Material identifier

(Integer)

LCFD

Loading curve identifier: force vs displacement or moment vs rotation angle. The curve should start with (0, 0) and be defined in first quadrant only.

(Integer)

CTF

= -1.0: Tension only spring
= 1.0 (Default): Compression only spring

(Integer)

Comments

This keyword maps to /PROP/TYPE8 (SPR_GENE) spring using a default mass 2.0e-03 kg and inertia 2e-02 kg*mm depending on the units.
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.