*MAT_119 (GENERAL_NONLINEAR_6DOF_DISCRETE_BEAM)

LS-DYNA Input Interface KeywordDefines a nonlinear elasto-plastic discrete beam material with 6 degrees of freedom (DOFs). Different loading and unloading behavior can be specified.

Format

(1)	(2)	(3)	(4)	(5)	(6)
MAT_119 or MAT_GENERAL_NONLINEAR_6DOF_DISCRETE_BEAM
`mat_ID`	$ρ_{i}$	`KT`	`KR`	`H`
`T_r`	`T_s`	`T_t`	`R_r`	`R_s`	`R_t`
`TU_r`	`TU_s`	`TU_t`	`RU_r`	`RU_s`	`RU_t`
`TD_r`	`TD_s`	`TD_t`	`RD_r`	`RD_s`	`RD_t`
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`ufT_r`	`ufT_s`	`ufT_rt`	`wfT_r`	`wfT_s`	`wfT_t`
`ufC_r`	`ufC_s`	`ufC_rt`	`wfC_r`	`wfC_s`	`wfC_t`
Blank Line

Definition

Field	Contents	SI Unit Example
`mat_ID`	Material identifier (Integer)
$ρ_{i}$	Initial density (Real)	$[\frac{kg}{m^{3}}]$
`KT`	Stiffness for translational DOFs (Real)	$[\frac{N}{m}]$
`KR`	Stiffness for rotational DOFs (Real)	$[\frac{Nm}{rad}]$
`H`	Unloading spring hardening flag = 0 (Default) Elastic spring = 1 Nonlinear unloading and isotropic hardening = 2 Elastic hysteresis in unloading (Integer)
`T_r`, `T_s`, `T_t`	Curve identifier for force vs displacement loading curve in the r, s, and t directions. (Integer)
`R_r`, `R_s`, `R_t`	Curve identifier for moment vs rotation loading curve in the r, s, and t directions. (Integer)
`TU_r`,`TU_s`¸ `TU_T`	Curve identifier for force vs displacement unloading curve in the r, s, and t directions. (Integer)
`RU_r`, `RU_s`, `RU_t`	Curve identifier for moment vs rotation unloading in the r, s, and t directions (Integer)
`TD_r`, `TD_s`, `TD_t`	Curve identifier for force vs velocity damping curve in the r, s, and t directions (Integer)
`RD_r`, `RD_s`, `RD_t`	Curve identifier for moment vs rotational velocity damping curve in the r, s, and t directions (Integer)
`ufT_r`,`ufT_s`, `ufT_t`	Failure displacement in tension input as a positive value in the r, s, and t directions. (Real)	$[m]$
`wfT_r`, `wfT_s`, `wfT_t`	Failure rotation in tension input as a positive value in the r, s, and t directions. (Real)	$[rad]$
`ufC_r`, `ufC_s`, `ufC_t`	Failure displacement in compression input as a positive value in the r, s, and t directions. (Real)	$[m]$
`wfC_r`, `wfC_s`, `wfC_t`	Failure rotation in compression input as a positive value in the r, s, and t directions. (Real)	$[rad]$

Comments

This keyword maps to /MAT/LAW108 (SPR_GENE) with six degrees of freedom (DOF).
DOF directions are defined by the coordinate system defined in *SECTION_BEAM. By default, the global coordinate system is used.
This material is only used with discrete beams ELFORM = 6 and CA>0 in *SECTION_BEAM.
Beam elements with zero initial length are recommended.
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.