*MAT_121 (GENERAL_NONLINEAR_1DOF_DISCRETE_BEAM)

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

Format

(1) (2) (3) (4) (5) (6) (7) (8)
*MAT_121 or *MAT_GENERAL_NONLINEAR_1DOF_DISCRETE_BEAM
mat_ID ρ i K H        
LCL LCU LCD          
FAILT FAILC            

Definition

Field Contents SI Unit Example
mat_ID Material identifier.

(Integer)

ρ i Initial density.

(Real)

[ kg m 3 ]
K Stiffness.

(Real)

[ N m ]
H Unloading option.
= 0 (Default)
Elastic spring.
= 1
Nonlinear unloading and isotropic hardening.
= 2
Elastic hysteresis in unloading.
= 3
Nonlinear elastic plastic spring with nonlinear unloading.

(Real)

 
LCL Curve identifier for force versus displacement loading curve.

(Integer)

 
LCU Curve identifier for force versus displacement unloading curve.

(Integer)

 
LCD Curve identifier for force versus velocity damping curve.

(Integer)

 
FAILT Failure elongation in tension.

(Real)

[ m ]
FAILC Failure elongation in compression.

(Real)

[ m ]

Comments

  1. This keyword maps to /MAT/LAW108 (SPR_GENE) with one degree of freedom (DOF).
  2. DOF directions are defined by the coordinate system defined in *SECTION_BEAM. By default, the global coordinate system is used.
  3. This material is only used with discrete beams ELFORM=6 and CA > 0 in *SECTION_BEAM.
  4. Beam elements with zero initial length are recommended.
  5. 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.