*MAT_083 (FU_CHANG_FOAM)

LS-DYNA Input Interface KeywordDefines an isotropic, highly compressible Fu Chang foam.

Format

(1) (2) (3) (4) (5) (6) (7) (8)
*MAT_083 or *MAT_FU_CHANG_FOAM
mat_ID ρ i E   TC FAIL DAMP TBID
      TFLAG HU
              SHAPE
ALPHA              

Definition

Field Contents SI Unit Example
mat_ID Material identifier.

(Integer)
ρ i Initial density.

(Real)

 [ kg m 3 ]
E Young’s modulus.

(Real)

 [ Pa ]
TC Tension cut off stress.

(Real)

 [ Pa ]
FAIL Element erosion.
= 0
No failure model in the material.
= 2
Element is deleted when principal stress is larger than TC.

(Real)

  
DAMP Viscous damping coefficient.

Default = 0.05 (Real)

  
TBID Table identifier for engineering stress versus engineering strain for different strain rates. Positive strains and stresses correspond to compression.

(Real)
TFLAG Tension flag.
= 0
Linear in tensile (follow E).
= 1
Nonlinear in tensile (follow the curves defined in the 3rd quadrant of the table TBID).

(Real)

  
HU Hysteresis unloading factor.

0 < HU < 1

(Real)
SHAPE Shape unloading factor.

(Real)
ALPHA Exponent for unloading.  

Comments

  1. This keyword maps to /MAT/LAW90.
  2. The unloading follows the first loading curve when HU = 0. For HU > 0, the first loading curve is used to calculate the unloading path based on a damage formulation.
  3. 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.