# *MAT_020 (RIGID)

LS-DYNA Input Interface KeywordDefines a rigid material assigned to a part.

## Format

(1) (2) (3) (4) (5) (6) (7) (8)
*MAT_020 or *MAT_RIGID
mat_ID ${\rho }_{i}$ E $\upsilon$
CMO CON1 CON2
LCO

## Definition

Field Contents SI Unit Example
mat_ID Material identifier.

(Integer)

${\rho }_{i}$ Initial density .

(Real)

$\left[\frac{\text{kg}}{{\text{m}}^{\text{3}}}\right]$
E Young’s modulus.

(Real)

$\left[\text{Pa}\right]$
$\upsilon$ Poisson’s ratio.

Default = 0 (Real)

CMO Rigid body boundary conditions option.
= 0.0 (Default)
No boundary conditions.
= 1.0
Boundary conditions are applied in a global coordinate system.
= -1.0
Boundary conditions are applied in a local coordinate system.

(Real)

CON1 If CMO = 1, Global system translation boundary condition.
= 0
Free.
= 1
x translation is fixed.
= 2
y translation is fixed.
= 3
z translation is fixed.
= 4
x and y translation are fixed.
= 5
y and z translation are fixed.
= 6
x and z translation are fixed.
= 7
x, y, and z translation are fixed.
If CMO=-1
Local boundary condition system identifier.

(Integer)

CON2 If CMO = 1, Global system rotation boundary condition.
= 0
Free.
= 1
x rotation is fixed.
= 2
y rotation is fixed.
= 3
z rotation is fixed.
= 4
x and y rotation are fixed.
= 5
y and z rotation are fixed.
= 6
x and z rotation are fixed.
= 7
x, y, and z rotation are fixed.
If CMO=-1
Local boundary condition system identifier.
If CMO = -1. Local system boundary conditions. Enter 6 values for translation and rotation where,
= 0
Free DOF
= 1
Fixed DOF

(6 Booleans)

Example: 101111 means the x and z translations, and all rotations are fixed. The y translation is free.

LCO Local coordinate system identifier used for time history output for CMO = -1.