*EOS

ProductsAbaqus/Explicit

TypeModel data

LevelModel

Required parameters

TYPE

Set TYPE=IDEAL GAS for an ideal gas equation of state.

Set TYPE=IGNITION AND GROWTH for an ignition and growth equation of state; if this equation of state is used, the REACTION RATE option and the GAS SPECIFIC HEAT option are required.

Set TYPE=JWL for an explosive equation of state; if this equation of state is used, the DETONATION POINT option is required.

Set TYPE=TABULAR for a tabulated equation of state that is linear in energy.

Set TYPE=USER for a user-defined equation of state that is defined in user subroutine VUEOS.

Set TYPE=USUP for a linear $U_{s} - U_{p}$ equation of state.

Optional parameters

DETONATION ENERGY

This parameter can be used only in combination with TYPE=IGNITION AND GROWTH.

Set this parameter equal to the energy of detonation. The default value is 0.0.

PROPERTIES

This parameter can be used only if the USER parameter is specified.

Set this parameter equal to the number of property values needed as data in user subroutine VUEOS. The default value is 0.

Data line for an ideal gas equation of state (TYPE=IDEAL GAS)

First (and only) line

Gas constant, R. (Units of JM⁻¹ $θ$ ⁻¹.)
The ambient pressure, $p_{A}$ (Units of FL⁻²). If this field is left blank, a default of $0.0$ is used.

Data lines for an ignition and growth equation of state (TYPE=IGNITION AND GROWTH)

First line

Material constants used in the equation of state for unreacted explosive.

$A_{s}$ . (Units of FL⁻².)
$B_{s}$ . (Units of FL⁻².)
$ω_{s}$ . (Dimensionless.)
$R_{1 s}$ . (Dimensionless.)
$R_{2 s}$ . (Dimensionless.)

Second line

Material constants used in the equation of state for reacted products.

$A_{g}$ . (Units of FL⁻².)
$B_{g}$ . (Units of FL⁻².)
$ω_{g}$ . (Dimensionless.)
$R_{1 g}$ . (Dimensionless.)
$R_{2 g}$ . (Dimensionless.)

Data line for an explosive equation of state (TYPE=JWL)

First (and only) line

Detonation wave speed, $C_{d}$ . (Units of LT⁻¹.)
A. (Units of FL⁻².)
B. (Units of FL⁻².)
$ω$ . (Dimensionless.)
$R_{1}$ . (Dimensionless.)
$R_{2}$ . (Dimensionless.)
Detonation energy density, $E_{0}$ . (Units of JM⁻¹.)
Pre-detonation bulk modulus, $K_{p d}$ . (Units of FL⁻².)

Data line for a tabulated equation of state (TYPE=TABULAR), where the volumetric strain values must be arranged in descending order

First line

$f_{1}$ . (Units of FL⁻².)
$f_{2}$ . (Dimensionless.)
Volumetric strain $ε_{vol}$ . (Dimensionless.)

Repeat this data line as often as necessary to define the dependence of $f_{1}$ and $f_{2}$ on volumetric strain.

Data line for a linear equation of state (TYPE=USUP)

First (and only) line

$c_{0}$ . (Units of LT⁻¹.)
s. (Dimensionless.)
$Γ_{0}$ . (Dimensionless.)

Data lines to define the material properties for a user-defined equation of state (TYPE=USER)

No data lines are needed if the PROPERTIES parameter is omitted or set to 0. Otherwise, first line

Material properties, eight per line.

Repeat this data line as often as necessary to define the material properties.