Defining an equation of state

From the menu in the Edit Material dialog box, select Mechanical Eos .

(For information on displaying the Edit Material dialog box, see Creating or editing a material.)

Click the arrow to the right of the Type field, and select the type of equation of state that you want to define:

Select Ideal Gas to define an ideal gas equation of state. For more information, see Ideal Gas Equation of State.
Select JWL to define a Jones-Wilkins-Lee explosive equation of state. For more information, see JWL High Explosive Equation of State.
Select Us-Up to define a linear U_s − U_p equation of state. For more information, see Mie-Grüneisen Equations of State.
Select Ignition and growth to define an equation of state that models shock initiation and detonation wave propagation. For more information, see Ignition and Growth Equation of State.
Select Tabular to define a tabulated equation of state linear in energy. For more information, see Tabulated Equation of State.

If you selected Ideal Gas in Step 2, enter the following data in the Data table:

Gas Constant: Gas constant, R. (Units of JM⁻¹K⁻¹.)
Ambient Pressure: The ambient pressure, $p_{A}$ (Units of FL⁻²).

For detailed information on how to enter data, see Entering tabular data.

If you selected JWL in Step 2, enter the following data in the Data table:

Detonation Wave Speed: Detonation wave speed, $C_{d}$ . (Units of LT⁻¹.)
A and B: Material constants A, and B. (Units of FL⁻².)
omega, R1, and R2: Material constants $ω$ , $R_{1}$ , and $R_{2}$ . (Dimensionless.)
Detonation Energy Dens: Detonation energy density, $E_{0}$ . (Units of JM⁻¹.)
Pre-deton Bulk Modulus: Pre-detonation bulk modulus, $K_{p d}$ . (Units of FL⁻².)

For detailed information on how to enter data, see Entering tabular data.

If you selected Us-Up in Step 2, enter the following data in the Data table:

c0: Reference sound speed, $c_{0}$ . (Units of LT⁻¹.)
s: Slope of the U_s − U_p curve, s. (Dimensionless.)
Gamma0: Grüneisen ratio, $Γ_{0}$ . (Dimensionless.)

For detailed information on how to enter data, see Entering tabular data.

If you selected Tabular in Step 2, enter the following data in the Data table. The volumetric strain values must be arranged in descending order (that is, from the most tensile to the most compressive states).

f1: $f_{1}$ . (Units of FL⁻².)
f2: $f_{2}$ . (Dimensionless.)
epsilon_vol: Volumetric strain $ε_{vol}$ . (Dimensionless.)

For detailed information on how to enter data, see Entering tabular data.

If you selected Ignition and growth in Step 2, see Defining an ignition and growth equation of state for detailed instructions.

If you selected JWL in Step 2, select Detonation Point from the Suboptions menu to define detonation points for the explosive material. For detailed instructions, see Defining detonation points for an explosive material.

If you selected Us-Up or Tabular in Step 2, you can select Eos Compaction from the Suboptions menu to specify plastic compaction behavior for a ductile porous material. For detailed instructions, see Defining plastic compaction behavior for an equation of state.

If you selected JWL, Us-Up, or Tabular in Step 2, you can select Tensile Failure from the Suboptions menu to specify a tensile failure model and criterion. For detailed instructions, see Defining tensile failure for an equation of state.

Click OK to close the Edit Material dialog box. Alternatively, you can select another material behavior to define from the menus in the Edit Material dialog box (see Browsing and modifying material behaviors, for more information).