/EOS/MURNAGHAN

Block Format Keyword Describes the Murnaghan equation of state.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/EOS/MURNAGHAN/mat_ID/unit_ID
eos_title
K0 K1 P0 Psh ρ 0

Definitions

Field Contents SI Unit Example
mat_ID Material identifier.

(Integer, maximum 10 digits)

 
unit_ID Unit Identifier.

(Integer, maximum 10 digits)

 
eos_title EOS title.

(Character, maximum 100 characters)

 
K0 Material parameter.

(Real)

[ Pa ]
K1 Material parameter.

(Real)

 
P0 Initial pressure.

(Real)

[ Pa ]
Psh Pressure shift.

(Real)

[ Pa ]
ρ 0 Reference density.

Default = material density (Real)

[ kg m 3 ]

Example

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/UNIT/1
unit for mat
                   g                  mm                  ms
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/MAT/HYDPLA/7
IDEAL-GAS
#              RHO_I               RHO_0
             1.22e-3             1.22e-3
#                  E                  nu
                   0                   0
#                  a                   b                   n             eps_max           sigma_max
                1E30                   0                   0                   0                   0
#               Pmin 
                   0
/EOS/MURNAGHAN/7
NaCl  
#                 K0                  K1                  P0                 PSH                RHO0      
                24.0               5.390                 1.0                   0            2.165e-3
/ALE/MAT/7

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#enddata

Comments

  1. This equation of state is also known as Tait Equation of State.(1)
    P ( V ) = K 0 K 1 [ ( V V 0 ) K 1 1 ]

    Where K0 and K1 are material parameters.

  2. Equations of state are used by Radioss to compute the hydrodynamic pressure and are compatible with the material laws:
    • /MAT/LAW3 (HYDPLA)
    • /MAT/LAW4 (HYD_JCOOK)
    • /MAT/LAW6 (HYDRO or HYD_VISC)
    • /MAT/LAW10 (DPRAG1)
    • /MAT/LAW12 (3D_COMP)
    • /MAT/LAW49 (STEINB)
    • /MAT/LAW102 (DPRAG2)
    • /MAT/LAW103 (HENSEL-SPITTEL)
1 Murnaghan, F. D. "The compressibility of media under extreme pressures." Proceedings of the National Academy of Sciences 30, no. 9 (1944): 244-247