/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 |
Definition
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) |
|
K1 | Material parameter. (Real) |
|
P0 | Initial pressure. (Real) |
|
Psh | Pressure shift. (Real) |
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
Elastic Solid - Sodium Chloride (NaCl)
# RHO_I RHO_0
2.16e-3 0
# E nu
39980.0 0.26
# a b n eps_max sigma_max
1E20 0 0 0 0
# Pmin
0
/EOS/MURNAGHAN/7
Sodium Chloride (NaCl) at atmospheric pressure
# K0 K1 P0 PSH
24000 5.390 .1 0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#enddata
Comments
- This equation of state is also known as Tait
Equation of State.
Where and are material parameters.
- This equation can also be found with
the following form:
With, and
- In some publications, the material parameters and are replaced by and with, and .
- Another way to express this equation
is with the compressibility
.
with
- Murnaghan EOS does not depend on energy.
- Equations of state are used by Radioss to compute the hydrodynamic pressure and are compatible with the material laws:
1 Murnaghan, F. D. "The
compressibility of media under extreme pressures." Proceedings of the National Academy of
Sciences 30, no. 9 (1944): 244-247