Iform = 1
Block Format Keyword This material is able to handle up to three elasto plastic materials (solid, liquid, or gas). The material law is based on a diffusive interface technique.
- P
- Positive for a compression and negative for traction.
Where, means that the EOS is linear for an expansion and cubic for a compression.
By default process is adiabatic . To enable thermal computation, refer to 6.
Format
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
/MAT/LAW51/mat_ID/unit_ID | |||||||||
mat_title | |||||||||
Blank | |||||||||
Iform |
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
Pext |
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
Definitions
Field | Contents | SI Unit Example |
---|---|---|
mat_ID | Material identifier. (Integer, maximum 10 digits) |
|
unit_ID | Unit Identifier. (Interger, maximum 10 digits) |
|
mat_title | Material title. (Character, maximum 100 characters) |
|
Iform | Formulation flag. (Integer) |
|
Pext | External pressure. 2 Default = 0 (Real) |
|
Kinematic viscosity shear
. 3 Default = 0 (Real) |
||
Kinematic viscosity (volumetric),
which corresponds to
Stokes Hypothesis. 3 Default = 0 (Real) |
||
Initial volumetric fraction. 4 (Real) |
||
Initial density. (Real) |
||
Initial energy per unit
volume. (Real) |
||
Hydrodynamic cavitation pressure. 5 If fluid material ( ), then default = . If solid material ( ), then default = -1e30. (Real) |
||
Initial pressure. (Real) |
||
Hydrodynamic coefficient. (Real) |
||
Hydrodynamic coefficient. (Real) |
||
Hydrodynamic coefficient. (Real) |
||
Hydrodynamic coefficient. (Real) |
||
Hydrodynamic coefficient. (Real) |
||
Elasticity shear modulus.
(Real) |
||
Plasticity yield stress. (Real) |
||
Plasticity hardening
parameter. (Real) |
||
Plasticity hardening exponent. Default = 1.0 (Real) |
||
Strain rate coefficient.
Default = 0.00 (Real) |
||
Reference strain rate. If , no strain rate effect (Real) |
||
Temperature exponent. Default = 1.00 (Real) |
||
Initial temperature. Default = 300 K (Real) |
||
Melting temperature.
Default = 1030 (Real) |
||
Maximum temperature. Default = 1030 (Real) |
||
Specific heat per unit of volume. 7 (Real) |
||
Failure plastic strain. Default = 1030 (Real) |
||
Plasticity maximum stress. Default = 1030 (Real) |
||
Thermal conductivity coefficient 1. 8 (Real) |
||
Thermal conductivity coefficient 2. 8 (Real) |
Example
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/MAT/LAW51/1
99.99% Water + 0.01% Air-MULTIMAT:AIR+WATER+COPPER,units{kg,m,s,Pa}
#(output is relative pressure to Pext=1E+5Pa)
#--------------------------------------------------------------------------------------------------#
# Material Law No 51. MULTI-MATERIAL SOLID LIQUID GAS -ALE-CFD-SPH
#--------------------------------------------------------------------------------------------------#
# Blank format
# IFORM
1
#---Global parameters------------------------------------------------------------------------------#
# P_EXT NU LAMDA
1E+5 0 0
#---Material#1:AIR(PerfectGas)---------------------------------------------------------------------#
# ALPHA_1 RHO_0_1 E_0_1 P_MIN_1 C_0_1
0.0001 1.2 2.5E+05 0 -1E+5
# C_1_1 C_2_1 C_3_1 C_4_1 C_5_1
0 0 0 0.4 0.4
# G_1 SIGMA_Y_1 BB_1 N_1
0 0 0 0
# CC_1 EPSILON_DOT_0_1
0 0
# CM_1 T_10 T_1MELT T_1LIMIT RHOCV_1
0 0 0 0 0
# EPSILON_MAX_1 SIGMA_MAX_1 K_A_1 K_B_1
0 0 0 0
#---Material#2:WATER(Linear_Incompressible)--------------------------------------------------------#
# ALPHA_2 RHO_0_2 E_0_2 P_MIN_2 C_0_2
0.9999 1000.0 0 0 0
# C_1_2 C_2_2 C_3_2 C_4_2 C_5_2
2.25E+9 0 0 0 0
# G_2 SIGMA_Y_2 BB_2 N_2
0 0 0 0
# CC_2 EPSILON_DOT_0_2
0 0
# CM_2 T_20 T_2MELT T_2LIMIT RHOCV_2
0 0 0 0 0
# EPSILON_MAX_2 SIGMA_MAX_2 K_A_2 K_B_2
0 0 0 0
#---Material#3:OFHC COPPER(elastic plastic solid:Mie_Gruneisen+JCook)------------------------------#
# ALPHA_3 RHO_0_3 E_0_3 P_MIN_3 C_0_3
0.0 8930.0 0 0 0
# C_1_3 C_2_3 C_3_3 C_4_3 C_5_3
1.389E+11 1.379E+11 -0.351E+11 0.97 0.97
# G_3 SIGMA_Y_3 BB_3 N_3
47.7E+9 120E+6 292E+6 0.31
# CC_3 EPSILON_DOT_0_3
0.025 1
# CM_3 T_30 T_3MELT T_3LIMIT RHOCV_3
1.09 300 1790 0 3.42019E+6
# EPSILON_MAX_3 SIGMA_MAX_3 K_A_3 K_B_3
0 1.2E+9 0 0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
Comments
- Numerical diffusion can be improved using the second order method for volume fraction convection, /ALE/MUSCL. The previous /UPWIND used to limit diffusion is now obsolete.
- Radioss
computes and outputs a relative pressure
.
(6) However, total pressure is essential for energy integration ( ). It can be computed with the external pressure flag Pext.
leads to .
This means that if Pext = 0, the computed pressure is also the total pressure: .
- Kinematic viscosities are global and is
not specific to each material. It allows computing
viscous stress tensor:
(7) Where,- Cinematic shear viscosity flag
- Cinematic volumetric viscosity flag
- Volumetric fractions enable the sharing
of elementary volume within the three different
materials.
For each material must be defined between 0 and 1.
Sum of initial volumetric fractions must be equal to 1.
For automatic initial fraction of the volume, refer to the /INIVOL card.
-
flag is the minimum
value for the computed pressure
. It means that total
pressure is also bounded to:
(8) For fluid materials and detonation products, must remain positive to avoid any tensile strength so must be set to .
For solid materials, default value = 1e-30 is suitable but may be modified.
- Heat contribution is computed only if the
thermal card is associated to the material law
(/HEAT/MAT).In this case, and the parameters for thermal diffusion are read for each material:
(9) For solids and liquids, for perfect gas:
- The temperature evolution in the Johnson-Cook model is computed with the flag , even if the thermal card (/HEAT/MAT) is not defined.
- Thermal conductivity,
, is linearly dependent
on the temperature:
(10) - Material tracking is possible through
animation
files:
/ANIM/BRIC/VFRAC (All material volumetric fractions)