/MAT/LAW68 (COSSER)

Block Format Keyword This law describes the honeycomb material.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/MAT/LAW68/mat_ID/unit_ID or /MAT/COSSER/mat_ID/unit_ID
mat_title
ρ i                
E11 E22 E33        
G12 G23 G31        
fct_ID11i fct_ID22i fct_ID33i Iflag1 Fscale11i Fscale22i Fscale33i
ε max11i ε max22i ε max33i        
fct_ID12i fct_ID23i fct_ID31i Iflag2 Fscale12i Fscale23i Fscale31i
ε max12i ε max23i ε max31i        
fct_ID21i fct_ID32i fct_ID13i   Fscale21i Fscale32i Fscale13i
fct_ID11r fct_ID22r fct_ID33r   Fscale11r Fscale22r Fscale33r
ε trans11r ε trans22r ε trans33r        
fct_ID12r fct_ID23r fct_ID31r   Fscale12r Fscale23r Fscale31r
ε trans12r ε trans23r ε trans31r        
fct_ID21r fct_ID32r fct_ID13r   Fscale21r Fscale32r Fscale13r

Definition

Field Contents SI Unit Example
mat_ID Material identifier

(Integer, maximum 10 digits)

 
unit_ID Unit Identifier

(Integer, maximum 10 digits)

 
mat_title Material title

(Character, maximum 100 characters)

 
ρ i Initial density

(Real)

[ kg m 3 ]
E11 Young's modulus

(Real)

[ Pa ]
E22 Young's modulus

(Real)

[ Pa ]
E33 Young's modulus

(Real)

[ Pa ]
G12 Shear modulus

(Real)

[ Pa ]
G23 Shear modulus

(Real)

[ Pa ]
G31 Shear modulus

(Real)

[ Pa ]
fct_ID11i Initial yield stress function identifier in direction 11.

(Integer)

 
fct_ID22i Initial yield stress function identifier in direction 22.

(Integer)

 
fct_ID33i Initial yield stress function identifier in direction 33.

(Integer)

 
Iflag1 Strain formulation for yield functions 11, 22, and 33.
= 0
Yield stress is a function of μ (volumetric strains)
= 1
Yield stress is a function of ε (strains)
= -1
Yield stress is a function of ε

(Integer)

 
Fscale11i Initial yield stress scale factor on function 11.

Default = 1.0 (Real)

[ Pa ]
Fscale22i Initial yield stress scale factor on function 22.

Default = 1.0 (Real)

[ Pa ]
Fscale33i Initial yield stress scale factor on function 33.

Default = 1.0 (Real)

[ Pa ]
ε max11i Initial failure strain in tension in direction 1.

(Real)

 
ε max22i Initial failure strain in tension in direction 2.

(Real)

 
ε max33i Initial failure strain in tension in direction 3.

(Real)

 
fct_ID12i Initial shear yield stress function in direction 12.

(Integer)

 
fct_ID23i Initial shear yield stress function in direction 23.

(Integer)

 
fct_ID31i Initial shear yield stress function in direction 31.

(Integer)

 
Iflag2 Strain formulation for shear yield functions 12, 23, and 31.

(Integer)

 
Fscale12i Initial shear yield stress scale factor on function 12.

Default = 1.0 (Real)

[ Pa ]
Fscale23i Initial shear yield stress scale factor on function 23.

Default = 1.0 (Real)

[ Pa ]
Fscale31i Initial shear yield stress scale factor on function 31.

Default = 1.0 (Real)

[ Pa ]
ε max12i Initial failure strain in direction 12.

(Integer)

 
ε max23i Initial failure strain in direction 23.

(Integer)

 
ε max31i Initial failure strain in direction 31.

(Integer)

 
fct_ID21i Initial shear yield stress function in direction 21.

(Integer)

 
fct_ID32i Initial shear yield stress function in direction 32.

(Integer)

 
fct_ID13i Initial shear yield stress function in direction 13.

(Integer)

 
Fscale21i Initial shear yield stress scale factor on function 21.

Default = 1.0 (Real)

[ Pa ]
Fscale32i Initial shear yield stress scale factor on function 32.

Default = 1.0 (Real)

[ Pa ]
Fscale13i Initial shear yield stress scale factor on function 13.

Default = 1.0 (Real)

[ Pa ]
fct_ID11r Residual yield stress function in direction 11.

(Integer)

 
fct_ID22r Residual yield stress function in direction 22.

(Integer)

 
fct_ID33r Residual yield stress function in direction 33.

(Integer)

 
Fscale11r Residual yield stress scale factor on function 11.

Default = 1.0 (Real)

[ Pa ]
Fscale22r Residual yield stress scale factor on function 22.

Default = 1.0 (Real)

[ Pa ]
Fscale33r Residual yield stress scale factor on function 33.

Default = 1.0 (Real)

[ Pa ]
ε trans11r Transition strain in direction 11.

(Real)

 
ε trans22r Transition strain in direction 22.

(Real)

 
ε trans33r Transition strain in direction 33.

(Real)

 
fct_ID12r Residual shear yield stress function in direction 12.

(Integer)

 
fct_ID23r Residual shear yield stress function in direction 23.

(Integer)

 
fct_ID31r Residual shear yield stress function in direction 31.

(Integer)

 
Fscale12r Residual shear yield stress scale factor on function 12.

Default = 1.0 (Real)

[ Pa ]
Fscale23r Residual shear yield stress scale factor on function 23.

Default = 1.0 (Real)

[ Pa ]
Fscale31r Residual shear yield stress scale factor on function 31.

Default = 1.0 (Real)

[ Pa ]
ε trans12r Transition strain in direction 12.

(Integer)

 
ε trans23r Transition strain in direction 23.

(Integer)

 
Transition strain in direction 31.

(Integer)

 
fct_ID21r Residual shear yield stress function in direction 21.

(Integer)

 
fct_ID32r Residual shear yield stress function in direction 32.

(Integer)

 
fct_ID13r Residual shear yield stress function in direction 13.

(Integer)

 
Fscale21r Residual shear yield stress scale factor on function 21.

Default = 1.0 (Real)

[ Pa ]
Fscale32r Residual shear yield stress scale factor on function 32.

Default = 1.0 (Real)

[ Pa ]
Fscale13r Residual shear yield stress scale factor on function 13.

Default = 1.0 (Real)

[ Pa ]

Example (Honeycomb)

#RADIOSS STARTER
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/UNIT/1
unit for mat
                  kg                  mm                  ms
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#-  2. MATERIALS:
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/MAT/LAW68/1/1
honeycomb
#              RHO_I
              3.2E-5                   0
#               E_11                E_22                E_33
                  40                  40                  80
#               G_12                G_23                G_31
                  15                  30                  30
# Initial tension/compression
#fun_ID11i fun_ID22i fun_ID33i    Iflag1           Fscale11i           Fscale22i           Fscale33i
        13        14        15         0                   1                   1                   1
# Tension/compression
#         Eps_max11i          Eps_max22i          Eps_max33i
                 .12                 .12                 .12
# Initial shear
#fun_ID12i fun_ID23i fun_ID31i    Iflag2           Fscale12i           Fscale23i           Fscale31i
        16        18        17         0                   1                   1                   1
# Shear
#         Eps_max12i          Eps_max23i          Eps_max31i
                 .14                 .14                 .14
# Initial shear
#fun_ID21i fun_ID32i fun_ID13i                     Fscale21i           Fscale32i           Fscale13i
        16        18        17                             0                   0                   0
# Residual tension/compression
#fun_ID11r fun_ID22i fun_ID33i                     Fscale11r           Fscale22r           Fscale33r
         3         4         5                             1                   1                   1
# Transition tension/compression
#       Eps_trans11r        Eps_trans22r        Eps_trans33r
                .022                .022                .022
# Residual shear
#fun_ID12r fun_ID23r fun_ID31r                     Fscale12r           Fscale23r           Fscale31r
         6         8         7                             1                   1                   1
# Transition shear
#       Eps_trans12r        Eps_trans23r        Eps_trans31r
                .041                .035                .035
# Residual shear
#fun_ID21r fun_ID32r fun_ID13r                     Fscale21r           Fscale32r           Fscale13r
         7         7         8                             0                   0                   0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#-  3. FUNCTIONS:
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/3
sig11
#                  X                   Y
                -100                  .4                                                            
                 100                  .4                                                            
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/4
sig22
#                  X                   Y
                -100                  .4                                                            
                 100                  .4                                                            
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/5
sig33
#                  X                   Y
                -100                  .8                                                            
                 100                  .8                                                            
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/6
sig12
#                  X                   Y
                -100                  .3                                                            
                 100                  .3                                                            
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/7
sig13
#                  X                   Y
                -100                  .5                                                            
                 100                  .5                                                            
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/8
sig23
#                  X                   Y
                -100                  .5                                                            
                 100                  .5                                                            
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/13
sig11
#                  X                   Y
                -100                  .4                                                            
               -.021                  .4                                                            
                -.02                  .8                                                            
                 .02                  .8                                                            
                .021                  .4                                                            
                 100                  .4                                                            
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/14
sig22
#                  X                   Y
                -100                  .4                                                            
               -.021                  .4                                                            
                -.02                  .8                                                            
                 .02                  .8                                                            
                .021                  .4                                                            
                 100                  .4                                                            
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/15
sig33
#                  X                   Y
                -100                  .8                                                            
               -.021                  .8                                                            
                -.02                 1.6                                                            
                 .02                 1.6                                                            
                .021                  .8                                                            
                 100                  .8                                                            
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/16
sig12
#                  X                   Y
                -100                  .3                                                            
               -.041                  .3                                                            
                -.04                  .6                                                            
                 .04                  .6                                                            
                .041                  .3                                                            
                 100                  .3                                                            
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/17
sig13
#                  X                   Y
                -100                  .5                                                            
               -.034                  .5                                                            
               -.033                   1                                                            
                .033                   1                                                            
                .034                  .5                                                            
                 100                  .5                                                            
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/18
sig23
#                  X                   Y
                -100                  .5                                                            
               -.034                  .5                                                            
               -.033                   1                                                            
                .033                   1                                                            
                .034                  .5                                                            
                 100                  .5                                                            
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#ENDDATA
/END
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

Comments

  1. This law is compatible with 8-node brick elements, under integrated elements and Isolid =1 or Isolid =2 only.
  2. When switching from a volumetric strain formulation to a strain formulation, Iflag = -1 allows the same function definition to be retained.
  3. If one of the failure or shear failure strains is reached, the element is deleted.
  4. Transition strains define transition from initial to residual yield stress function.
  5. If one of the transition or shear transition strains is reached, element has yield stress described by residual functions, in each direction. Transition is applied to the neighbor elements.