/MAT/LAW68 (COSSER)

Block Format Keyword This law describes the honeycomb material.

Format

(1)	(2)	(3)	(4)	(5)	(7)	(9)
/MAT/LAW68/`mat_ID`/`unit_ID` or /MAT/COSSER/`mat_ID`/`unit_ID`
`mat_title`
$ρ_{i}$
`E`₁₁		`E`₂₂		`E`₃₃
`G`₁₂		`G`₂₃		`G`₃₁
`fct_ID`_11i	`fct_ID`_22i	`fct_ID`_33i	`Iflag`₁	`Fscale`_11i	`Fscale`_22i	`Fscale`_33i
$ε_{\max 11 i}$		$ε_{\max 22 i}$		$ε_{\max 33 i}$
`fct_ID`_12i	`fct_ID`_23i	`fct_ID`_31i	`Iflag`₂	`Fscale`_12i	`Fscale`_23i	`Fscale`_31i
$ε_{\max 12 i}$		$ε_{\max 23 i}$		$ε_{\max 31 i}$
`fct_ID`_21i	`fct_ID`_32i	`fct_ID`_13i		`Fscale`_21i	`Fscale`_32i	`Fscale`_13i
`fct_ID`_11r	`fct_ID`_22r	`fct_ID`_33r		`Fscale`_11r	`Fscale`_22r	`Fscale`_33r
$ε_{t r a n s 11 r}$		$ε_{t r a n s 22 r}$		$ε_{t r a n s 33 r}$
`fct_ID`_12r	`fct_ID`_23r	`fct_ID`_31r		`Fscale`_12r	`Fscale`_23r	`Fscale`_31r
$ε_{t r a n s 12 r}$		$ε_{t r a n s 23 r}$		$ε_{t r a n s 31 r}$
`fct_ID`_21r	`fct_ID`_32r	`fct_ID`_13r		`Fscale`_21r	`Fscale`_32r	`Fscale`_13r

Definitions

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)	$[\frac{kg}{m^{3}}]$
`E`₁₁	Young's modulus (Real)	$[Pa]$
`E`₂₂	Young's modulus (Real)	$[Pa]$
`E`₃₃	Young's modulus (Real)	$[Pa]$
`G`₁₂	Shear modulus (Real)	$[Pa]$
`G`₂₃	Shear modulus (Real)	$[Pa]$
`G`₃₁	Shear modulus (Real)	$[Pa]$
`fct_ID`_11i	Initial yield stress function identifier in direction 11. (Integer)
`fct_ID`_22i	Initial yield stress function identifier in direction 22. (Integer)
`fct_ID`_33i	Initial yield stress function identifier in direction 33. (Integer)
`Iflag`₁	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)
`Fscale`_11i	Initial yield stress scale factor on function 11. Default = 1.0 (Real)	$[Pa]$
`Fscale`_22i	Initial yield stress scale factor on function 22. Default = 1.0 (Real)	$[Pa]$
`Fscale`_33i	Initial yield stress scale factor on function 33. Default = 1.0 (Real)	$[Pa]$
$ε_{\max 11 i}$	Initial failure strain in tension in direction 1. (Real)
$ε_{\max 22 i}$	Initial failure strain in tension in direction 2. (Real)
$ε_{\max 33 i}$	Initial failure strain in tension in direction 3. (Real)
`fct_ID`_12i	Initial shear yield stress function in direction 12. (Integer)
`fct_ID`_23i	Initial shear yield stress function in direction 23. (Integer)
`fct_ID`_31i	Initial shear yield stress function in direction 31. (Integer)
`Iflag`₂	Strain formulation for shear yield functions 12, 23, and 31. (Integer)
`Fscale`_12i	Initial shear yield stress scale factor on function 12. Default = 1.0 (Real)	$[Pa]$
`Fscale`_23i	Initial shear yield stress scale factor on function 23. Default = 1.0 (Real)	$[Pa]$
`Fscale`_31i	Initial shear yield stress scale factor on function 31. Default = 1.0 (Real)	$[Pa]$
$ε_{\max 12 i}$	Initial failure strain in direction 12. (Integer)
$ε_{\max 23 i}$	Initial failure strain in direction 23. (Integer)
$ε_{\max 31 i}$	Initial failure strain in direction 31. (Integer)
`fct_ID`_21i	Initial shear yield stress function in direction 21. (Integer)
`fct_ID`_32i	Initial shear yield stress function in direction 32. (Integer)
`fct_ID`_13i	Initial shear yield stress function in direction 13. (Integer)
`Fscale`_21i	Initial shear yield stress scale factor on function 21. Default = 1.0 (Real)	$[Pa]$
`Fscale`_32i	Initial shear yield stress scale factor on function 32. Default = 1.0 (Real)	$[Pa]$
`Fscale`_13i	Initial shear yield stress scale factor on function 13. Default = 1.0 (Real)	$[Pa]$
`fct_ID`_11r	Residual yield stress function in direction 11. (Integer)
`fct_ID`_22r	Residual yield stress function in direction 22. (Integer)
`fct_ID`_33r	Residual yield stress function in direction 33. (Integer)
`Fscale`_11r	Residual yield stress scale factor on function 11. Default = 1.0 (Real)	$[Pa]$
`Fscale`_22r	Residual yield stress scale factor on function 22. Default = 1.0 (Real)	$[Pa]$
`Fscale`_33r	Residual yield stress scale factor on function 33. Default = 1.0 (Real)	$[Pa]$
$ε_{t r a n s 11 r}$	Transition strain in direction 11. (Real)
$ε_{t r a n s 22 r}$	Transition strain in direction 22. (Real)
$ε_{t r a n s 33 r}$	Transition strain in direction 33. (Real)
`fct_ID`_12r	Residual shear yield stress function in direction 12. (Integer)
`fct_ID`_23r	Residual shear yield stress function in direction 23. (Integer)
`fct_ID`_31r	Residual shear yield stress function in direction 31. (Integer)
`Fscale`_12r	Residual shear yield stress scale factor on function 12. Default = 1.0 (Real)	$[Pa]$
`Fscale`_23r	Residual shear yield stress scale factor on function 23. Default = 1.0 (Real)	$[Pa]$
`Fscale`_31r	Residual shear yield stress scale factor on function 31. Default = 1.0 (Real)	$[Pa]$
$ε_{t r a n s 12 r}$	Transition strain in direction 12. (Integer)
$ε_{t r a n s 23 r}$	Transition strain in direction 23. (Integer)
	Transition strain in direction 31. (Integer)
`fct_ID`_21r	Residual shear yield stress function in direction 21. (Integer)
`fct_ID`_32r	Residual shear yield stress function in direction 32. (Integer)
`fct_ID`_13r	Residual shear yield stress function in direction 13. (Integer)
`Fscale`_21r	Residual shear yield stress scale factor on function 21. Default = 1.0 (Real)	$[Pa]$
`Fscale`_32r	Residual shear yield stress scale factor on function 32. Default = 1.0 (Real)	$[Pa]$
`Fscale`_13r	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

This law is compatible with 8-node brick elements, under integrated elements and I_solid =1 or I_solid =2 only.
When switching from a volumetric strain formulation to a strain formulation, I_flag = -1 allows the same function definition to be retained.
If one of the failure or shear failure strains is reached, the element is deleted.
Transition strains define transition from initial to residual yield stress function.
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.