Engine Subroutine LUSERnn for Solid Elements
This subroutine calculates the stress tenor versus the strain tensor, strain rate tensor, density, volume, internal energy, or user variables.
Arguments
LUSERnn
and its individual arguments and
descriptions
are:C---------------------------------------------------------------------------
SUBROUTINE LUSERnn (
1 NEL ,NUPARAM,NUVAR ,NFUNC ,IFUNC ,NPF ,
2 TF ,TIME ,TIMESTEP,UPARAM ,RHO , VOLUME ,
3 EINT , NGL, SOUNDSP,VISCMAX,UVAR ,OFF ,
4 SIGY , PLA , USERBUF )
C---------------------------------------------------------------------------
- With isotropic mode, the directions XX, YY, ... are the global reference
frame axis. The old elastoplastic stresses (arrays
SIGOXX
,SIGOYY
, ...) are already rotated to take into account the rigid body rotation. - With orthotropic mode, the directions are the orthotropic frame axis.
- With connection element (/PROP/TYPE43), only directions ZZ,ZX, and YZ have to be defined.
FINTER
(shown
below) to get the value Y of the function for the abscissa
X.Y=FINTER(IFUNC(I),X,NPF,TF,DYDX)
- Variable
- Description
- Y
- Interpolated value
- X
- Abscissa value of the function
- I
- The ith user’s function
- DYDX
- Slope
- NPF, TF
- Private function parameters
The SOUNDSP
array is used in the calculation of the stability time
step, the hourglass forces, and the artificial viscous pressure Q.
For isotropic materials, the sound speed value should be equal to the plane wave speed.
- Variable
- Description
- K
- Bulk modulus
- G
- Shear modulus
- and
- Lame parameters
Use VISCMAX
to calculate the time step stability when the material
law formulation is viscous.
Definitions
Argument | Format | Description |
---|---|---|
NEL |
Integer read only scalar | Number of elements per group. In Radioss Engine subroutines, the element data are treated by groups for vectorization. This argument is machine-dependent and set by Radioss. |
NUPARAM |
Integer read only scalar | Size of the user parameter array. |
NUVAR |
Integer read only scalar | Number of user element variables. |
NFUNC |
Integer read only scalar | Number of functions used for material law. |
IFUNC |
Integer array read only | Array of size NFUNC with function
indexes. |
NPF |
Integer array private data | Array used by FINTER (float external
function). |
TF |
Integer array private data | Array used by FINTER (float external
function). |
TIME |
Float read only | Current time. |
TIMESTEP |
Float read only | Current time step. |
UPARAM |
Float array read only | User material parameter array of size
NUPARAM . |
RHO |
Float array read only | Array of size NEL containing current
densities. |
VOLUME |
Float array read only | Array of size NEL containing current element
volumes. |
EINT |
Float array read only | Array of size NEL containing total internal
energy. |
SOUNDSP |
Float array write only | Array of size NEL containing sound
speed. |
VISCMAX |
Float array write only | Array of size NEL containing the maximum
damping modulus. |
UVAR |
Float array read write | Array of size NEL *NUVAR
containing user element variables. |
OFF |
Float array read write | Array of size NEL containing deleted element flags.
|
USERBUF |
Data structure read write | Defined in LAW_USERSO.mod. This module
is used inside LUSERnn . |
USERBUF
data structure contains:
Argument | Format | Description |
---|---|---|
ID |
Integer read only scalar | Material ID defined in Starter input
deck. |
NCYCLE |
Integer read only | Cycle number. First cycle is equal to 0. |
IPTR |
Integer read only | Integration point (direction r). |
IPTS |
Integer read only | Integration point (direction s). |
IPTT |
Integer read only | Integration point (direction t). |
EPSPXX , EPSPYY ,
EPSPZZ , EPSPXY ,
EPSPYZ , EPSPZX |
Float array read only | Arrays of size NEL containing
strain rates in directions XX, YY, and
ZZ and strain rates in directions XY, YZ,
ZX. |
DEPSXX , DEPSYY ,
DEPSZZ , DEPSXY ,
DEPSYZ , DEPSZX |
Float array read only | Arrays of size NEL containing
strain increments in directions XX, YY,
and ZZ and strain increments in directions XY, YZ,
and ZX. |
EPSXX , EPSYY ,
EPSZZ , EPSXY ,
EPSYZ , EPSZX |
Float array read only | Array of size NEL containing
strains in directions XX, YY, and ZZ
and strains in directions XY, YZ, and
ZX. |
SIGOXX , SIGOYY ,
SIGOZZ , SIGOXY ,
SIGOYZ , SIGOZX |
Float array read only | Array of size NEL with old (previous time
step) elastoplastic stresses in directions XX, YY, ZZ, XY, YZ,
and ZX. |
FPSXX , FPSYY ,
FPSZZ , FPSXY ,
FPSYX , FPSXZ ,
FPSZX , FPSYZ ,
FPSZY |
Float array ready only | Array of size NEL containing the deformation
gradient tensor. |
UPSXX , UPSYY ,
UPSZZ , UPSXY ,
UPSYZ , UPSXZ |
Float array ready only | Array of size NEL containing the stretch
tensor. |
R11 , R12 ,
R13 , R21 ,
R22 , R23 ,
R31 , R32 ,
R33 |
Float array write only | Array of size NEL containing rotation
matrices from the global skew system to an element skew
system. |
SIGNXX , SIGNYY ,
SIGNZZ , SIGNXY ,
SIGNYZ , SIGNZX |
Float array write only | Array of size NEL with new computed
elastoplastic stresses in directions XX, YY, ZZ, XY, YZ, and
ZX. |
SIGVXX , SIGVYY ,
SIGVZZ , SIGVXY ,
SIGVYZ , SIGVZX |
Float array write only | Array of size NEL containing viscous
stresses in directions XX, YY, ZZ, XY, YZ, and ZX. |
RHO0 |
Float array read only | Array of size NEL containing initial
densities. |
DPLA |
Float array write only | Array of size NEL containing incremental
plastic strain. |
TEMP |
Float array read only | Array of size NEL containing
temperature. |
Data Necessary for HEPH Compatibility
Definitions
Argument | Format | Description |
---|---|---|
PLA |
Float array write only | Array of size NEL containing plastic
strain. |
SIGY |
Float array read only | Array of size NEL containing yield
stress. |