Engine Subroutine FnnLAW for Solid Elements
This subroutine calculates the criteria of failure model.
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 i^{th} user’s function
 DYDX
 Slope
 NPF, TF
 Private function parameters
Arguments
C
SUBROUTINE FnnLAW (
1 NEL ,NUPARAM ,NUVAR ,NFUNC ,IFUNC ,
2 NPF ,TF ,TIME ,TIMESTEP ,UPARAM ,
3 NGL ,NOT_USE_I1 ,NOT_USE_I2 ,NOT_USE_I3 ,NOT_USE_I4,
4 EPSPXX ,EPSPYY ,EPSPZZ ,EPSPXY ,EPSPYZ ,EPSPZX ,
5 EPSXX ,EPSYY ,EPSZZ ,EPSXY ,EPSYZ ,EPSZX ,
6 SIGNXX ,SIGNYY ,SIGNZZ ,SIGNXY ,SIGNYZ ,SIGNZX ,
7 PLA ,DPLA ,EPSP ,UVAR ,OFF ,
8 DELTAX, VOLN, UELR, NOT_USED4 ,NOT_USED5 )
C
Definitions
Argument  Format  Description 

NEL  Integer read only scalar  Number of elements per group. In the Engine subroutine, the element data are treated by groups for vectorization purposes. 
NUPARAM  Integer read only scalar  Size of user parameter array. 
NUVAR  Integer read only scalar  Number of user integration point element variables. 
NFUNC  Integer read only scalar  Number of functions used for failure model materials. 
IFUNC  Integer array read only  Array of size NFUNC containing function indexes. 
NPF  Integer array private data  Array used by FINTER (float external
functions). 
TF  Float array private data  Array used by FINTER (float external
functions). 
TIME  Float read only  Current time. 
TIMESTEP  Float read only  Current time step. 
UPARAM  Float array read only  User failure parameter array of size NUPARAM. 
NGL  Integer array read only  Array of size NEL containing the external element number. 
EPSPXX, EPSPYY, EPSPZZ, EPSPXY, EPSPYZ, ESPPZX  Float array read only  Array of size NEL containing strain rates in directions XX, YY, and ZZ and strain rates in directions XY, YZ, and ZX. 
EPSXX, EPSYY, EPSZZ, EPSXY, EPSYZ, EPSZX  Float array read only  Array of size NEL containing strain in directions XX, YY, and ZZ and strain rates in directions XY, YZ, and ZX. 
SIGNXX, SIGNYY, SIGNZZ, SIGNXY, SIGNYZ, SIGNZX  Float array read write  Array of size NEL containing stress in directions XX, YY, ZZ, XY, YZ, and ZX. 
PLA  Float array read only  Array of size NEL containing equivalent plastic strain. 
DPLA  Float array read only  Array of size NEL containing incremental equivalent plastic strain. 
EPSP  Float array read only  Array of size NEL, equivalent of strain rate. 
UVAR  Float array read write  Array of size NEL*NUVAR containing integration point element variables. 
OFF  Float array read write  Array of size NEL containing deleted
element flags.

DELTAX  Float array read only  Array of size NEL containing characteristic element length. 
VOLN  Float array read only  Array of size NEL containing current element volumes. 
UELR  Float array read write  Array of size NEL, containing the number of IP’s in which the failure criteria is satisfied for all elements. 
NOT_USE_I1, NOT_USE_I2, NOT_USE_I3, NOT_USE_I4  Integer scalar  Not used. Can be used in the future. 
NOT_USED4, NOT_USED5  Float scalar  Not used. Can be used in future. 