CFVR8006 - Cam-clay material

Triaxial test of a Cam-clay material. 3D case

Conventional triaxial test of a hexaedral specimen
References: [1] "Inelastic Analysis of Solids and Structures", M. Kojic y K.J. Bathe. Example 6.3.1: Conventonal triaxial test of Cam-Clay material [2] "Constitutive Laws for Engineering Materials", C.S. Desai y Siriwardane. Example 11-4: Critical state model for laboratory specimen
Notes:

Conventional criterion of signs used in geotechnics has been followed: compressions and shortenings => positive tractions and stretchings => negative
Target values for kinematic quantities are computed from the numerically obtained using different formulas to those used for the numerical ones

Element types used in the model: SOLID185

Needed CivilFEM Modules:
Geotechnical Module
Bridges and Civil Non Linearities Module
Advanced Prestressed Concrete Module

The example can be launched on an educational license.

KEYWORDS

Materials

Geotechnics

Material Models

Model Statistics
Number of elements	1
Number of nodes	8
Number of civil materials	1
Number of cross sections	0
Number of shell vertices	0

Log file: CFVR8006.DAT

  FINISH
  ~CFCLEAR,,1
  NomFile='CFVR8006'
  /TITLE, %NomFile%, Cam-clay material

! -------------------------------------------------------------------------------------
! Initial data
! -------------------------------------------------------------------------------------
  ~UNITS,SI
  /PREP7

  M      = 1.0      ! slope of the critical state line (CSL) in q-log(p) plane
  LAM    = 0.14     ! slope of the isotropic consolidation line
  KAP    = 0.026    ! slope of the unloading-reloading line
  VOID0  = 1.08     ! initial void ratio
  P0     = 114.E+3  ! initial preconsolidation ratio
  E0     = 9900.E+3 ! initial Young's modulus
  NU     = 0.3      ! initial Poisson's ratio
  SIG0   = 100.E+3  ! initial stresses
  SIGYMX = 2.4*SIG0 ! máximum value of the axial stress
  NTSTP  = 200      ! number of substeps

! -------------------------------------------------------------------------------------
! Model definition
! -------------------------------------------------------------------------------------
  ! Materials

  ~CFMP,1,LIB,SOIL ,,CL
  ~CFMP,1,SOIL,KPLA,,3
  ~CFMP,1,SOIL,KP0,,1
  ~CFMP,1,SOIL,M,,M
  ~CFMP,1,SOIL,LAM,,LAM
  ~CFMP,1,SOIL,KAP,,KAP
  TMP = 1. + VOID0 + LAM*LOG(P0)+ KAP*LOG(SIG0/P0)
  ~CFMP,1,SOIL,VICL,,TMP
  ~CFMP,1,SOIL,P0,,P0
  ~CFMP,1,SOIL,EXst,,E0
  ~CFMP,1,SOIL,NUXYst,,NU

  ! Element types

  ET,1,SOLID185

  ! Meshing

  N,1,0.,0.,0.
  N,2,1.,0.,0.
  N,3,1.,1.,0.
  N,4,0.,1.,0.
  N,5,0.,0.,1.
  N,6,1.,0.,1.
  N,7,1.,1.,1.
  N,8,0.,1.,1.
  E,1,2,3,4,5,6,7,8

  ! Loads

  D,1,ALL
  D,2,UY,,,,,UZ
  D,3,UZ
  D,4,UX,,,,,UZ
  D,5,UX,,,,,UY
  D,6,UY
  D,8,UX

  *DIM,FS1,TABLE,2,,,TIME
  *DIM,FS2,TABLE,2,,,TIME
  FS1(1,0) = 0.,1.
  FS1(1,1) = SIG0,SIG0
  FS2(1,0) = 0.,1.
  FS2(1,1) = SIG0,SIGYMX
  SFE,1,3,PRES,,%FS1%
  SFE,1,6,PRES,,%FS1%
  SFE,1,4,PRES,,%FS2%

  INISTATE,SET,DTYP,STRE
  INISTATE,DEFINE,1,,,,-SIG0,-SIG0,-SIG0,0.,0.,0.

!--------------------------------------------------------------------------------------
! DATA CHECK
!--------------------------------------------------------------------------------------
! Data comparison number
  NCOMP    = 5
  NCOMP_CH = 0

! Array dimensions
  *DIM,LABEL,CHAR,NCOMP,1
  *DIM,LABEL_CH,CHAR,NCOMP_CH,1
  *DIM,VALUE,,NCOMP,3
  *DIM,VALUE_CH,CHAR,NCOMP_CH,3
  *DIM,TOLER,,NCOMP,2

! Labels
!--------------------------------------------------------------------------------------
  LABEL(1) = 'SX'
  LABEL(2) = 'SY'
  LABEL(3) = 'EPVEL' ! elastic volumetric strain
  LABEL(4) = 'EPVPL' ! plastic volumetric strain
  LABEL(5) = 'VOL'   ! specific volume

 ! Resolution
 !--------------------------------------------------------------------------------------
  /SOLU

  NLGEOM,OFF
  AUTOTS,OFF
  NROPT,UNSYM
  LNSRCH,ON
  ! NEQIT,50 Se comenta pues en la version 2019r1 se da una ostia ansys cuando se especifica el numero de iteraciones y existen variables de estado
  CUTCONTROL,PLSLIMIT,5.

  ERESX,NO
  OUTRES,NSOL,1
  OUTRES,ESOL,1
  OUTRES,SVAR,1

  TIME,1.
  NSUBST,NTSTP
  SOLVE

  /POST26

  NUMVAR,25

  ESOL,2,1,1,S,Y
  ADD,2,2,,,,,,-1.
  ESOL,3,1,1,S,X
  ADD,3,3,,,,,,-1.
  ESOL,4,1,1,EPEL,Y
  ESOL,5,1,1,EPPL,Y
  ESOL,6,1,1,EPEL,X
  ESOL,7,1,1,EPPL,X
  ADD,10,4,6,,,,,-1.,-2.
  ADD,11,5,7,,,,,-1.,-2.
  ADD,12,2,3,,,,,1/3,2/3
  ESOL,13,1,1,SVAR,1
  ESOL,14,1,1,SVAR,6

  VGET,WRK1,10
  VGET,WRK2,12
  VGET,WRK3,14
  *VOPER,WRK4,KAP,DIV,WRK2
  *VOPER,WRK4,WRK4,DIV,WRK3
  *VOPER,WRK4,WRK4,INT1,WRK2,WRK1(1)
  VPUT,WRK4,15

  VGET,WRK1,11
  VGET,WRK2,13
  VGET,WRK3,14
  TMP = LAM-KAP
  *VOPER,WRK4,TMP,DIV,WRK2
  *VOPER,WRK4,WRK4,DIV,WRK3
  *VOPER,WRK4,WRK4,INT1,WRK2,WRK1(1)
  VPUT,WRK4,16

  VGET,WRK1,13
  TMP = WRK1(1)
  *VOPER,WRK1,WRK1,DIV,TMP
  *VFUN,WRK1,LOG,WRK1
  TMP = -LAM
  *VOPER,WRK1,TMP,MULT,WRK1
  VGET,WRK2,14
  TMP = WRK2(1)
  *VOPER,WRK1,TMP,ADD,WRK1
  VPUT,WRK1,17

! Correct values
!--------------------------------------------------------------------------------------
  VALUE(1,1) = SIG0
  VALUE(2,1) = SIGYMX
  VGET,WRK,15
  VALUE(3,1) = WRK(NTSTP)
  VGET,WRK,16
  VALUE(4,1) = WRK(NTSTP)
  VGET,WRK,17
  VALUE(5,1) = WRK(NTSTP)

! Obtained values
!--------------------------------------------------------------------------------------
  VGET,WRK,3
  VALUE(1,2) = WRK(NTSTP)
  VGET,WRK,2
  VALUE(2,2) = WRK(NTSTP)
  VGET,WRK,10
  VALUE(3,2) = WRK(NTSTP)
  VGET,WRK,11
  VALUE(4,2) = WRK(NTSTP)
  VGET,WRK,14
  VALUE(5,2) = WRK(NTSTP)

! Warning and error tolerances
  EPS = 9.E-03
  EPS1 = 9.E-03
  TOLER(1,1) = EPS*ABS(VALUE(1,1)) $ TOLER(1,2) = TOLER(1,1)
  TOLER(2,1) = EPS*ABS(VALUE(2,1)) $ TOLER(2,2) = TOLER(2,1)
  TOLER(3,1) = EPS*ABS(VALUE(3,1)) $ TOLER(3,2) = TOLER(3,1)
  TOLER(4,1) = EPS*ABS(VALUE(4,1)) $ TOLER(4,2) = TOLER(4,1)
  TOLER(5,1) = EPS1*ABS(VALUE(5,1)) $ TOLER(5,2) = TOLER(5,1)

!--------------------------------------------------------------------------------------
! Results comparison
!--------------------------------------------------------------------------------------
!  TMP = $ WRK1 = $ WRK2 = $ WRK3 = $ WRK4 =
  COMPARA.MAC

Results

Label	Target	CivilFEM	Ratio	Tolerance
SX	1e+005	1e+005	1.000	900
SY	2.4e+005	2.4e+005	1.000	2160
EPVEL	0.0048926	0.0048966	0.999	4.403e-005
EPVPL	0.050723	0.050731	1.000	0.0004565
VOL	1.954	1.9675	0.993	0.01759

Contains proprietary and confidential information of Ingeciber, S.A.

CivilFEM Online Help

CFVR8006 - Cam-clay material

Triaxial test of a Cam-clay material. 3D case

Results