*HEADING
 STATIC INDENTATION OF A VISCOELASTIC,ELASTOMERIC FOAM 
 WITH A HEMISPHERICAL PUNCH AND CAX4R ELEMENTS WITH ENHANCED HOURGLASS CONTROL
********************************************************
** Measure the punch reaction force during the following 2 steps:
**     Step 1: Displace punch 250 mm downwards.
**     Step 2: Return punch to original position.
**             (Units: N, mm, sec)
********************************************************
*PREPRINT,MODEL=YES,HISTORY=NO
*RESTART,WRITE
*NODE
   1,   0., 300.
  19,   0.,   0.
 481, 300., 300.
 499, 300.,   0.
 601, 600., 300.
 619, 600.,   0.
*NSET,NSET=N1
 1, 
*NSET,NSET=N19
 19, 
*NSET,NSET=N481
 481, 
*NSET,NSET=N499
 499, 
*NFILL,NSET=TOP,BIAS=.85
 N1,N481,12,40
*NGEN,NSET=TOP
 481,601,40
*NFILL,NSET=BOT,BIAS=.85
 N19,N499,12,40
*NGEN,NSET=BOT
 499,619,40
*NFILL,NSET=ALLN,BIAS=.9
 TOP,BOT,9,2
*NSET,NSET=CENTER,GENERATE
 1,19
*ELEMENT,TYPE=CAX4R
 1,3,43,41,1
*ELGEN,ELSET=FOAM
 1,15,40,10,9,2,1
*ELSET,ELSET=CENT,GENERATE
 1,141,10
 61,69
*ELSET,ELSET=ETOP,GENERATE
 1,101,10
*ELSET,ELSET=UPPER,GEN
 1,141,10
*NODE,NSET=PUNCH
 1000,0.,510.
*SOLID SECTION,ELSET=FOAM,MATERIAL=FOAM,ORIENTATION=RECT
*ORIENTATION,NAME=RECT,SYSTEM=RECTANGULAR
 1.,0.,0., 0.,1.,0.
 3,0.
****************************************************
*MATERIAL,NAME=FOAM
*HYPERFOAM,N=2,TEST DATA INPUT,POISSON=0.0,MODULI=INSTANTANEOUS
*UNIAXIAL TEST DATA
 -.0217,   -.05
 -.0317,   -.10
 -.0367,   -.15
 -.0402,   -.20
 -.0433,   -.25
 -.0467,   -.30
 -.0504,   -.35
 -.0542,   -.40
 -.0604,   -.45
 -.0668,   -.50
 -.0759,   -.55
 -.0909,   -.60
 -.1083,   -.65
 -.1410,   -.70
 -.1933,   -.75
 -.2896,   -.80
*SIMPLE SHEAR TEST DATA      
  .0140, .08, .0046
  .0334, .16, .0166
  .0533, .24, .0366
  .0853, .32, .0573
  .1280, .40, .0817
  .1653, .48, .1098
  .2080, .56, .1394
  .2560, .64, .1666
  .2987, .72, .1904
*VISCOELASTIC,TIME=RELAXATION TEST DATA
*SHEAR TEST DATA,SHRINF=0.5000
 1.0000, 0.0001
 0.9695, 0.001
 0.9417, 0.002
 0.8722, 0.005
 0.7913, 0.010
 0.7043, 0.020
 0.6233, 0.050
 0.5736, 0.100
 0.5271, 0.200
 0.5013, 0.500
 0.5000, 1.000
*DENSITY
 1.E-11,
****************************************************
*BOUNDARY
 BOT,1,2     
 CENTER,1
 1000,1
 1000,6
****************************************************
*SURFACE,TYPE=SEGMENTS,NAME=IMPACTOR
 START,141.42,641.42
 CIRCL,-1.,300.,0.,500.
*SURFACE,TYPE=ELEMENT,NAME=TARGET
 ETOP,S3
*RIGID BODY,REF NODE=1000,ANALYTICAL SURFACE=IMPACTOR
*CONTACT PAIR,INTERACTION=ROUGH
 TARGET,IMPACTOR
*SURFACE INTERACTION,NAME=ROUGH
*FRICTION
 0.8, 
****************************************************
*STEP,NLGEOM,INC=200,AMPLITUDE=RAMP,UNSYMM=YES
 Displace punch 250 mm downwards.
*VISCO,CETOL=0.01
 .0015,1.,,.05
*BOUNDARY
 1000,2,2,-250.
*PRINT,CONTACT=YES
*CONTACT PRINT,SECONDARY=TARGET
**CONTACT FILE,SECONDARY=TARGET,FREQUENCY=10
*ENERGY PRINT,FREQUENCY=5
*ENERGY PRINT,ELSET=FOAM,FREQ=5
*ENERGY PRINT,ELSET=CENT,FREQ=5
*EL PRINT,FREQUENCY=50,ELSET=CENT   
 S, 
 E,  
*NODE PRINT,FREQUENCY=25
 U,
 RF,
*OUTPUT,FIELD,FREQUENCY=4
*NODE OUTPUT
 U,V,A,RF
*ELEMENT OUTPUT
 S,LE,NE
*CONTACT OUTPUT,VARIABLE=PRESELECT,NSET=TOP
*OUTPUT,HISTORY,FREQUENCY=1
*NODE OUTPUT,NSET=PUNCH
 U,V,A,RF
*ELEMENT OUTPUT,ELSET=CENT
 S,LE,NE
*ENERGY OUTPUT,VARIABLE=PRESELECT
*END STEP
****************************************************
*STEP,NLGEOM,INC=200,AMPLITUDE=RAMP,UNSYMM=YES
 Return punch to original position.
*VISCO,CETOL=0.01
.0015,1.,,.05
*BOUNDARY,OP=MOD
 1000,2,2,0.0
*OUTPUT,FIELD,FREQUENCY=4
*NODE OUTPUT
 U,V,A,RF
*ELEMENT OUTPUT
 S,LE,NE
*CONTACT OUTPUT,VARIABLE=PRESELECT,NSET=TOP
*OUTPUT,HISTORY,FREQUENCY=1
*NODE OUTPUT,NSET=PUNCH
 U,V,A,RF
*ELEMENT OUTPUT,ELSET=CENT
 S,LE,NE
*ENERGY OUTPUT,VARIABLE=PRESELECT
*END STEP