*HEADING
 : FLUID LINK TEST FOR SS ANALYSIS WITH F2D2
 (2-1x1x1 BLOCKS, PNEUMATIC FLUID)
*RESTART, WRITE, FREQ=1
*NODE, NSET=FLUID_CAVITY-1_NODES
  1, 0., 1.
  2, 1., 1.
  3, 1., 2.
  4, 0., 2.
*NODE, NSET=FLUID_CAVITY-2_NODES
 11, 0., 3.
 12, 1., 3.
 13, 1., 4.
 14, 0., 4.
*ELEMENT, TYPE=SFMAX1, ELSET=FLUID_CAVITY-1
 1, 2, 3
 2, 3, 4
*ELEMENT, TYPE=SFMAX1, ELSET=FLUID_CAVITY-2
 3, 12, 13
 4, 13, 14
*SURFACE SECTION, ELSET=FLUID_CAVITY-1
*SURFACE SECTION, ELSET=FLUID_CAVITY-2
*SURFACE,TYPE=ELEMENT,NAME=CAV1
 FLUID_CAVITY-1, SPOS
*SURFACE,TYPE=ELEMENT,NAME=CAV2
 FLUID_CAVITY-2, SPOS
**
**              MASS ELEMENTS
**
*ELEMENT, TYPE=MASS, ELSET=MASS1
 6, 4
*ELEMENT, TYPE=MASS, ELSET=MASS2
 7, 14
*MASS,ELSET=MASS1
 1.0, 
*MASS,ELSET=MASS2
 1.0E-6,
**
**              HYDROSTATIC FLUID PROPERTY
*PHYSICAL CONSTANTS, ABSOLUTE ZERO =-460, UNIVERSAL GAS CONSTANT=1.0
*FLUID CAVITY, NAME=CAVITY1, BEHAVIOR=FLUID, SURFACE=CAV1, REFNODE=1,AMBIENT PRESSURE=14.7
 1.0
*FLUID CAVITY, NAME=CAVITY2, BEHAVIOR=FLUID, SURFACE=CAV2, REFNODE=11,AMBIENT PRESSURE=14.7
 1.0
*FLUID BEHAVIOR, NAME=FLUID
*MOLECULAR WEIGHT
 449.0
**
*FLUID EXCHANGE, NAME=LINK, PROP=LINKBEHAVIOR
 1,11
*FLUID EXCHANGE PROPERTY, NAME=LINKBEHAVIOR, TYPE=BULK VISCOSITY
 10.0
**
**
**              SPRINGS
**
*ELEMENT, TYPE=SPRING1, ELSET=SPRINGY1
 21, 4
 41, 14
*SPRING, ELSET=SPRINGY1
 2, 
 1.E-8,
*BOUNDARY
 2,  1, 2, 0.0
 4,  1, 1, 0.0
 4,  3, 3, 0.0
 12, 1, 2, 0.0
 14, 1, 1, 0.0
 14, 3, 3, 0.0
*INITIAL CONDITIONS, TYPE=TEMPERATURE
 1, 200.
 11, 200.
*EQUATION
 2, 
 3, 1, 1.0
 2, 1,-1.0
 2, 
 3, 2, 1.0
 4, 2,-1.0
 2, 
 13, 1, 1.0, 12, 1, -1.0
 2, 
 13, 2, 1.0, 14, 2, -1.0
*NSET,NSET=out_pcav
1,
*NSET,NSET=out_ppor
1,11
**
**              STEP 1: STEADY STATE DYNAMICS
**                      WITH NO PRELOAD
**
*STEP
*STEADY STATE DYNAMICS,DIRECT
 0.1,
*CLOAD
4, 2, -10.
*NODE PRINT
 U,PCAV,PPOR,CVOL
 PU,
 V, A
*EL PRINT
 MFL,PHMFL
 MFLT,PHMFT
*OUTPUT, HISTORY
*ENERGYOUTPUT
*NODE OUTPUT,NSET=out_ppor
 U,POR,PCAV, V, A
*END STEP
**
**              STEP 1B: STEADY STATE DYNAMICS
**                       WITH NO PRELOAD 
**                       (NO IMAGINARY PART)
**
*STEP
*STEADY STATE DYNAMICS,DIRECT=REAL ONLY
 0.1,
*CLOAD
 4, 2, -10.
*NODE PRINT
 U,PCAV,PPOR,CVOL
 PU,
 V, A
*EL PRINT
 MFL,PHMFL
 MFLT,PHMFT
*OUTPUT, HISTORY
*ENERGYOUTPUT
*NODE OUTPUT,NSET=out_ppor
 U,POR,PCAV, V, A
*END STEP
**
**              STEP 2: PRELOAD
**
*STEP, NLGEOM
*STATIC
 .2, 1.
*CLOAD
 4, 2, -10.
 14, 2, -10.
*NODE PRINT
 U,PCAV,PPOR,CVOL
 PU,
 V, A
*EL PRINT
 MFL,PHMFL
 MFLT,PHMFT
*OUTPUT, HISTORY
*ENERGYOUTPUT
*NODE OUTPUT,NSET=out_ppor
 U,POR,PCAV, V, A
*END STEP
**
**              STEP 3: STEADY STATE DYNAMICS
**                      NO PRELOAD
**
*STEP
*STEADY STATE DYNAMICS,DIRECT
 0.1,
*CLOAD
 4, 2, -10.
*NODE PRINT
 U,PCAV,PPOR,CVOL
 PU,
 V, A
*EL PRINT
 MFL,PHMFL
 MFLT,PHMFT
*OUTPUT, HISTORY
*ENERGYOUTPUT
*NODE OUTPUT,NSET=out_ppor
 U,POR,PCAV, V, A
*END STEP
**
**              STEP 3B: STEADY STATE DYNAMICS
**                       WITH NO PRELOAD 
**                       (NO IMAGINARY PART)
**
*STEP
*STEADY STATE DYNAMICS,DIRECT=REAL ONLY
 0.1,
*CLOAD
 4, 2, -10.
*NODE PRINT
 U,PCAV,PPOR,CVOL
 PU,
 V, A
*EL PRINT
 MFL,PHMFL
 MFLT,PHMFT
*OUTPUT, HISTORY
*ENERGYOUTPUT
*NODE OUTPUT,NSET=out_ppor
 U,POR,PCAV, V, A
*END STEP