*HEADING
 : F3D3 FLUID ELEMENT TEST 
(1x1x1 BLOCK, HYDRAULIC, NO BULK MODULUS, NO THERMAL EXPANSION)
*RESTART, WRITE, FREQ=1
*NODE, NSET=CAV1NOD
  1, 1., 1., 1.
  2, 2., 1., 1.
  3, 2., 2., 1.
  4, 1., 2., 1.
  5, 1., 1., 0.
  6, 2., 1., 0.
  7, 2., 2., 0.
  8, 1., 2., 0.
*NSET,NSET=REFNODE
 1,
*ELEMENT,TYPE=SFM3D3,ELSET=STRUCTURE
 1, 2, 3, 6
 2, 3, 7, 6
 3, 7, 3, 4
 4, 4, 8, 7
 5, 6, 7, 8
 6, 5, 6, 8
*SURFACE SECTION, ELSET=STRUCTURE
*SURFACE,TYPE=ELEMENT,NAME=CAV1
 STRUCTURE, SPOS
*PHYSICAL CONSTANTS, ABSOLUTE ZERO = 0
*FLUID CAVITY, NAME=CAVITY1, BEHAVIOR=FLUID, SURFACE=CAV1, REFNODE=1
 1.0
*FLUID BEHAVIOR, NAME=FLUID
*FLUID DENSITY
 10.,  
*ELEMENT, TYPE=SPRING1, ELSET=SPRINGX1
21, 2
*SPRING, ELSET=SPRINGX1
1, 
400., 
*ELEMENT, TYPE=SPRING1, ELSET=SPRINGY1
42, 4
*SPRING, ELSET=SPRINGY1
2, 
1.E-6,
*BOUNDARY
2, 2, 3, 0.0
3, 2, 3, 0.0
4, 1, 1, 0.0
4, 3, 3, 0.0
5, 1, 3, 0.0
6, 2, 3, 0.0
7, 3, 3, 0.0
8, 1, 1, 0.0
8, 3, 3, 0.0
*EQUATION
2, 
3, 1, 1.0, 2, 1, -1.0
2, 
6, 1, 1.0, 2, 1, -1.0
2, 
7, 1, 1.0, 2, 1, -1.0
2, 
3, 2, 1.0, 4, 2, -1.0
2, 
7, 2, 1.0, 4, 2, -1.0
2, 
8, 2, 1.0, 4, 2, -1.0
*STEP, NLGEOM
*STATIC
.2, 1.
*CLOAD
4, 2, -600.
*NODE PRINT,FREQ=100
U,PCAV,CVOL
*OUTPUT,FIELD,FREQ=100
*NODE OUTPUT
U,
*OUTPUT,HISTORY
*NODE OUTPUT, NSET=REFNODE
PCAV,CVOL
*OUTPUT,HISTORY,FREQUENCY=1
*ENERGY OUTPUT,VARIABLE=PRESELECT
*ENERGY PRINT
*END STEP