*HEADING
AIRSPRING -- AXISYMMETRIC MODEL
*NODE
1,    0.       , 2.E-2
4,    20.E-2   , 2.E-2
6,    20.E-2   , 0.
26,   40.E-2   , 0.
32,   37.771E-2, 6.293E-2
38,   36.211E-2, 10.698E-2
39,   36.211E-2, 11.35E-2
40,   36.211E-2, 12.E-2
500,  0.       , 9.E-2
1000, 0.       , 12.E-2
*NSET, NSET = CAVITY
500, 
*NGEN, LINE = C
6,  26, 2, , 30.E-2   , 0.       , 0., 0., 0., 1.
26, 32, 1, , 30.E-2   , 0.       , 0.
32, 38, 1, , 43.211E-2, 10.698E-2, 0.
**
** RUBBER SPRING
**
*ELEMENT, TYPE = SAX1
2,   4, 6
26, 26, 27
*ELGEN, ELSET = SPRING
2,  11, 2, 2
26, 14, 1, 1
*SHELL SECTION, COMPOSITE, ELSET = SPRING
2.5E-3, 3, RUBBER
1.0E-3, 3, STEEL
2.5E-3, 3, RUBBER
*MATERIAL, NAME = RUBBER
*HYPERELASTIC, POLYNOMIAL, N = 1
3.2E6, 0.8E6
*DENSITY
1000., 
*MATERIAL, NAME = STEEL
*ELASTIC, TYPE=LAMINA
2.48E9, 2.86E7, 9.105, 8.0E6, 8.0E6, 8.0E6
*DENSITY
7.8E3, 
**
** RIGID BODY/SURFACE
**
*NODE, NSET = RIGID
11000, 0.       , 12.E-2
*NODE,NSET=RIGNODE
11001, 36.211E-2, 10.698E-2
11021, 41.711E-2,  5.198E-2
12000, 41.711E-2, 10.698E-2
*NGEN,NSET=RIGNODE,LINE=C
11001, 11021, 1, 12000
*ELEMENT,TYPE=RAX2,ELSET=RIGELEM
11001, 1000,40
11002, 40, 11002
11003, 11002, 11003
*ELGEN,ELSET=RIGELEM
11003, 19, 1, 1
*ELEMENT,TYPE=MASS,ELSET=MASS_RIGID
11000, 11000
*MASS,ELSET=MASS_RIGID
.5, 
*ELEMENT, TYPE = SAX1, ELSET = FLUID
201,  1,  4
299, 40, 1000
*SHELL SECTION, ELSET=FLUID, MATERIAL=A1
1E-3, 
*MATERIAL,NAME=A1
*ELASTIC
1E5, 0.1
*DENSITY
1.E-4,  
*ELSET, ELSET=SPRINGSURF
   2,   4,   6,   8,  10,  12,  14,  16,  18,  20,  22,  26,  27,  28,  29,  30
  31,  32,  33,  34,  35,  36,  37,  38,  39, 201, 299
*SURFACE, TYPE=ELEMENT, NAME=CAVSURF
SPRINGSURF, SPOS
*PHYSICAL CONSTANTS, ABSOLUTE ZERO=-273.16, UNIVERSAL GAS CONSTANT=8.314
**
**FLUID CAVITY DEFINITON
**
*FLUID CAVITY, NAME=SPRINGCAV, BEHAVIOR=GAS, REF NODE=500, SURFACE=CAVSURF, AMBIENT PRESSURE=101.36E+3

*FLUID BEHAVIOR, NAME=GAS
*MOLECULAR WEIGHT
0.044
*CAPACITY, TYPE=TABULAR
30
**
*BOUNDARY
1,1,3
4,1,6
6,1,1
RIGID,1,6
*NSET,NSET=RIG
40,1000
*AMPLITUDE,NAME=RAMP,DEFINITION=SMOOTHSTEP
0.,0.,  .05,1.0
*NSET, NSET=QA_TEST_CAVITY
CAVITY,
*NSET, NSET=QA_TEST_RIGID
RIGID,
*SURFACE,TYPE=ELEMENT,NAME=ASURF,NOTHICK
ECON,SNEG
*SURFACE,TYPE=ELEMENT,NAME=BSURF
RIGELEM,SNEG
*RIGID BODY,REFNODE=11000,ELSET=RIGELEM
**
** STEP 1 - INFLATION STEP (5 ATMOSPHERES)
**
*STEP
*DYNAMIC,EXPLICIT, fixed
,.045
*RESTART,WRITE,NUMBER INTERVAL=1
*BOUNDARY,AMPLITUDE=RAMP
CAVITY,8,8, 5.066E5
**
** CONTACT DEFINITION
**
*ELSET,ELSET=ECON,GENERATE
26,38,1         
*CONTACT PAIR,INTERACTION=SMOOTH
ASURF,BSURF
*SURFACE INTERACTION,NAME=SMOOTH
**
** OUTPUT REQUESTS
**
*ELSET,ELSET=EOUT
39, 
*OUTPUT, FIELD, TIME MARKS=YES, NUMBER INTER=2
*NODE OUTPUT, NSET=QA_TEST_RIGID
u
**RF,
*OUTPUT, HIST, FREQ=1
*incrementation output
DT,
*ENERGY OUTPUT, VAR=all
***OUTPUT, HIST, FREQ=9999
***NODE OUTPUT, NSET=QA_TEST_CAVITY
** por
**PCAV, CVOL
***ENERGY OUTPUT, VAR=PRESELECT
***OUTPUT, FIELD, TIM E MARKS=YES, NUMBER INTER=4
***NODE OUTPUT, NSET=QA_TEST_RIGID
**U,
*DLOAD
SPRING,VP,1E4
*END STEP
**
** STEP 2 - SEAL CAVITY (KEEP RIGID SURFACE FIXED)
**          NONLINEAR LOAD DEFLECTION CURVE
**
*STEP
*DYNAMIC,EXPLICIT, fixed
,.045
*RESTART,WRITE,NUMBER INTERVAL=2
*BOUNDARY, OP=NEW,AMPLITUDE=RAMP
1,1,3
4,1,6
6,1,1
RIGID,1
RIGID,3,6
RIGID,2,2,-.075
*END STEP