*HEADING
AIRSPRING -- 180 DEG MODEL
******** NODAL DEFINITIONS
*PREPRINT,MODEL=YES
*NODE, NSET = FPLANE
*NGEN, LINE = C, NSET = FPLANE
*NCOPY, OLD SET = FPLANE, CHANGE NUMBER = 100, SHIFT,
MULTIPLE = 22,NEWSET=NALL
*NODE, NSET = RIGID
*NODE, NSET = CAVITY
******** RUBBER SPRING
*ELEMENT, TYPE = S4R
*ELGEN, ELSET = SPRING1
*ELGEN, ELSET = SPRING2
*ELSET,ELSET=SPRING
SPRING1,SPRING2
*SHELL SECTION, MATERIAL = RUBBER, ELSET = SPRING
6.0E-3,
*HOURGLASS STIFFNESS
*REBAR LAYER
PLSREBAR,1.E-6, 3.5E-3, 0,STEEL,18,1
MNSREBAR,1.E-6, 3.5E-3, 0,STEEL,-18,1
******** RIGID BODY (UPPER DISK)
*RIGID BODY,REFNODE=RIGID,ELSET=RIGELEM
*NODE,NSET=RIGNODE
*NGEN,NSET=RIGNODE,LINE=C
*NCOPY,OLDSET=RIGNODE,CHANGE NUMBER=100,SHIFT,
MULTIPLE=22,NEWSET=NALL
*ELEMENT,TYPE=R3D4,ELSET=RIGELEM
*ELGEN,ELSET=RIGELEM
*ELEMENT, TYPE=R3D3, ELSET=RIGELEM
** CONSTRAINT TO CONNECT TOP PORTION OF
** SPRING WITH RIGID DISK
*MPC
TIE, 40, 11001
TIE, 140, 11101
TIE, 240, 11201
TIE, 340, 11301
TIE, 440, 11401
TIE, 540, 11501
TIE, 640, 11601
TIE, 740, 11701
TIE, 840, 11801
TIE, 940, 11901
TIE, 1040, 12001
TIE, 1140, 12101
TIE, 1240, 12201
TIE, 1340, 12301
TIE, 1440, 12401
TIE, 1540, 12501
TIE, 1640, 12601
TIE, 1740, 12701
TIE, 1840, 12801
TIE, 1940, 12901
TIE, 2040, 13001
TIE, 2140, 13101
TIE, 2240, 13201
******* MATERIAL DEFINITIONS
*MATERIAL, NAME = RUBBER
*HYPERELASTIC, POLYNOMIAL, N = 1
3.2E6, 0.8E6
*MATERIAL, NAME = STEEL
*ELASTIC
2.1E11, 0.3
**
******** CONTACT DEFINITION
*ELSET, ELSET=SPRING2A, GENERATE
*SURFACE, NAME = ASURF
SPRING2A,SNEG
*SURFACE,TYPE=ELEMENT, NAME = RSURF
RIGELEM,SPOS
*CONTACT PAIR, INTERACTION = SMOOTH
ASURF, RSURF
*SURFACE INTERACTION, NAME = SMOOTH
**
******** FLUID CAVITY
*ELEMENT, TYPE = SFM3D3, ELSET = FLUID
*ELGEN, ELSET = FLUID
*SURFACE SECTION, ELSET=FLUID
*SURFACE, TYPE=ELEMENT, NAME=CAVSURF
 SPRING, SPOS
 FLUID, SPOS
*PHYSICAL CONSTANTS, ABSOLUTE ZERO=-273.16, UNIVERSAL GAS CONSTANT=8.314
*FLUID CAVITY, NAME=SPRING, BEHAVIOR=GAS, REF NODE=50000, SURFACE=CAVSURF, AMBIENT PRESSURE=101.36E+3
*FLUID BEHAVIOR, NAME=GAS
*MOLECULAR WEIGHT
******** NODE SETS
*NSET, NSET = N1M1, GENERATE
**101, 2201, 100
*NSET, NSET = N4, GENERATE
*NSET, NSET = N6, GENERATE
*NSET, NSET = N40, GENERATE
*NSET, NSET = N41, GENERATE
**41, 2241, 100
*NSET,NSET=RIG
N40
*NSET, NSET = YPLN1, GENERATE
*NSET, NSET = YPLN2, GENERATE
*MPC
TIE, N1M1, 1
TIE,  N41, 10000
*BOUNDARY
1,1,3
N4,1,6
N6,2,3
YPLN1, 2
YPLN1, 4
YPLN1, 6
YPLN2, 2
YPLN2, 4
YPLN2, 6
RIGID,1,6
*****************HISTORY DEFINITION *****************
**
** STEP 1 - INFLATION STEP (5 ATMOSPHERES)
**
*STEP, NLGEOM
*STATIC
0.02,1.0
*MONITOR, NODE=26, DOF=3
*BOUNDARY
CAVITY,8,8, 5.066E5
*NODE PRINT,NSET=CAVITY
PCAV,CVOL
*NODE PRINT, NSET=RIGID
U,
RF,
*OUTPUT,FIELD
*NODE OUTPUT
U,RF
CF,
*CONTACT OUTPUT,VARIABLE=PRESELECT,SLAVE=ASURF
*OUTPUT,HISTORY
*NODE OUTPUT,NSET=CAVITY
PCAV,CVOL
*NODE OUTPUT, NSET=RIGID
U, RF
CF
*print, solve=yes
*END STEP
**
** STEP 2 - SEAL CAVITY, RELEASE GRIP ON
** RIGID SURFACE, AND LOAD RIGID SURFACE
**
*STEP, NLGEOM, INC=100
*STATIC
1.0,1.0
*MONITOR, NODE=10000, DOF=1
*BOUNDARY, OP=NEW
1,1,6
N4,1,6
N6,2,3
YPLN1, 2
YPLN1, 4
YPLN1, 6
YPLN2, 2
YPLN2, 4
YPLN2, 6
RIGID,2,6
*CLOAD
RIGID,1,-75.E3
*OUTPUT,FIELD
*NODE OUTPUT
U,RF
*OUTPUT,HISTORY
*NODE OUTPUT,NSET=CAVITY
CVOL,PCAV
*print, solve=yes
*END STEP
**
** STEP 3 - PERTURBATION STEP
** 3 LOAD CASES
**
*STEP, PERTURBATION
*STATIC
*BOUNDARY, OP=NEW
1,1,6
N4,1,6
N6,2,3
YPLN1, 2
YPLN1, 4
YPLN1, 6
YPLN2, 2
YPLN2, 4
YPLN2, 6
** LOAD CASE 1
** UNIT AXIAL DISPLACEMENT
*LOAD CASE, NAME="UNIT AXIAL DISPLACEMENT"
*BOUNDARY, OP=NEW
RIGID,1,1, 1.E-3
RIGID,2,6
*END LOAD CASE
**
** LOAD CASE 2
** UNIT LATERAL DISPLACEMENT
*LOAD CASE, NAME="UNIT LATERAL DISPLACEMENT"
*BOUNDARY, OP=NEW
RIGID,3,3, 1.E-3
RIGID,1,2
RIGID,4,6
*END LOAD CASE
**
** LOAD CASE 3
** UNIT ROTATION
*LOAD CASE, NAME="UNIT ROTATION"
*BOUNDARY, OP=NEW
RIGID,5,5, 1.E-3
RIGID,1,4
RIGID,6,6
*END LOAD CASE
*OUTPUT,FIELD
*NODE OUTPUT
U,RF
*OUTPUT,HISTORY
*NODE OUTPUT,NSET=CAVITY
CVOL
*print, solve=yes
*END STEP
**
** STEP 4 - NONLINEAR LATERAL
** LOAD DEFLECTION CURVE
**
*STEP, NLGEOM, INC=100
*STATIC
0.1, 1.0
*CONTROLS,PARAMETERS=FIELD
,1.0
*MONITOR, NODE=10000, DOF=3
*BOUNDARY
RIGID,3,3, 2.E-2
*OUTPUT,FIELD
*NODE OUTPUT
U,RF
*OUTPUT,HISTORY
*NODE OUTPUT, NSET=CAVITY
 CVOL,PCAV
*print, solve=yes
*END STEP