*HEADING
 Verification of multiple load cases in mdpeto3ctc_ml.inp, by replacing it with perturbation steps
  Multiple Load case test for hyperelasticity, element type - continuum-CAX4
DRUCKER PRAGER/POROUS ELASTICITY, CRITERION=EXP W/ TEST DATA, TC, CAX4
*NODE,NSET=SOIL
1,
3,1.
23,1.,1.
21,0.,1.
*NGEN,NSET=BOT
1,3
*NGEN,NSET=TOP
21,23
*NGEN,NSET=LHS
1,21,10
*NGEN,NSET=RHS
3,23,10
*ELEMENT,TYPE=CAX4,ELSET=SOIL
1,1,3,23,21
*SOLID SECTION,ELSET=SOIL,MATERIAL=SAMPLE
*MATERIAL,NAME=SAMPLE
*POROUS ELASTIC
1.49,.1
*DRUCKER PRAGER,SHEAR CRITERION=EXPONENT,TEST DATA
,,,10.
*TRIAXIAL TEST DATA,B=1.0
0,-100.0
0,88.897
*DRUCKER PRAGER HARDENING
100.,.0
500.,.5
*INITIAL CONDITIONS,TYPE=RATIO
SOIL,4.1,-10.,4.1,10.
*INITIAL CONDITIONS,TYPE=STRESS
SOIL,-70.,-70.,-70.
*BOUNDARY
LHS,1
BOT,2
*STEP,INC=1
*STATIC
.0001,.0001
*DLOAD
1,P2,70.
1,P3,70.
*EL PRINT
S,MISES,PRESS
E,VOIDR
PE, 
*NODE PRINT
U,RF
*OUTPUT,FIELD,FREQ=10
*ELEMENT OUTPUT
S,E,PE,VOIDR
*END STEP
*STEP,INC=20,NLGEOM
*STATIC,DIRECT
.05,1.
*BOUNDARY
21,2,,-.5
23,2,,-.5
*END STEP

*STEP,PERTURBATION
*STATIC
.0001,.0001
*LOAD CASE,NAME=DLOAD
*DLOAD
1,P2,70.
1,P3,70.
*END LOAD CASE
*LOAD CASE,NAME=PUSH
*BOUNDARY
21,2,,-.5
23,2,,-.5
*END LOAD CASE
*EL PRINT
VOIDR
MISES,PRESS
E,S
PE, 
*NODE PRINT
U,RF
*OUTPUT,FIELD,FREQ=10
*ELEMENT OUTPUT
S,E,PE,VOIDR
*END STEP