*HEADING
 o FOUR PLANE STRAIN ELEMENTS (CPE4)
 o ONE ELASTIC MATERIAL
 o DSA CONTROLS
*PARAMETER
YC = 0.0
NU = 0.1 
*DESIGN PARAMETER
YC,  NU
*NODE
1, 0.0, 0.0, 0.0
2, 1.0, 0.0, 0.0
3, 2.0, 0.0, 0.0
4, 0.0, 1.0, 0.0
5, 1.0, 1.0, 0.0
6, 2.0, 1.0, 0.0
7, 0.0, 2.0, 0.0
8, 1.0, 2.0, 0.0
9, 2.0, 2.0, 0.0
*PARAMETER SHAPE VARIATION, PARAMETER=YC
8, 0.0, 1.0, 0.0
9, 0.0, 2.0, 0.0
*NSET, NSET=FIXED
1, 
*NSET, NSET=ROLL
2, 3
*ELEMENT, TYPE=CPE4, ELSET=EALL
1, 1, 2, 5, 4
2, 2, 3, 6, 5
3, 4, 5, 8, 7
4, 5, 6, 9, 8
*SOLID SECTION, MATERIAL=ABAQUS, ELSET=EALL
*MATERIAL, NAME=ABAQUS
*ELASTIC
2.0E05,<NU>
*BOUNDARY
FIXED, 1, 2, 0.0
ROLL,  2, 2, 0.0
*DSA CONTROLS, FORMULATION=TOTAL
YC,CD,1.0e-07
**
**FIRST STEP
**
*STEP,DSA
*STATIC,DIRECT
0.2,1.0
*DLOAD
3, P3, 100.0
4, P3, 100.0
*DESIGN RESPONSE, FREQUENCY=5
*NODE RESPONSE
U,RF
*ELEMENT RESPONSE
S,E
*OUTPUT, FIELD, FREQUENCY=5
*NODE OUTPUT
U,RF
*ELEMENT OUTPUT
S,E
*OUTPUT, HISTORY, FREQUENCY=0
*END STEP
**
** SECOND STEP
**
*STEP, PERTURBATION
*STATIC
*DLOAD
3, P3, 100.0
4, P3, 100.0
*OUTPUT, FIELD, FREQUENCY=5
*NODE OUTPUT
U,RF
*ELEMENT OUTPUT
S,E
*OUTPUT, HISTORY, FREQUENCY=0
*END STEP
**
** THIRD STEP
**
*STEP
*STATIC,DIRECT
0.2,1.0
*DLOAD
3, P3, 200.0
4, P3, 200.0
*OUTPUT, FIELD, FREQUENCY=5
*NODE OUTPUT
U,RF
*ELEMENT OUTPUT
S,E
*OUTPUT, HISTORY, FREQUENCY=0
*OUTPUT, FIELD, FREQUENCY=5
*NODE OUTPUT
U,RF
*ELEMENT OUTPUT
S,E
*DESIGN RESPONSE, FREQUENCY=5
*NODE RESPONSE
U,RF
*ELEMENT RESPONSE
S,E
*END STEP