*HEADING
 LINESPRING ELEMENTS: MODEL CHANGE VERIFICATION
*RESTART,WRITE
*PREPRINT,MODEL=YES,HISTORY=NO
**
** TEST 1: LINESPRINGS
**
*SYSTEM
0.,0.,0.,0.8660254,0.,-0.5
0.,1.,0.
*NODE,NSET=NALL
1,,
2,,1.
3,,1.,.5
4,,,.5
5,,.5
6,,1.,.25
7,,.5,.5
8,,,.25
51,,2.
52,,3.
53,,3.,.5
54,,2.,.5
55,,2.5
56,,3.,.25
57,,2.5,.5
58,,2.,.25
*SYSTEM
*NODE,NSET=NALL
11,,
12,,1.
13,,1.,-.5
14,,,-.5
15,,.5
16,,1.,-.25
17,,.5,-.5
18,,,-.25
21,,
22,,1.
23,,1.,.5
24,,,.5
25,,.5
26,,1.,.25
27,,.5,.5
28,,,.25
31,,
32,,1.
33,,1.,-.5
34,,,-.5
35,,.5
36,,1.,-.25
37,,.5,-.5
38,,,-.25
41,,2.
42,,3.
43,,3.,.5
44,,2.,.5
45,,2.5
46,,3.,.25
47,,2.5,.5
48,,2.,.25
*ELEMENT,TYPE=LS6,ELSET=ALL
1,2,5,1,12,15,11
2,22,25,21,32,35,31
*ELEMENT,TYPE=LS3S,ELSET=ALL
3,52,55,51
4,42,45,41
*ELEMENT,TYPE=S8R,ELSET=ALL
11,1,2,3,4,5,6,7,8
21,11,14,13,12,18,17,16,15
31,21,22,23,24,25,26,27,28
41,31,34,33,32,38,37,36,35
51,51,52,53,54,55,56,57,58
61,41,42,43,44,45,46,47,48
*ELSET,ELSET=LS
1,2
*ELSET,ELSET=LS
3,4
*ELSET,ELSET=TEST
1,11,21,3,51
*MATERIAL,NAME=M1
*ELASTIC
1.,.0
*DENSITY
1.0,
*SURFACE FLAW,SIDE=POSITIVE
1,.05
5,.05
2,.05
21,.05
25,.05
22,.05
51,.05
55,.05
52,.05
41,.05
45,.05
42,.05
*SHELL SECTION,MAT=M1,ELSET=ALL
.1,
*EQUATION
2,
1,1,1.,5,1,-1.
2,
2,1,1.,5,1,-1.
2,
8,1,1.,6,1,-1.
2,
4,1,1.,7,1,-1.
2,
3,1,1.,7,1,-1.
2,
11,1,1.,15,1,-1.
2,
12,1,1.,15,1,-1.
2,
18,1,1.,16,1,-1.
2,
14,1,1.,17,1,-1.
2,
13,1,1.,17,1,-1.
2,
1,2,1.,5,2,-1.
2,
2,2,1.,5,2,-1.
2,
8,2,1.,6,2,-1.
2,
4,2,1.,7,2,-1.
2,
3,2,1.,7,2,-1.
2,
11,2,1.,15,2,-1.
2,
12,2,1.,15,2,-1.
2,
18,2,1.,16,2,-1.
2,
14,2,1.,17,2,-1.
2,
13,2,1.,17,2,-1.
2,
4,3,1.,7,3,-1.
2,
3,3,1.,7,3,-1.
2,
8,3,1.,6,3,-1.
2,
1,3,1.,5,3,-1.
2,
2,3,1.,5,3,-1.
2,
11,3,1.,15,3,-1.
2,
12,3,1.,15,3,-1.
2,
18,3,1.,16,3,-1.
2,
14,3,1.,17,3,-1.
2,
13,3,1.,17,3,-1.
2,
1,5,1.,5,5,-1.
2,
2,5,1.,5,5,-1.
2,
11,5,1.,15,5,-1.
2,
12,5,1.,15,5,-1.
2,
21,1,1.,25,1,-1.
2,
22,1,1.,25,1,-1.
2,
28,1,1.,26,1,-1.
2,
24,1,1.,27,1,-1.
2,
23,1,1.,27,1,-1.
2,
31,1,1.,35,1,-1.
2,
32,1,1.,35,1,-1.
2,
38,1,1.,36,1,-1.
2,
34,1,1.,37,1,-1.
2,
33,1,1.,37,1,-1.
2,
21,2,1.,25,2,-1.
2,
22,2,1.,25,2,-1.
2,
28,2,1.,26,2,-1.
2,
24,2,1.,27,2,-1.
2,
23,2,1.,27,2,-1.
2,
31,2,1.,35,2,-1.
2,
32,2,1.,35,2,-1.
2,
38,2,1.,36,2,-1.
2,
34,2,1.,37,2,-1.
2,
33,2,1.,37,2,-1.
2,
24,3,1.,27,3,-1.
2,
23,3,1.,27,3,-1.
2,
28,3,1.,26,3,-1.
2,
21,3,1.,25,3,-1.
2,
22,3,1.,25,3,-1.
2,
31,3,1.,35,3,-1.
2,
32,3,1.,35,3,-1.
2,
38,3,1.,36,3,-1.
2,
34,3,1.,37,3,-1.
2,
33,3,1.,37,3,-1.
2,
21,5,1.,25,5,-1.
2,
22,5,1.,25,5,-1.
2,
31,5,1.,35,5,-1.
2,
32,5,1.,35,5,-1.
2,
41,1,1.,45,1,-1.
2,
42,1,1.,45,1,-1.
2,
48,1,1.,46,1,-1.
2,
44,1,1.,47,1,-1.
2,
43,1,1.,47,1,-1.
2,
51,1,1.,55,1,-1.
2,
52,1,1.,55,1,-1.
2,
58,1,1.,56,1,-1.
2,
54,1,1.,57,1,-1.
2,
53,1,1.,57,1,-1.
2,
41,2,1.,45,2,-1.
2,
42,2,1.,45,2,-1.
2,
48,2,1.,46,2,-1.
2,
44,2,1.,47,2,-1.
2,
43,2,1.,47,2,-1.
2,
51,2,1.,55,2,-1.
2,
52,2,1.,55,2,-1.
2,
58,2,1.,56,2,-1.
2,
54,2,1.,57,2,-1.
2,
53,2,1.,57,2,-1.
2,
44,3,1.,47,3,-1.
2,
43,3,1.,47,3,-1.
2,
48,3,1.,46,3,-1.
2,
41,3,1.,45,3,-1.
2,
42,3,1.,45,3,-1.
2,
51,3,1.,55,3,-1.
2,
52,3,1.,55,3,-1.
2,
58,3,1.,56,3,-1.
2,
54,3,1.,57,3,-1.
2,
53,3,1.,57,3,-1.
2,
41,5,1.,45,5,-1.
2,
42,5,1.,45,5,-1.
2,
51,5,1.,55,5,-1.
2,
52,5,1.,55,5,-1.
*AMPLITUDE,NAME=RAMP
0.,0., .5,1.0
**
**
*STEP
 STEP #1: DISPLACE TEST SPECIMEN SO FINAL SHAPE IS
          IDENTICAL TO INITIAL SHAPE OF REFERENCE ELEMENT 
*STATIC
0.25,1.
*PRINT,MODEL CHANGE=YES
*BOUNDARY,AMP=RAMP
NALL,6
17,1,5
15,1,5
37,1,5
35,1,5
45,1,2
55,1,2
5,5,5,-.523598775598
55,5,5,-.523598775598
*NODE PRINT,FREQ=999
RF, 
*EL PRINT,FREQ=999
S,
E,
*NODE FILE,FREQ=999
RF, 
*EL FILE,FREQ=999
E,
S,
*EL PRINT,ELSET=LS,FREQ=999
JK,
*EL FILE,ELSET=LS,FREQ=999
JK,
*OUTPUT,FIELD,FREQ=1
*ELEMENT OUTPUT,ELSET=LS
JK,
*OUTPUT,FIELD,FREQ=1
*NODE OUTPUT
RF,
U, 
*ELEMENT OUTPUT
E,
S,
*OUTPUT,HISTORY,FREQ=999
*NODE OUTPUT, NSET=NALL
RF, 
*END STEP
**
**
*STEP
 STEP #2: REMOVE TEST ELEMENTS
*STATIC
1.,1.
*MODEL CHANGE,REMOVE,TYPE=ELEMENT
TEST,
*END STEP
**
**
*STEP
 STEP #3: ADD TEST ELEMENTS BACK IN STRAIN-FREE
*STATIC
1.,1.
*MODEL CHANGE,ADD=STRAINFREE,TYPE=ELEMENT
TEST,
*BOUNDARY,OP=NEW
NALL,6
17,1,5
37,1,5
45,1,2
55,1,2
*END STEP
**
**
*STEP
 STEP #4: APPLY LOAD TO BOTH ELEMENTS 
*STATIC
0.25,1.
*CLOAD
5,5,-6
15,5,6
25,5,-6.
35,5,6.
45,5,-6.
55,5,-6.
*END STEP
**
**
*STEP
 STEP #5: REMOVE TEST ELEMENT
*STATIC
.25,1.0
*BOUNDARY,OP=NEW,FIXED
NALL,1,6
*MODEL CHANGE,REMOVE,TYPE=ELEMENT
TEST,
*END STEP
**
**
*STEP
 STEP #6: ADD TEST ELEMENTS BACK IN WITH-STRAIN
*STATIC
.25,1.0
*MODEL CHANGE,ADD=WITHSTRAIN,TYPE=ELEMENT
TEST,
*END STEP
**
**
*STEP
 STEP #12: DYNAMICS
*DYNAMIC
.5,5.
*BOUNDARY,OP=NEW
NALL,6
17,1,5
37,1,5
45,1,2
55,1,2
*EL PRINT,ELSET=LS,FREQ=999
JK,
*EL FILE,ELSET=LS,FREQ=999
JK,
*OUTPUT,FIELD,FREQ=1
*ELEMENT OUTPUT,ELSET=LS
JK,
*OUTPUT,FIELD,FREQ=1
*NODE OUTPUT
RF,
*EL PRINT,FREQ=999
S,
E,
*NODE PRINT,FREQ=999
RF, 
*CLOAD
5,5,-6.
15,5,6.
25,5,-6.
35,5,6.
45,5,-6.
55,5,-6.
*END STEP