Large rotation shell benchmark test

Highly motivated by Capacity of beam calculation - #13 by Uom0
I hereby try to test large rotation capabilities of calculix shell elements (to be expanded in solid ones) using a cantiliver beam as shown in the Figure,

The applied moment M should equal 2 times PI, times the Bending stiffness over the length, i.e. M=2PIEI/L when the beam is completely rolled.
I have created the following input file,

*NODE, NSET=NALL
1, 1, 0, 0
2, 2, 0, 0
3, 3, 0, 0
4, 4, 0, 0
5, 5, 0, 0
6, 6, 0, 0
7, 7, 0, 0
8, 8, 0, 0
9, 9, 0, 0
10, 10, 0, 0
11, 11, 0, 0
12, 12, 0, 0
13, 13, 0, 0
14, 14, 0, 0
15, 15, 0, 0
16, 16, 0, 0
17, 17, 0, 0
18, 18, 0, 0
19, 19, 0, 0
20, 20, 0, 0
21, 21, 0, 0
22, 22, 0, 0
23, 23, 0, 0
24, 24, 0, 0
25, 25, 0, 0
26, 26, 0, 0
27, 27, 0, 0
28, 28, 0, 0
29, 29, 0, 0
30, 30, 0, 0
31, 31, 0, 0
32, 32, 0, 0
33, 33, 0, 0
34, 34, 0, 0
35, 35, 0, 0
36, 36, 0, 0
37, 37, 0, 0
38, 38, 0, 0
39, 39, 0, 0
40, 40, 0, 0
41, 41, 0, 0
42, 42, 0, 0
43, 43, 0, 0
44, 44, 0, 0
45, 45, 0, 0
46, 46, 0, 0
47, 47, 0, 0
48, 48, 0, 0
49, 49, 0, 0
50, 50, 0, 0
51, 51, 0, 0
52, 52, 0, 0
53, 53, 0, 0
54, 54, 0, 0
55, 55, 0, 0
56, 56, 0, 0
57, 57, 0, 0
58, 58, 0, 0
59, 59, 0, 0
60, 60, 0, 0
61, 61, 0, 0
62, 62, 0, 0
63, 63, 0, 0
64, 64, 0, 0
65, 65, 0, 0
66, 66, 0, 0
67, 67, 0, 0
68, 68, 0, 0
69, 69, 0, 0
70, 70, 0, 0
71, 71, 0, 0
72, 72, 0, 0
73, 73, 0, 0
74, 74, 0, 0
75, 75, 0, 0
76, 76, 0, 0
77, 77, 0, 0
78, 78, 0, 0
79, 79, 0, 0
80, 80, 0, 0
81, 81, 0, 0
82, 82, 0, 0
83, 83, 0, 0
84, 84, 0, 0
85, 85, 0, 0
86, 86, 0, 0
87, 87, 0, 0
88, 88, 0, 0
89, 89, 0, 0
90, 90, 0, 0
91, 91, 0, 0
92, 92, 0, 0
93, 93, 0, 0
94, 94, 0, 0
95, 95, 0, 0
96, 96, 0, 0
97, 97, 0, 0
98, 98, 0, 0
99, 99, 0, 0
100, 99, 1, 0
101, 98, 1, 0
102, 97, 1, 0
103, 96, 1, 0
104, 95, 1, 0
105, 94, 1, 0
106, 93, 1, 0
107, 92, 1, 0
108, 91, 1, 0
109, 90, 1, 0
110, 89, 1, 0
111, 88, 1, 0
112, 87, 1, 0
113, 86, 1, 0
114, 85, 1, 0
115, 84, 1, 0
116, 83, 1, 0
117, 82, 1, 0
118, 81, 1, 0
119, 80, 1, 0
120, 79, 1, 0
121, 78, 1, 0
122, 77, 1, 0
123, 76, 1, 0
124, 75, 1, 0
125, 74, 1, 0
126, 73, 1, 0
127, 72, 1, 0
128, 71, 1, 0
129, 70, 1, 0
130, 69, 1, 0
131, 68, 1, 0
132, 67, 1, 0
133, 66, 1, 0
134, 65, 1, 0
135, 64, 1, 0
136, 63, 1, 0
137, 62, 1, 0
138, 61, 1, 0
139, 60, 1, 0
140, 59, 1, 0
141, 58, 1, 0
142, 57, 1, 0
143, 56, 1, 0
144, 55, 1, 0
145, 54, 1, 0
146, 53, 1, 0
147, 52, 1, 0
148, 51, 1, 0
149, 50, 1, 0
150, 49, 1, 0
151, 48, 1, 0
152, 47, 1, 0
153, 46, 1, 0
154, 45, 1, 0
155, 44, 1, 0
156, 43, 1, 0
157, 42, 1, 0
158, 41, 1, 0
159, 40, 1, 0
160, 39, 1, 0
161, 38, 1, 0
162, 37, 1, 0
163, 36, 1, 0
164, 35, 1, 0
165, 34, 1, 0
166, 33, 1, 0
167, 32, 1, 0
168, 31, 1, 0
169, 30, 1, 0
170, 29, 1, 0
171, 28, 1, 0
172, 27, 1, 0
173, 26, 1, 0
174, 25, 1, 0
175, 24, 1, 0
176, 23, 1, 0
177, 22, 1, 0
178, 21, 1, 0
179, 20, 1, 0
180, 19, 1, 0
181, 18, 1, 0
182, 17, 1, 0
183, 16, 1, 0
184, 15, 1, 0
185, 14, 1, 0
186, 13, 1, 0
187, 12, 1, 0
188, 11, 1, 0
189, 10, 1, 0
190, 9, 1, 0
191, 8, 1, 0
192, 7, 1, 0
193, 6, 1, 0
194, 5, 1, 0
195, 4, 1, 0
196, 3, 1, 0
197, 2, 1, 0
198, 1, 1, 0
199, 0, 1, 0
200, 0, 0, 0
201, 100, 0, 0
202, 100, 1, 0
******* E L E M E N T S *************
*ELEMENT, type=S4R, ELSET=EALL
1, 202, 100, 99, 201
2, 100, 101, 98, 99
3, 101, 102, 97, 98
4, 102, 103, 96, 97
5, 103, 104, 95, 96
6, 104, 105, 94, 95
7, 105, 106, 93, 94
8, 106, 107, 92, 93
9, 107, 108, 91, 92
10, 108, 109, 90, 91
11, 109, 110, 89, 90
12, 110, 111, 88, 89
13, 111, 112, 87, 88
14, 112, 113, 86, 87
15, 113, 114, 85, 86
16, 114, 115, 84, 85
17, 115, 116, 83, 84
18, 116, 117, 82, 83
19, 117, 118, 81, 82
20, 118, 119, 80, 81
21, 119, 120, 79, 80
22, 120, 121, 78, 79
23, 121, 122, 77, 78
24, 122, 123, 76, 77
25, 123, 124, 75, 76
26, 124, 125, 74, 75
27, 125, 126, 73, 74
28, 126, 127, 72, 73
29, 127, 128, 71, 72
30, 128, 129, 70, 71
31, 129, 130, 69, 70
32, 130, 131, 68, 69
33, 131, 132, 67, 68
34, 132, 133, 66, 67
35, 133, 134, 65, 66
36, 134, 135, 64, 65
37, 135, 136, 63, 64
38, 136, 137, 62, 63
39, 137, 138, 61, 62
40, 138, 139, 60, 61
41, 139, 140, 59, 60
42, 140, 141, 58, 59
43, 141, 142, 57, 58
44, 142, 143, 56, 57
45, 143, 144, 55, 56
46, 144, 145, 54, 55
47, 145, 146, 53, 54
48, 146, 147, 52, 53
49, 147, 148, 51, 52
50, 148, 149, 50, 51
51, 149, 150, 49, 50
52, 150, 151, 48, 49
53, 151, 152, 47, 48
54, 152, 153, 46, 47
55, 153, 154, 45, 46
56, 154, 155, 44, 45
57, 155, 156, 43, 44
58, 156, 157, 42, 43
59, 157, 158, 41, 42
60, 158, 159, 40, 41
61, 159, 160, 39, 40
62, 160, 161, 38, 39
63, 161, 162, 37, 38
64, 162, 163, 36, 37
65, 163, 164, 35, 36
66, 164, 165, 34, 35
67, 165, 166, 33, 34
68, 166, 167, 32, 33
69, 167, 168, 31, 32
70, 168, 169, 30, 31
71, 169, 170, 29, 30
72, 170, 171, 28, 29
73, 171, 172, 27, 28
74, 172, 173, 26, 27
75, 173, 174, 25, 26
76, 174, 175, 24, 25
77, 175, 176, 23, 24
78, 176, 177, 22, 23
79, 177, 178, 21, 22
80, 178, 179, 20, 21
81, 179, 180, 19, 20
82, 180, 181, 18, 19
83, 181, 182, 17, 18
84, 182, 183, 16, 17
85, 183, 184, 15, 16
86, 184, 185, 14, 15
87, 185, 186, 13, 14
88, 186, 187, 12, 13
89, 187, 188, 11, 12
90, 188, 189, 10, 11
91, 189, 190, 9, 10
92, 190, 191, 8, 9
93, 191, 192, 7, 8
94, 192, 193, 6, 7
95, 193, 194, 5, 6
96, 194, 195, 4, 5
97, 195, 196, 3, 4
98, 196, 197, 2, 3
99, 197, 198, 1, 2
100, 198, 199, 200, 1
*NSET,NSET=Nfixx
1,
2,
*MATERIAL,NAME=EL
*ELASTIC
210000,.3
*SHELL SECTION,ELSET=EALL,MATERIAL=EL,OFFSET=0.
1.0
*STEP, NLGEOM, inc=10000
*Static, direct
0.00005, 1,
*BOUNDARY
Nfixx,1,6
*CLOAD
201,5,300
202,5,300
*NODE PRINT,NSET=Nall
U,RF
*EL PRINT,ELSET=Eall
S
*NODE FILE,OUTPUT=3D
U
*EL FILE
*END STEP

but I am still getting convergence issues and problems to get a completely rolled configuration.
Can anyone take a look into this to suggest something else?.
Cheers,
/J.

You’re not supposed to exceed 90 degrees with moment load on shells in static:

[…] the user applied a rotation or a moment to a node.[…] in static calculations, starting with version 2.8 this type of loading is handled by using mean rotation MPC’s […] the rotation in a mean rotation MPC should not exceed 90 degrees.

Perhaps create a moment using opposing *DLOADs on two surfaces at the tip of the strip. I’ve done a rolled strip like that before, but not sure if it was CCX shells or not.

1 Like

Right. Thanks for your response Victor @vicmw .

Solved. Hopefully this will not be a problem any more.

Besides the issues others have already pointed out…

When I experimented with this type of thing, Mecway and ccx did not have automatic remeshing. Moreover, when the elements become so distorted that they are no longer valid. Without that, I don’t think this capability very useful. It’s something that ANSYS has had for a long time. The software needs element criteria checks and the ability to automatically remesh, whenever, the criteria is not met. Even now, just doing a static mesh there are no checks.

This particular benchmark has analytical solution. It is provided considering a limited number of elements and specific material properties that makes the convergence itself a challenge.
I will post the results to see how it compares with other commercial software.

Results. Unfortunately I haven’t found the way to impose the moment directly to the lip of the shell. Rotation driven and Moment is indirectly measured imposing both ends find at the base.

L 12 m
I 8.33E-05 m4
E 1.20E+06 Pa
Mo 8.33 Nm
Mmax 52.360 Nm Expected
Mmax measured 53.008 Measured S4 16 Elements
Mmax measured 38.252 Measured S4R 16 Elements

imagen

1 Like

model of solid element, deflections are true scale.

add higher rotation, it seems convergence is related to mesh.

Please try to adjust your contributions to the statement of the post.

SHELLS

however, no matter i modeling with shell or solid element, actually both are solid element in CalculiX except US3. But i’m still interested in what shell element models to be working for such cases.