Initial velocity is not transferred to the expanded nodes in dynamic analyses

[FEA-eng]

In dynamic analyses involving expanded elements, initial velocity is not working properly. I attached an example below (with plane stress elements and explicit dynamics but the same happens in implicit dynamics). If you remove the *Surface, name=dummy definition, the initial velocity is not working - the part does not move at all. So a surface based on the node set used for the initial velocity condition has to be defined.

Forum discussion: https://calculix.discourse.group/t/cant-get-simple-explicit-dynamics-impact-analysis-to-work/1910/5

This issue was also reported for shell and beam elements and may require more complex workarounds or no complete workarounds may exist: https://calculix.discourse.group/t/initialconditions-type-velocity-for-shell-elements/710

*Node
1, -2.00000000E+002, 2.05000000E+002
2, 0.00000000E+000, 2.05000000E+002
3, -4.00000000E-016, 1.95000000E+002
4, -2.00000000E+002, 1.95000000E+002
5, -1.92000000E+002, 2.05000000E+002
6, -1.84000000E+002, 2.05000000E+002
7, -1.76000000E+002, 2.05000000E+002
8, -1.68000000E+002, 2.05000000E+002
9, -1.60000000E+002, 2.05000000E+002
10, -1.52000000E+002, 2.05000000E+002
11, -1.44000000E+002, 2.05000000E+002
12, -1.36000000E+002, 2.05000000E+002
13, -1.28000000E+002, 2.05000000E+002
14, -1.20000000E+002, 2.05000000E+002
15, -1.12000000E+002, 2.05000000E+002
16, -1.04000000E+002, 2.05000000E+002
17, -9.60000000E+001, 2.05000000E+002
18, -8.80000000E+001, 2.05000000E+002
19, -8.00000000E+001, 2.05000000E+002
20, -7.20000000E+001, 2.05000000E+002
21, -6.40000000E+001, 2.05000000E+002
22, -5.60000000E+001, 2.05000000E+002
23, -4.80000000E+001, 2.05000000E+002
24, -4.00000000E+001, 2.05000000E+002
25, -3.20000000E+001, 2.05000000E+002
26, -2.40000000E+001, 2.05000000E+002
27, -1.60000000E+001, 2.05000000E+002
28, -8.00000000E+000, 2.05000000E+002
29, -8.20000000E+000, 1.95000000E+002
30, -1.62000000E+001, 1.95000000E+002
31, -2.42000000E+001, 1.95000000E+002
32, -3.22000000E+001, 1.95000000E+002
33, -4.00000000E+001, 1.95000000E+002
34, -4.80000000E+001, 1.95000000E+002
35, -5.60000000E+001, 1.95000000E+002
36, -6.40000000E+001, 1.95000000E+002
37, -7.20000000E+001, 1.95000000E+002
38, -8.00000000E+001, 1.95000000E+002
39, -8.80000000E+001, 1.95000000E+002
40, -9.60000000E+001, 1.95000000E+002
41, -1.04000000E+002, 1.95000000E+002
42, -1.12000000E+002, 1.95000000E+002
43, -1.20000000E+002, 1.95000000E+002
44, -1.28000000E+002, 1.95000000E+002
45, -1.36000000E+002, 1.95000000E+002
46, -1.44000000E+002, 1.95000000E+002
47, -1.52000000E+002, 1.95000000E+002
48, -1.60000000E+002, 1.95000000E+002
49, -1.68000000E+002, 1.95000000E+002
50, -1.76000000E+002, 1.95000000E+002
51, -1.84000000E+002, 1.95000000E+002
52, -1.92000000E+002, 1.95000000E+002
*Element, Type=CPS4, Elset=Shell_part-2
1, 5, 1, 4, 52
2, 6, 5, 52, 51
3, 7, 6, 51, 50
4, 8, 7, 50, 49
5, 9, 8, 49, 48
6, 10, 9, 48, 47
7, 11, 10, 47, 46
8, 12, 11, 46, 45
9, 13, 12, 45, 44
10, 14, 13, 44, 43
11, 15, 14, 43, 42
12, 16, 15, 42, 41
13, 17, 16, 41, 40
14, 18, 17, 40, 39
15, 19, 18, 39, 38
16, 20, 19, 38, 37
17, 21, 20, 37, 36
18, 22, 21, 36, 35
19, 23, 22, 35, 34
20, 24, 23, 34, 33
21, 25, 24, 33, 32
22, 26, 25, 32, 31
23, 27, 26, 31, 30
24, 28, 27, 30, 29
25, 2, 28, 29, 3
*Nset, Nset=Shell_part-2_fromEl
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 
17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 
33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 
49, 50, 51, 52
*Elset, Elset=Internal_Selection-1_Solid_Section-1
Shell_part-2
*Surface, name=dummy, type=node
Shell_part-2_fromEl
*Material, Name=S235
*Density
7.8E-09
*Elastic
210000, 0.28
*Solid section, Elset=Internal_Selection-1_Solid_Section-1, Material=S235
10
** Name: Velocity-1
*Initial conditions, Type=Velocity
Shell_part-2_fromEl, 1, 1500
*Step, Nlgeom, Inc=10000000
*Dynamic, Explicit=3
1E-05, 0.0001, 1E-15, 1E-05
*Output, Frequency=100
*Node file
RF, U, V
*El file
S, E, ENER
*End step

[FEA-eng]

Not fixed in ccx 2.22.