I have a great problem I cannot solve and understand.

Imagine a piping with a lateral restraint with 10 mm gap.

When obtaining the displacement list in the cases SUSTAINED + WIND; the obtained value exceed surprisingly such 10 mm; being its value 10,22 mm.

why such thing habppens?.

Thanks a lot, again.

Simple.

If a pipe moves 5 mm in +X and 6 mm in -X then the total distance it has travelled is 11mm even though the gap is 10mm.

Remember you are measuring a difference.

Regards

Why do you say I am measuring a difference if the obtained report is of displacements and what is indicated is the distance from 0 till the final point?
Thanks.

Can you show what your load cases are, and how you generated the "sustained + wind" case?

Additionally, is your pipe (and therefore your restraint) aligned with the global coordinate system, or are things skewed at this location?

By difference I was referring to the computation of displacement in pure wind case where the displacement in OPE +WIND ( L1) can be 5 MM in +X and 6 mm in -6 mm in OPE (L2)case.

When you make L1-L2 it comes out to be 11 mm in DX.

I hope I have made myself clear to you.

Dear Richard,

Here they are the combiantion loads:

Nº Combination Name Comb.Method

1 W HGR
2 W+D1+T1+P1 HGR
3 WW+HP+H HYD
4 W+D1+T1+P1+H OPE1
5 W+D2+T2+P2+H OPE2
6 W+P1+H SUS1
7 W+P2+H SUS2
8 W+D1+T1+P1+H+WINX OPE1+WINDX
9 W+D1+T1+P1+H+WINZ OPE1+WINDZ
10 W+D1+T1+P1+H-WINX OPE1-WINDX
11 W+D1+T1+P1+H-WINZ OPE1-WINDZ
12 W+D1+T1+P1+H+U1 OPE1+SEISMX
13 W+D1+T1+P1+H+U2 OPE1+SEISMZ
14 W+D1+T1+P1+H-U1 OPE1-SEISMX
15 W+D1+T1+P1+H-U2 OPE1-SEISMZ
16 W+D2+T2+P2+H+WINX OPE2+WINDX
17 W+D2+T2+P2+H+WINZ OPE2+WINDZ
18 W+D2+T2+P2+H-WINX OPE2-WINDX
19 W+D2+T2+P2+H-WINZ OPE2-WINDZ
20 W+D2+T2+P2+H+U1 OPE2+SEISMX
21 W+D2+T2+P2+H+U2 OPE2+SEISMZ
22 W+D2+T2+P2+H-U1 OPE2-SEISMX
23 W+D2+T2+P2+H-U2 OPE2-SEISMZ
24 8-4 OPE1+WINDX-OPE1 Scalar
25 9-4 OPE1+WINDX-OPE1 Scalar
26 10-4 OPE1-WINDX-OPE1 Scalar
27 11-4 OPE1-WINDX-OPE1 Scalar
28 12-4 OPE1+SEISMX-OPE1 Scalar
29 13-4 OPE1+SEISMX-OPE1 Scalar
30 14-4 OPE1-SEISMX-OPE1 Scalar
31 15-4 OPE1-SEISMX-OPE1 Scalar
32 16-5 OPE2+WINDX-OPE2 Scalar
33 17-5 OPE2+WINDX-OPE2 Scalar
34 18-5 OPE2-WINDX-OPE2 Scalar
35 19-5 OPE2-WINDX-OPE2 Scalar
36 20-5 OPE2+SEISMX-OPE2 Scalar
37 21-5 OPE2+SEISMX-OPE2 Scalar
38 22-5 OPE2-SEISMX-OPE2 Scalar
39 23-5 OPE2-SEISMX-OPE2 Scalar
40 6+24 OPE1+WINDX-OPE1+SUS1 Scalar
41 6+25 OPE1+WINDX-OPE1+SUS1 Scalar
42 6+26 OPE1+WINDX-OPE1+SUS1 Scalar
43 6+27 OPE1+WINDX-OPE1+SUS1 Scalar
44 6+28 OPE1+SEISMX-OPE1+SUS1 Scalar
45 6+29 OPE1+SEISMX-OPE1+SUS1 Scalar
46 6+30 OPE1+SEISMX-OPE1+SUS1 Scalar
47 6+31 OPE1+SEISMX-OPE1+SUS1 Scalar
48 7+32 OPE2+WINDX-OPE2+SUS2 Scalar
49 7+33 OPE2+WINDX-OPE2+SUS2 Scalar
50 7+34 OPE2+WINDX-OPE2+SUS2 Scalar
51 7+35 OPE2+WINDX-OPE2+SUS2 Scalar
52 7+36 OPE2+SEISMX-OPE2+SUS2 Scalar
53 7+37 OPE2+SEISMX-OPE2+SUS2 Scalar
54 7+38 OPE2+SEISMX-OPE2+SUS2 Scalar
55 7+39 OPE2+SEISMX-OPE2+SUS2 Scalar
56 4-6 EXP1 Algebraic
57 5-7 EXP2 Algebraic


I Hope you can shed some light on this issue.

Lets narrow this down and discuss only cases 4, 6, 8, 24, and 40.

Case 4 is operating,
Case 8 is operating + wind

Case 24 is "case 8 - case 4", which yields the effects of wind. This is a difference, so Anindya's comment above is a possibility. I would suggest that you use an "algebraic" combination here instead of "scalar". Check the "help text" on this field for details. I also suggest that even though this is a "construction load case", you set the stress type to "OCC", so the correct stress equation is used. You're not really interested in viewing any of the results of this load case, since its purpose is simply to obtain the stresses due to wind in the operating position of the piping.

Case 40 is the stress summation of case 24 and case 6. The "scalar" summation is correct here, but also make sure you set the stress type to "OCC".

Also, at the location you are concerned about, is the piping skewed??