Hello,
I have an harmonic study to perform: turbine alimentation with points to solicited on X, Y and Z (80 separate loads).
The calculation is running correctly.
1/ Efforts on solicited supports:
My first question is the following:
How could I obtain the resulting forces on the supports (some of the supports are among the solicited points)? For those supports I obtain such efforts:”*********************” -> huge resultants whereas this is not the case.
Idea:
We could consider a huge mass ex: 1000 tones and jointed via (Cnodes+”0”displacement) to all solicited supports blocking the same direction than the supports.
If we apply the amplitude displacement to this masse:
**We can solicit more than 100 points in the 3 direction… (quid fatal error #835 and CaesarII limitation and previous question on the forum)
**We could obtain resultant on solicited supports (I think that yes but what do you thing of this way to do it?)
Other Ideas witch "relatively" works (not accurate and depends on the considered segment length) is to consider the sum of upstream and downstream element forces (sum because the element force sense is opposite). What do you think of it… ?
2/Solicited supports and gap:
Concerning the solicited supports, some of them integer gaps…
For example:
10 mm gap in X direction, 0 mm gap in Y direction.
For harmonic study along X, 9.8mm are taken by my base case (operating case with temperature) and my harmonic solicitation amplitude is 0.17mm.
**Basically the resultant for this support in X direction is “-1 N ” that in to say 0 N -> no contact (logical because 9.8+1.7<10)
**In the Y direction, no gap, the support resultant is “*******************”->huge
One of the input data is friction coefficient, it mets us think that the harmonic calculation is none-linear calculation.
But is it really the case: if there is any piping vibration amplification, do the pipe is “able” to go in contact with the support:
[9.8mm+1.7mm+Xmm (induce by amplification)] >10mm, //
NB: 0.03mm is very small there is no change there is any contact
In this context, how Caesar II manage contact during harmonic calculation?? Is there a chance I obtain “reliable” output data for support (solicited or not) resultant in direction with gaps?
Thank you in advance.
Best regards
MH