Hello to all,
There is a query regarding about Hog and Sag displacement.
Imagine a line running on ship Deck have Hog and sag displacement at support location.
My query is whether hog and sag Displacement at Partial anchor(ie Rest+Guide+Limit)will have zero displacement?
Will anchor have any displacement.

Awaiting your expert opinion
Regards,
Nitin Lonkar

For a vessel that has a single half-wave, along the ship, you will have to locations with 0 translation, but pure rotation, and 1 location at center with pure translation but no rotation. Depending on the size of the facility, however, you can have whole waves or multiple waves.

Everywhere else will have a combination of rotation and translation.

In the real world, you also have piping acting as a catenary and everything attempting to slide towards the lowest point, but CAESAR and we tend to ignore this. We also tend to simplify all rotations as translations. We rationalize this because the pipe is allowed to pivot around supports freely and naturally rotate.

In a static analysis, as far as piping stresses are concerned, it doesn't really matter which point on the pipe you say stays still, so long as the deflected shape meets reality. As far as restraints are concerned, however, the more accurate the model, the more accurate the restraint report.

In those systems with many supports you may wish to utilize the "import displacements" capability of CAESAR II.
Using your naval engineering data (hog/sag based on position with respect to the keel) can be built into an Excel spreadsheet. This data can be provided directly to CAESAR II.

Thanks Michael and Dave
But my Query regarding Displacement at Partial anchor(ie Rest+Guide+Limit) still pending.
Will displacement(Hog/Sag) at anchor will be zero
Could please help me on that
Thanks in advance!
Regards,
Nitin Lonkar

With a group of displaced positions I would suggest that there is only one anchor and all other supports move relative to that.
In CAESAR II you can move those other anchors by adding a CNode to those anchors and then define displacements/rotations (all 6 DOF) for these CNodes. If you don't want a support to see displacement, set all 6 to zero.
Perhaps this answers your question.

Thanks Dave this has really help me
Generally Hog/Sag Displacement at mid of ship is zero.
So it means we can put anchor with no displacement at support located mid of ship and then to put relative displacement for all other supports.
is it right?

Please Reply
Thanks in advance!
Nitin Lonkar

Yes. Bottom line: check your results to confirm.

Thanks Dave!