3d and 2d modelling of steel pipe rack

[allimuthug]

Hi,

Why pipe racks of modeled in 3d instead of 2d , Since lot of time is wasted in 3d analysis, Can any one specify good answer with justification .

 

[NOLAENG]

You have to design for lateral loads in at least both orthogonal directions.
So would you rather have 2 models for each direction or 1 that could encompass both?

 

[racookpe1978]

Many 3D analysis problems are not the simple "how much did it bend" ... look at the pretty 3D stress analysis graphics picture I made!"

In fact pipe racks are actually fairly straightforwards for a simple loads analysis. BUT!

A good 3D design check includes interferences, access, removal, installation, changes to other pipes and systems, and connections details. Other 3D packages do the BOM and sub-set building parts lists, and connection details, and connections accuracy (position, direction, specification, bolt matchup, material, etc.)

Biggest is the continual changes made during the design phases - by piping yes, but also by all of the other groups around piping racks.

 

[BUGGAR]

When I designed pipe racks, the pipers could never tell me where they were going to put the anchor points for large pipes. It became necessary to throw in longitudinal loads wherever they could happen and it was easier to just design the frame sets in 3d.

 

[Brad805]

A lot these days are using tools such as smartplant3d and other 3d modeling software for plant design. In these cases this does not add time, rather it can shorten it if the design and analysis programs are interoperable.

 

[MotorCity]

Here is my suggestion....

If the pipe rack consists of bents that are not connected to each other, a 2D frame analysis is adequate as long as you also include any out of plane loads (normal to pipe rack). Any loads transferred between the bents will have to travel through the piping, cable tray, etc. This will not occur as long as the bent is stiffer than the items on the bent (i.e. 99.99% of the time....I hope)

If the pipe rack consists of a series of bents that are connected to each other, a 3D analysis would be more appropriate because a load on one bent could easily have an effect on an adjacent bent.