Pipe Clamp, how to apply supports 1

[imransaeed1804]

Hi,
Its my first post here. I hope it goes well. I am designing a pipe clamp. I have not modelled the pipe itself, as I need to apply moment and forces on the face resting on the pipe (bore of top block). However I am struggling to constrain the top block. Right now I have put a cylindrical support on the top bolt holes (restraining it vertically). But I don't think its the right representation. If I fix the bore of the clamp (with a fixed support), there is no deformation in the top direction, which is also not what I am expecting. Can anybody please advise what will be the best way to constrain the top clamp. I have attached pictures.

Best Regards

 

[rickfischer51]

Place a cylindrical coordinate system with the z axis on the pipe centerline, then place an x displacement = 0 with the coordinate system in the displacement detail set to the cylindrical coordinate system you made.

Rick Fischer
Principal Engineer
Argonne National Laboratory

 

[imransaeed1804]

rickfischer51,
Thanks for your reply, I really appreciate that. I understand what you are trying to say. However that will limit the inside bore of the top block both in +x and -x directions (I suppose, correct me if I am wrong). However I just want to restrict it towards the pipe (-x axis of the co-ordinate system that you have proposed). What do you think?

 

[scheah]

Including the pipe in your model may be necessary for what you're after.

Kind regards,
Jason

 

[rickfischer51]

Do you really think the clamp will pull away from the pipe anywhere along its nominal contact patch? You are currently applying a bearing load, which is a uniformly distributed radial force, which is an idealzation. If the top block pulled away from the pipe, there would be no load there, so either boundary condition would be in error. Fixing the hole in the radial direction is at least as good of an idealization as applying a bearing load.



Rick Fischer
Principal Engineer
Argonne National Laboratory

 

[imransaeed1804]

WellI end-up modelling pipe as well, Which gave me a very good result. In fact I also modelled the base structure as well.
Thanks sk_cheah

Do you really think the clamp will pull away from the pipe anywhere along its nominal contact patch? You are currently applying a bearing load, which is a uniformly distributed radial force, which is an idealzation. If the top block pulled away from the pipe, there would be no load there, so either boundary condition would be in error. Fixing the hole in the radial direction is at least as good of an idealization as applying a bearing load.

Well I do expect the front edge to move a little bit towards positive y due the moment about z-axis. So I ended up modelling the pipe as well. See attached pic.

 

[rickfischer51]

OK. But did the contact actually open anywhere on the pipe? If not, a fixed radial deflection might have been a reasonable assumption. Adding contact was not a big deal with a simple model like this, but a large model with lots of contact could prove difficult to solve, and fixing some of the contact would help. You might want to try your model without contact and various BCs on the bore, then compare the results to your results with contact.

Rick Fischer
Principal Engineer
Argonne National Laboratory

 

[imransaeed1804]

Rick,
That's a very good point. I will try to model it without contact. Thanks.