Hi,

I am modeling a piping route which has a few ends capped. I read on this forum the increased rigidity of caps could be modeled as rigid elements. So that's what I did. I modeled rigid elements at the capped ends of same length as the caps and of same weight as a pipe element of the cap length.

When I run the analysis, I obtain displacements at capped ends but they seem restrained a bit on rotation making the supposedly unrestained ends bend. There is nothing else in the CAESAR II documentation about rigid elements other than the mention of how the weight is computed.

I included the CAESAR II file if you want to have a look. By the way, I know I have a lot of stress at anchors. I will need to add pipe shoes and possibly expansion joint(s).

Thanks in advance for the help.

There is nothing wrong with the displacements of the caps. They are not restrained. But everything is wrong with your routing, you have to provide more flexibility. Are you anchors realy fixed points with 0 displacement?

No. My anchors probably will move a few millimeters but I chose infinite rigidity to have a worse case scenario. As I said, expansion joint(s) are being added to the routing. Thanks for the input.

Getting back to caps, look at the animation of the pipe growth. There seems to be an abnormal bending moment at the caps location. That's what I noticed at first.

With this configuration is exactly how it should move.

Regards,

Thanks Danb

Welcome.

If you replace the anchor at 135 with a XZ restraint (only as an example) you may see that will move different.

In the first case it is the tee that rotate and the cap (which is a free end) will rotate as well.

Regards,