Peter,

To answer your <em>"specific"</em> question:

The proper analysis of a piping system involves analyzing a number of different load cases (for <em>primary, secondary,</em> and <em>occasional</em> loads). The piping codes define how the stresses are to be computed for each of these load cases. In the CAESAR II output report, the column labeled <em>code stress</em> is the stress obtained using the particular code's equation for the particular load case in question.

You can get a list of all of the code equations used in CAESAR II by looking at the <em>Quick Reference Guide</em>, starting on page Q-9. If you don't have the hard copy of this small manual, you can find it on-line, from the <em>"help\documentation"</em> menu.

If this is your first endeavor into the world of <em>Pipe Stress Analysis</em>, make sure you discuss your model and the results with someone who has performed this sort of work before. There are assumptions (as John noted above) and limitations you need to be aware of.

The biggest limitation is that piping programs utilize the <em>3D Beam Element</em>. This means the computer sees your model as a series of infinitely thin sticks. In addition, the behavior of the piping system is assumed to be dominated by bending, limited to small deflections and rotations. You can't ask (or expect) the program to give you something that can't be described within these limitations. Hence your results for the beam between two anchors. There was no movement of the nodes, therefore there were no forces or moments, and consequently no stress. (Buckling and other 2nd order effects are beyond the scope of the 3D Beam element, and therefore beyond the scope of typical Pipe Stress Analysis).

I hope this helps.