Servus,

Ordinarily these wind anchor motions (WAM) are not considered. This in practice usually works out because although there may be many WAM cycles that are small and many more that are large their cumulative damage affect on the pipe is quite small. This is due to the fact that the piping geometry usually has adequate flexibility to keep the stresses of these imposed WAM displacements quite small.

However if you have a geometry and a pipe support/restraint system that is not adequately flexible for the WAM you can run into trouble!

So what stress level is too much????? Use the cumulative fatiuge calculation out of the B31.3 code 302.3.5 (1d) to see where your calculated stress puts you.

In 30 yrs + of this work I've only seen this become problematic a few times.

Auf Wiedersehn und...