Post-processing Secondary Membrane of Pressure Vessel

please define "secondary membrane" or link to a reference

SWX is WYSIWYG, so if you can't find it, you may need to pull data and do it yourself

This can be rather tricky to do and is an issue with trying to use FEA results (i.e. a continuous stress field) with standardized design codes. My (limited) understanding is that there is no direct and formally accepted method, but there some potential solutions.

Your FEA analysis calculated the total stress across the domain, but to use these results with the ASME code, you'll need to decompose this total stress value into the primary and secondary stress components, which you might be able to do by:

1. Use hand calculations to relate the primary stress to the applied loads. If you can't do this, then you'd essentially be left assuming that the total stress is all primary (a conservative assumption).
2. If you know an area where the total stress is dominated by the secondary stress, then you can use this to get an estimate. This can be very hard to do in practice however.