Linearized Stress Output in Pressure Vessel Study

[CRMagruder]

I am using COSMOSWorks Pro to evaluate a pressure vessel with combined temperature and mechanical loads. The software has a feature to get a linearized stress output across a section of interest and produces these nice graphics with the stresses plotted across the section distance. There are six graphs for X,Y,Z Normal stress, and XZ, YZ, and XY Shear stress. Each graph has a plot of membrane stress, membrane plus bending, and another trace titled "Stress Results". See an example at

http://files.engineering.com/getfil...a-4bd1-ac8d-45207f616c73&file=Stress_Plot.JPG

I completely understand how to interpret the membrane and membrane + bending results, but I don't know what stress is represented by the "Stress Results" plot. Is this Peak Stress? Does anyone have experience with this feature? I would ask the software vendor, but we have not paid our maintenence fee for a year or so.

Thanks in advance,

Chuck

 

[cbrn]

Hi,
I suppose this is some kind of equivalent stress. I say "some kind" because I have no way of understanding which combination criteria it is based upon (Von Mises? Trescà?...). Anyway, let's suppose the routine is compatible with ASME: then, the linearization is based upon Stress Intensity (Trescà-based). The "sterss results" you see are most probably the "raw" results obtained from the FE-solution, "membrane" and "membrane+bending" being the "interpreted" data.
Can't be more precise, as I don't use CosmosWorks.

Regards

 

[corus]

I'd agree with cbrn. Comparing the stress results (curved) with the membrane + bending (linear graph), I'd say that the stress results are the original stress data and the membrane + bending is the linearised version of that graph.

corus