Dear all,

My question is regarding table 4.1.2. ASME VIII DivII 2007 (add. 2009). These load case combinations must be considered.

The standard 19 PVelite load cases do not seem to match the load cases in table 4.1.2. of the code.
One of the load cases from 4.1.2 is for example 0.9P+Ps+D+0.7E. When I now try to change a load case for this example IP->0.9IP the calculated stress intensity increases. This doesn't give me much confidence in the calculations for these load cases.

How should I approach table 4.1.2 using PVelite? Can it be done with the load cases in PVelite? I'm using version 2010.

Thanks in advance.

Joep van der List

Hello Joep

Using the 'Load Cases' tab, it is possible to enter these ratios (such as 0,9P) in the individual load cases.

Thank you Ray.

I did set the scalars in the way you mention in your post. However it is the result that confuses me. To check what is happening I set just two load cases. Case 1 with IP only and case 2 with 0.9IP only. Then the results give higher stress intensity's for case 2 and it says case 2 is the governing load case. I think this should not be possible? Or am I thinking wrong?

Joep

Please send the PV Elite file through to support -at- coade.com. We will review it and let you know.

Hello Joep

It is a little complicated. For example, when you reduce the internal pressure, the compressive stress may increase thus giving a higher ratio. The stresses come from three sources:

1 The moment from wind or seismic loading (or user entered forces)
2 The weight above the section under consideration
3 The pressure - positive or negative.

Each of these considerations can affect any of the other considerations. So the critical load case can change.

Ahh, the issue was resolved. It seems I just misunderstood the method of calcuation. Your help was appreciated.

Joep