Thank you both! That makes sense for Sec. III.
@TGS4, can you provide a Sec. VIII code citation where I can read it? My colleague prefers to see an actual statement from the code.
I'm using ASME, year 2023. In Sec. III and Sec. VIII vessel design, is there ever a situation where the service pressure of a defined load case may exceed the design pressure? For example, if design pressure is 100 psi, can I have a service load case that is defined at 150 psi? Please provide...
Thank you @TomLee777. But my question pertains to Pm in the ratchet calculation. And specifically, the question is, "is Pm a singular value (e.g., Pm from the design conditions in Part 5.2), or a range?"
Yes agreed. What prompted my original post is that I blindly assumed the equation would output valid answers all the way down to 0 ksi. But if I understand correctly from your feedback, it seems that the equations are only applicable down to 13.6 ksi. Thanks for helping me see that.
See the Mathcad image below for 2000 psi for 316 stainless at room temperature. Please also peek at my previously shared link HERE. The person graphed the natural log equation and it is going haywire as it goes below the fatigue limit.
*edit* My screenshot does not show n_k, which was earlier...
Is the Code Committee planning to fix the equations? Or was the added excerpt (quote below) supposed to act as the fix? It seemed insinuated HERE that they were actually fixing the equations themselves.
Folks, I found another thread HERE about Sec. VIII, Div. 2, Annex 3-F, Eqn. 8. The equation has something wrong with it. That old thread was dated from 2018. In the 2023 version of the Code, the problem still exists. Does anyone have a status update on when they plan to fix this...
Folks, I'm using Workbench v2023 to run a Static Structural FEA simulation. I have a simple model and want to apply an acceleration to the model. However, I want the acceleration applied to the boundary condition of the model, instead of the default, which is applying the acceleration to the...
Bump.
A friend said, "Pm is definitely not treated as a range in this situation. Rather, it is the Pm from Part 5.2, Protection Against Plastic Collapse." And they went on to say that it may be confusing because Pm used to be a range prior to the 2007 edition.
Does any of that ring a bell...
Folks, I am looking at 2023 ASME Sec. VIII, Div. 2, Part 5.5.6.3 for the Thermal Stress Ratchet check. This equation is provided...
Pm is referred to as "primary membrane stress." Is it supposed to be a primary membrane stress range? Everything in the fatigue and ratchet assessment up to...
Can you elaborate on this statement in Step 2 of the procedure?
My understanding is that if the top head's eigenvalue is 2, the bottom head's eigenvalue is 2.5, and the cylinder's eigenvalue is 3, I need to run a single elastic stress analysis having all three components present, but each...
Does that insinuate that each piece of the vessel should be run in the FEA separately (e.g., top head separate from the bottom head separate from the shell)? Or should the FEA analyze the entire vessel at the same time?
Folks, I am looking at 2023 ASME Sec. VIII, Div. 2, Part 5.4.2 for the Method A Buckling Analysis. I plan to use the ANSYS eigenvalue buckling solver to perform the work. Here are some excerpts from the code...
I see a common theme about "assessing individual components." If I have a...
I did a little research last night. From my understanding, it should be an SCL looking at both the primary membrane and primary bending (peak is excluded). So I could extract the six primary M+B components from my FEA model for Design Load Combination (1) and then derive the principal stresses...
Folks, I am looking at 2023 ASME Sec. VIII, Div. 2, Part 5.3.2 for the triaxial stress limit. It says...
Why do they put the word "linearized" in there? I understand the term's usage in the context of linearized through-wall stress for the checks in Part 5.2.2 (i.e., membrane, bending...
If I extracted Pm and Pb stress intensity from the software, and did the summation directly on stress intensity, rather than the components, would it be conservative? In other words, I would do this...
S_int_Pm + S_int_Pb
Since stress intensity is always positive, could I conclude that the...
Folks, I am using 2023 ASME Sec. III, Div. 5 for high temperature components. A common theme throughout BPVC is to sum at the component level. For example, Pm + Pb should be summed at the component level for the 6 stress components, before deriving stress intensity to check against the...
Does anyone here know how to directly contact forum admins? On a couple of my posts, I have used the "report" button to ask for the threads to be removed. But after a few days, I still see the threads on the forum. I'm not sure why they haven't been removed.
