×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

ASME plastic coupled analysis

ASME plastic coupled analysis

ASME plastic coupled analysis

(OP)
Dear all,

I have problem with ASME coupled analysis. I have one structure for which I performed coupled thermal-mechanical analysis (acc. to ASME, section VIII, Div 2, article 4-1). There can be used linear analysis. Everything seems to be clear for me.

Unfortunately I have another one structure where plasticity is reached for mechanical load (local stress concentration). Moreover the limits (Fig. 4-130.1) are not satisfied  as it is mentioned in "4-136.5 Plastic analysis". There is some more explanations in this 4-136.5 section. I do not quite get it. Please explain shortly step by step this approach.

RE: ASME plastic coupled analysis

Pawel27 (Structural)

What year of ASME SECTION VIII, DIV. 2 IS YOUR REFERENCE?

L S THILL

RE: ASME plastic coupled analysis

(OP)
ASME 2004

RE: ASME plastic coupled analysis

ASME SECTION VIII DIV 2 PART 5 2007 OR 2010

RE: ASME plastic coupled analysis

LSThill,
        If you read the response I beleive it says "ASME 2004" if I am not mistaken!!!

RE: ASME plastic coupled analysis

(OP)
Yes, ASME 2004. There is Appendix 4 "Design basen on stress analysis". Interesting publications title are also desirable.

RE: ASME plastic coupled analysis

LSThill,
        You seem to have gone quiet now!!!! Looking for some "Cut and Paste" bibliography??

RE: ASME plastic coupled analysis

(OP)
Men... such posts are not valuable and lead to nothing. I counted on more practical and advanced posts.

RE: ASME plastic coupled analysis

Just trying to get an answer for you from this guy.... Women always whinging even when you try and help!!!

RE: ASME plastic coupled analysis

Maybe I can help.  The section that you are referring to is from an obsolete edition of ASME Section VIII, Division 2.  The current edition (at the very least, the 2007 or newer edition) completely re-wrote the entire old Appendix 4.

The 2004 edition does not do a very good job of explaining how the calculations are to be performed, particularly with respect to performing FEA.  However, that problem has mostly been resolved.

Therefore, rather than trying to explain to you the old rules, I would highly recommend that you review Article 5.2.4 in the newer editions.  If things are not cleared up, then please come back here with questions.

RE: ASME plastic coupled analysis

(OP)
Hmm... I did not read new 2007 ASME yet, because I am pushed on using Eurocode. I found similar method in EN 13445-3, Annex C. In fact used code is not so important (I guess) in this discussion. Some issues are discussed here thread727-211759: Peak stress in solid FE models. I would like to continue this discussion.
I have problem with stress categorization. At the connection pipe-hdr there is stress concentration. I hesitate between Local Membrane stress and Secondary stress. These are stress from mechanical loads. These "big stress" are locally mainly due to hdr twisting ("header" I mean this horizontal hdr at the picture). Actually I categorized all stress below 1.5f as Local membrane, and all stress above 1.5f as secondary stress
(i.e. stress which cause plastic deformations). Limits are on the basis of Table C-3, EN 13445-3.

Some comments:
material 16Mo3
f=157/1.5=104.6MPa (section 6 of EN 13445-3)
1.5f=157MPa

In fact it is not important what code we discuss. The most important is what to do with stress above yield limit in coupled thermal - mechanical analysis.

I would like to mention that on the picture are stresses from mechanical load. I would like to impose also thermal stress (at the next analysis stage). Thermal and mechanical Stress superpisition is not allowed due to plasticity.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources