×
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

FE stress analysis in VIII-2 Part 5

FE stress analysis in VIII-2 Part 5

FE stress analysis in VIII-2 Part 5

(OP)
Hi everybody
I'm to perform stress analysis by FE of some details of a pressure vessel in VIII div. 2 in this way:

1. Thermal analysis -> temp map.
2. Mech analysis for primary stress: temp map from step 1 + mech loads giving primary stress (engineer judgment...). To not introduce thermal stress THE THERMAL EXPANSION COEFF ARE TO BE SET EQUAL TO 0.
3. Mech analysis for secondary stress: temp map from step 1 + mech loads giving secondary stresses. THERMAL EXP COEFF. SET TO ACTUAL VALUES.

I'd use these procedure for both linear analysis (steps 1 and 2) and non-linear analysis (steps 1 to 3).
Please let me know if I'm right
Thanks

RE: FE stress analysis in VIII-2 Part 5

Nope. Simply put, the terms "secondary stress" and "nonlinear" should not be combined. Its either one (linear) or the other.

jt

RE: FE stress analysis in VIII-2 Part 5

(OP)
jte,
You'y right... I've been confused by the limits of the stresses...

But, despite that, my concern was about the way I split the calculation in steps 1 to 3.

Thanks again

RE: FE stress analysis in VIII-2 Part 5

I disagree.  According to Bednar, page 24, secondary loads can be non-linear, causing local deformation, but they are self-limiting, so that they do not lead to failure even though they cause a slight deformation.  Fig 2.1 on page 26 shows a stepwise deformation then return to the elastic range.   

RE: FE stress analysis in VIII-2 Part 5

MrBTU - in the context of performing a "nonlinear" analysis, the classification of stresses is irrelevant (that's what jte is saying).  If you classify, then you have to do an elastic/linear analysis.  If you do a nonlinear analysis, then no classification.

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