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!

*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

Impact testing of annular plates vs bottom plates

Impact testing of annular plates vs bottom plates

Impact testing of annular plates vs bottom plates

Hi all,

I am currently working on an AST project where the MDMT is -20 C- due to which we cant use our usual go to material, A-36, for shell and annular plates unless its impact tested (understandably so). Long story short, after discussing with our client, all shell plates above ~14mm are being designed for ASTM A 516 60 and those lower than that are being designed for A-36 Group 2 as per Figure 4.1a in API 650.

My question stems from a discussion I had with my colleagues regarding the stipulation in and why annular plates/sketch plates fall under this category but the rest of the bottom plates do not. They argue that the whole bottom is still in contact with the fluid and will experience similar loads(they are lap welded to the annular plates, after all) so why should it be different from the annular plates? My contention was that the shell-bottom joint acts as a rigid joint and hence experiences greater dynamic stresses and moments that the shell experiences due to the attached piping.

Can the good people here elucidate the matter and give their own inputs?

RE: Impact testing of annular plates vs bottom plates

When the liquid load is added in the shell, the shell expands more or less uniformly except at the bottom, where it is restrained by the bottom plate. So part of the hoop force that would normally be resisted by the shell is transferred into the bottom plate. I assume this is the motivation for requiring annular plates in larger/higher stressed tanks, and also the reason for requiring the notch toughness in this area.

RE: Impact testing of annular plates vs bottom plates

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! Already a Member? Login


eBook - Functional Prototyping Using Metal 3D Printing
Functional prototypes are a key step in product development – they give engineers a chance to test new ideas and designs while also revealing how the product will stand up to real-world use. And when it comes to functional prototypes, 3D printing is rewriting the rules of what’s possible. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close