×
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

Elastic Section Modulus or Plastic Section Modulus?

Elastic Section Modulus or Plastic Section Modulus?

Elastic Section Modulus or Plastic Section Modulus?

(OP)
Hello,

What is the difference between using Elastic Section Modulus (S) and Plastic Section Modulus (Z). I am desigining a base plate which happens to work if using Z, but it does not if using S. I am working usin Limit States Dedign (Canadian Code). Thanks for any input..

RE: Elastic Section Modulus or Plastic Section Modulus?

The elastic section modulus relates to when the extreme outer fiber of your section has reached yield. The plastic section modulus relates to when the full cross section has reached yield.

RE: Elastic Section Modulus or Plastic Section Modulus?

(OP)
Thanks SteelPE,

That means that when using plastic section modulus, I am using the full capacity of a section; so if using elastic instead of plastic, am I being just conservative? or what other implications may have using one or the other?... Thanks again

RE: Elastic Section Modulus or Plastic Section Modulus?

The Canadian Code recognizes LSD, Limit States Design (RLFD, Load and Resistance Factor Design in USA). The factored moment resistance, Mr = phi*Z*Fy for Class l and 2 sections. A base plate would be Class l.

The section modulus S would be used for determining stresses within the elastic range. It is also used in determining Mr for Class 3 sections (not applicable to a base plate).

Look at page 1-33, Article 13.5 in your CISC Handbook of Steel Construction.

BA

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