Contact US

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

Round HSS Pile - Plastic Hinge Structural Capacity

Round HSS Pile - Plastic Hinge Structural Capacity

Round HSS Pile - Plastic Hinge Structural Capacity

Dear all,

I have a question on my mind, I wonder if anyone can help me.

I am performing a structural evaluation in order to determine the structural capacity (using SAP2000) of an existing steel concrete cap structure supported by steel pipe piles (ASTM A36) when subjected to an abnormal horizontal displacement.

To evaluate it´s structural capacity I am performing a Nonlinear Time History Analysis using plastic hinges (SAP Automatic Fiber Hinge) but I am in doubt if I can follow the plastic hinge procedure due to width-to-thickness ratios (AISC Tables B4.1a and B4.1b).

Corroded Pile diameter and thickness are 0.505m and 0.008m respectively. Looking at AISC Table B4.1a, D/T (value=63.13) is less than 0.11 E/Fy (value=88). Being this I understand that I am dealing with a nonslender section and a plastic analysis could be performed.
But if I look at AISC Table B4.1b, I conclude that the same section is noncompact D/T > 0.07 E/Fy.

So my first question is, can I perform a Time History Analysis using plastic hinges on piles, knowing that they are subjected to compression and flexure and section is nonslender (compression) and noncompact (flexure)?

Second question: Is SAP2000 Automatic Fiber Hinge (P-M2-M3) the best feature to evaluate structural capacity for steel pipe piles?

Thanks for your help guys!

RE: Round HSS Pile - Plastic Hinge Structural Capacity

To develop the plastic section, a tube/pipe has to maintain it's x-section... some pipes and tubes buckle locally prior to developing their full plastic strength.


RE: Round HSS Pile - Plastic Hinge Structural Capacity

Hello dik, thanks a lot for your answer. I agree with your statement.

So regarding the pile case presented above, would you consider that a plastic analysis should not be performed?
In this case what should govern? The compression (being non slender) or flexure (being noncompact)?


RE: Round HSS Pile - Plastic Hinge Structural Capacity

I wouldn't normally use plastic design for that situation... I would think flexure would govern, but, you'd have to run the sums to verify it.


RE: Round HSS Pile - Plastic Hinge Structural Capacity

Thanks a lot dik for your comments!!!! :)

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


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