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

Moment curvature in weak axis

Moment curvature in weak axis

Moment curvature in weak axis

Can anyone please tell me when it comes to moment curvature analysis why do we focus on the strong axis of the walls only? Don’t we need to examine the displacement capability of the wall in weak direction more? I understand that the moment in weak axis can be ignore but the point of moment curvature analysis is to check the member’s displacement capacity and since the wall connects to the diaphragm that will drift in both direction, why don’t we check the moment curvature of wall in weak axis (out of plane) direction?

RE: Moment curvature in weak axis

It's a good question that I have wondered about myself. I built a 20'-0" long, 1'-0" thick wall with #5 at 12"oc, to aid in discussion.

Below is the moment rotation curves that I get with 0 axial load on the wall:

Strong Axis

Weak Axis

I want to build a model to confirm, but my guess is that typical loading/wall arrangements will never be able to develop 200kip*ft of moment in the out of plane direction (appears to be approximate onset of rebar yielding from the graph). I would guess that the wall just lacks enough stiffness to develop that much moment.


RE: Moment curvature in weak axis

Thank you. Do u mind tell me what software u used to generate these moment curvature?

RE: Moment curvature in weak axis

Software is called "Sketchulation", really cool software that has way more power than I know how to use currently. Kinda a mathcad/cross section analysis tool/general all purpose analysis program if you know how to use it.

Definitely the easiest arbitrary concrete cross section analysis tool I have used.


RE: Moment curvature in weak axis

Thank you.I will have a look.

RE: Moment curvature in weak axis

Not sure if I understand correctly. But, walls are very strong against bending in one direction and very weak on the other, if you have a building that has several walls spanning in both orthogonal direction (say X and Y axis) then loads coming from one direction, say x-axis, will be mainly resisted by walls having its strong axis at x-axis (due to force distribution by stiffness). Force coming from x-axis going to walls having a strong y-axis will be negligible.

RE: Moment curvature in weak axis

I just tried to search for Sketchulation but can only find a few videos and links to trademark registries. Is it still out there somewhere?

RE: Moment curvature in weak axis

Definitely still out there, but you are right it is not the easiest thing to google and find great info.
Youtube channel is here:


I will reach out to the creator of the software to see if he won't pop his head into this thread.


RE: Moment curvature in weak axis

From the creator:

Quote (Mike K.)

Anyone can try Sketchulation for free. Go to www.tippingapplications.com to register and request a trial license. It's free for students (need to have access to a valid edu email address) and for one month for everyone else.


RE: Moment curvature in weak axis

Thanks. Requiring people to register just so they can enter the website and read about the product seems a little silly....

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


Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now
The Great Project Profitability Debate
A/E firms have a great opportunity to lead the world into the future, but the industry’s greatest asset—real-time data—is sitting wasted in clunky, archaic ERP platforms. Learn how real-time, fully interactive dashboards in a modern ERP allow you to unlock data that will shape the future of the world. 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