×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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

Lateral deflection estimation of portal frame

Lateral deflection estimation of portal frame

Lateral deflection estimation of portal frame

(OP)
Hello

I'm going to sit the IStructE exam this year and therefore compiling a variety of shorthand techniques. The portal method gives a good approximation for calculating moments and shears in a multistorey frame. Does anyone know of a simple approach to calculating associated lateral deflection due to horizontal loads?

Thanks

RE: Lateral deflection estimation of portal frame

One good method is to apply virtual work to your portal method sub-assemblages using the moment diagrams that you determined using the portal method. I know, it sounds onerous. However, because your moment diagrams are just triangles, it simplifies quit nicely.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

RE: Lateral deflection estimation of portal frame

There's also a good method by Muto in the appendices to Priestley and Paulay's classic text on the seismic design of concrete and masonry buildings. You'd need to be able to bring some charts with you however.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

RE: Lateral deflection estimation of portal frame

(OP)
Hello KootK

Oh great, that's good news. Searched a long time on Web for references. Do you know a good example solution for this?

RE: Lateral deflection estimation of portal frame

You can find virtual work examples most anywhere. The only place that I've seen the method developed specifically in conjunction with the portal frame method is in this book by Lynn Beedle Link

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

RE: Lateral deflection estimation of portal frame

I had this portal deflection question posed to me at my graduate oral exams. The answer was that you can simply take the moment diagrams up the length of one column and use the moment area method to get the deflection quickly at the top. Similar to KootK's first post above.

Check out Eng-Tips Forum's Policies here:
FAQ731-376: Eng-Tips.com Forum Policies

RE: Lateral deflection estimation of portal frame

(OP)
Okay, so having had a look at virtual work and moment area method I think I've found a simple short hand technique for calculating inter storey deflections. Attached pdf of the approach, could anyone verify if this is the correct interpretation. I cant find a specific example online to compare with but tallies with a portal frame modelhttps://res.cloudinary.com/engineering-com/image/upload/v1430070456/tips/Portal_deflection_qq0liz.pdf

Seems to tally with computer results, any thoughts?

RE: Lateral deflection estimation of portal frame

JAE's method definitely seems like the way to go. Virtual work is substantially more involved as you can't ignore the beams.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

RE: Lateral deflection estimation of portal frame

In case you aren't familiar with it, there is a good discussion of this topic in Chapter 7 of "The Seismic Design Handbook", second edition, by Farzad Naeim. He covers lateral deflection of both moment frames and braced frames.

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


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
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

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