How Frames Work! (Structures 7-1)

We’ve made it! We’re here to discuss frames…we had cables, arches, columns, trusses, beams. Now we’re going to take those beams and columns and join them together to form a frame. They may not be structurally efficient, as they take loads in bending, but they are efficient for what we need structures to do for us. Frames are boxy but helpful!
I'm Paul Kassabian. I'm a structural engineer and a Principal at SGH in Boston, MA. I taught graduate students at MIT for nine years and currently teach on/off at Harvard's Graduate School of Design (GSD). These are videos based on my years of teaching structures to students.

[@crayx48]

I work in an institution for kids to spend their free afternoons. I regularly build wooden huts with the visiting kids. Thank you very much for your easy to follow yet immensly informative videos on structures. It is a great thing to have that info in my head at work :)

[@PaulKassabian]

That’s great!

[@musca8803]

"Everything should be made as simple as possible, but not simpler." This famous sentence well describes your videos: cause and effect related in the most direct way. Thank you!

[@PaulKassabian]

thank you!

[@murtazamahemud2459]

The best series for beginner students of structural engineering.

[@dave618034]

Just a quick note to say that I, as a septuagenarian appreciate your delivery, in plain English as it were. I wish all tutors had your approach. The world would be a smarter place.

[@PaulKassabian]

Thanks!

[@delayedgratification581]

Great explanation! I wish KZbin existed when I went to college like 20 years ago 😢

[@nicolasramirez3944]

Wow I love the idea of bending moment as related to the distance from the thrust line/force form!! Something great to think about. Thank you!

[@PaulKassabian]

You're welcome!

[@PeterDebney]

The thrust-line approach is an excellent way to understand how frames work, and something that my lecturers never mentioned (unless I missed that class - entirely possible…). Today an engineer would just build an FEA model of the truss frame of the exhibition building. Also analysing using a thrust line gives a great way to check the results, especially as the curved nature does not allow it to be checked using Kleinlogal equations.

[@PaulKassabian]

Thanks Peter!

[@qasimalibadi1302]

Your explanation very organized & and professional

[@utkarshgoel7873]

I haven't seen such a explanation on thrust line before ❤ Y are the genius

[@PaulKassabian]

Glad you liked it!

[@alianjohnson6035]

thanks so much for presenting these videos. you truly have an great ability to distill complex concepts into beautifully presented information. i only discovered your videos last week and have started to work my way through them. cheers from Australia.

[@PaulKassabian]

You're very welcome!

[@Jam555s]

Good to see new Videos, Thanks

[@HeJurm]

Your videos really have peaked my interest in structural design: it is not just about building codes and structural analysis! I had a question about pre-stressing tendon profiles in you pre-stressing video. Is there a source which could help me examine effects of different tendon profiles? Is there any reason to pre-stress arch-structures?

[@user-sh5dr8op3n]

Best video for architects to understand the complex structure without equations! Appreciated for sharing these knowledge and experience Paul:)

[@PaulKassabian]

Thanks!

[@iceman7298]

Your vids are amazing, we need more.

[@PaulKassabian]

More to come!

[@roel1778]

This has been a fantastic course! Thank you. Are there handouts available?

[@utkarshgoel7873]

Paul sirr, I like yu methodology to look at the concept, it's marvelous Y have shown an Arch section fracturing at two sections which is completely infeasible Arch concept comes from Key stone at the crown and the spandrel support on either side with supporting stones compressing each other just like a 📌. So separation cannot take place when stones are splitted with their faces matched

[@padmanabhapai6395]

Thank you very much for these short lectures! I have 're-learnt' many topics correctly. Is there any good book you recommend to dig deeper? Especially on domes, thrust lines & Frames?

[@rekng1634]

The best!

[@maastructureconsultancy4554]

thanks for Maa Structure & Consultancy

[@dlv5]

Can u make video about wind load or pressure on shape, what shape best for in high place and how reduce wind load, thanks before😊

[@ahmedyaqub2377]

hello, how to allow partition wall heads to expand and contract with the movement of the steel structure?

[@sakilhasanmollah]

Sir big listner to your. Could you deliver a speech about some structural modelling software? Regards Sakil Hasan( persuing M.Tech, Structural Engineering

[@jamildrareni4304]

You got me addicted to structural engineering! one silly question...I thought that a structure shouldn't exist outside of the thrust line and here we have a frame with thrust "triangle" that lives outside the frame !!??

[@PaulKassabian]

Sure - when the thrustline is outside of the structure then the material has to carry that in bending. The further out the thrustline, the larger the bending moment.

[@jamildrareni4304]

@@PaulKassabian aah! I just got a bulb moment!! Thrustline must follow the shape and shape must follow thrust line. If the first case is not met then the shape must deform/bend to contain the thrust line.

[@mohammedlasmi649]

Thanks too much for the explanation

[@MiffyNichen]

Thank you very much for the great explanations.... I haven't learned what is the thrust line when I was a student (my major was electrical engineering). How is that related to bending moment and shear stress? Is there a formula to calculate thrust line? Anyway, thank you very much again!

[@PaulKassabian]

A thrustline is the shape a cable would take for the same loads. Then bending moment is whenever he thrustline is away from the centroid of the structure. My earlier videos on cables and arches explain it from a conceptual approach...and glad you liked it!

[@MiffyNichen]

Thank you very much for the explanation!

[@designstudio8013]

When the load moves from compression or tension to bending.@@PaulKassabian

[@krunalrudani]

Respected, All assumption and conclusion and also output results When weight to strength, cross section , density of material constant and same Please clarify and update us

[@KF1]

Is the distance factor of bending moment similar to the length of compression members? Square factor?

[@PaulKassabian]

good question! The bending moment is linear with distance of the thrustline to the centroid of the structure.

[@KF1]

@@PaulKassabian I think I understand. Thanks!

[@mohammedlasmi649]

Thanks too much

[@abdullahadel9716]

the best

[@bonifaceogutu6860]

Yo our presentation is a notch high thanks for this insight

[@HHHPedigrees]

Why are you not a professor?

[@PaulKassabian]

I teach part-time...I used to teach grad students at MIT, then at Harvard GSD...