SA44: Analysis of a Building Frame using the Slope-Deflection Method

[@engm.h.s2184]

Exceptionally brilliant way in teaching. Many thanks!

[@juangabriel4173]

Simplemente hermoso video I love dr structure the best!!!!

[@kumratana9960]

So amazing tutorial video

[@king0vdarkness]

If, @ 4:02, there was a load at the end would you consider it as a canilever? Also, would this then affect the rest of the calculations? Thanks for the video! :)

[@DrStructure]

Yes, the frame has a cantilever segment. A load placed on that segment does affect the rest of the calculations. In such a case, we could either expand the slope-deflection formulation by viewing the cantilever segment as one of the beam segments, or we can transfer the load(s) placed on the cantilever to joint C, then remove the segment as is done in the video before analyzing the frame. Suppose a downward load of 10 kN is being applied at the free-end of the cantilever. Since the length of the segment is 3.25 m, the applied load causes a clockwise bending moment of (10x3.25) 32.5 kN-m, and a downward force of 10 kN to develop at joint C. So, we simply replace the cantilever segment (along with the applied 10 kN load) with a clockwise moment of 32.5 kN-m and a downward force of 10 kN at C, then proceed with the analysis. Naturally, these two forces at C affect the results of the analysis.

[@king0vdarkness]

@@DrStructure thanks for your detailed reply, that helps a lot! :) I have subscribed as your videos are great! Btw If you're ever in need of any voice actors, for your videos, please let me know.

[@HariPrasad-ox5ri]

Can we take the point loads as a udl and go on further?

[@DrStructure]

Yes, in this case the concentrated loads can be replaced by an equivalent distributed load.

[@bhupeshpant1935]

Sir please also make videos on matrix method to solve building frame

[@Mr.P539]

very informative :)

[@moirafedrick9767]

Awesome

[@franccyacutvr5611]

Thanks

[@klarizespinosa5874]

thank you for this :)

[@tijanabeuc9712]

Do you deem that is a mistake if we show shear diagram like linear instead of saltation because concentrated loads are close to each other? Moment diagram is similar now and it looks like parabolic shift.

[@DrStructure]

Yes, we can approximate the series of concentrated loads with a uniformly distributed load. That would somewhat simplify our calculations without significantly changing the results.

[@marrycyrus6305]

Nice Video

[@king0vdarkness]

How come there is no deflection or delta value at C? Is it assumed that there is no delta value for this problem?

[@DrStructure]

Yes, we are assuming that vertical and horizontal displacements are negligible in the frame. When analyzing a frame with *multiple* non-negligible displacements, the matrix displacement method works better than the slope-deflection method.

[@king0vdarkness]

@@DrStructure thanks for your reply! So, let's say we take my example of an end load of 10kN and your same load at BC. However, we also look at the deflections. How would C deflect? I'm thinking BC will curve like a U, at the end the 10kN load would also curve down. However at C I'm not sure if the beam would move down due to these external forces or remain stationary due to the final angled fixed member CE which I think would restrict the deflection at C. Please may I ask your thoughts on this?

[@DrStructure]

@@king0vdarkness Correct, the shape/geometry of the frame restricts displacement at B and C. Under that loading case, BC does bend downward (concave up) while the overhang segment takes a concave down shape with the very end of the segment deflecting downward. Although joints B and C end up having very small (insignificant) vertical and horizontal displacements, for all practical purposes, we can assume they are zero. This image (lab101.space/QA/SA44-frame-1-deflection.jpg ) shows the exaggerated deformed shape of the frame under the assumed applied loads.

[@king0vdarkness]

@@DrStructure thank you so much. You are not only a great teacher but you take the time to answer my questions with great depth! I really appreciate your time and help. :)

[@DrStructure]

@@king0vdarkness You're welcome.

[@leizeljeanmission5924]

Hello, new subscriber here. Your videos are very informative and engaging. In this video, what software did you use to create the animation? Thank you for your efforts, God bless always! 💓

[@DrStructure]

Thank you for your feedback. The 3D model was created and animated using SketchUP. The writings were done in Adobe Illustrator, and the entire video put together using Camtasia Studio.