How Trusses Work! (Structures 5-1)
2021 ж. 13 Нау.
801 281 Рет қаралды
We can combine tension and compression elements to form trusses that span further than the pieces from which they're made. Exciting stuff! We start with a cantilever and then build to a full structural span. I show you some bridge examples and also how to optimize a truss for material efficiency. Enjoy!
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.
this is what's great about KZhead, by accident you learn about something you've been observing but not really understand for years 👍
The KZhead algorithm giveth and it taketh away.
If you think you can learn about trusses in 11 minutes you are delusional.
First time viewer. Genius is the ability to teach a complicated subject clearly, simply and comprehend able to an average person. Thank you for your time and knowledge.
Thanks!
That was brilliant. I really liked how you developed this, logically, from a single tension and a single compression structure to a structure with multiple members. Thank you.
Poly Bridge leaderboards, here I come!
You explain in such a way that it is easy to understand, bravo!
As part of my job, I have to record historic bridges, both automotive and railroad. I love watching your video showing how variations on the Warren and Pratt truss bridges work.
Thank you very much!
What I learnt after a whole career in structural engineering is that most of the time no one really cares about getting even an efficient structure (unless it is the primary structure of something huge), let alone a theoretical optimum. The exception is design-and-build contractors where their profit margin depends on minimising materials, but of course they won't do that at the expense of complication, which costs "more than materials".
Is that in which country?
Also dependent on consistency of loading - no good to have an efficient design for only one use case. Efficiency of design presumes at some level a predictability of loading.
Vid came up with the algorithm while I've been studying for my Architect exams and brushing up on my structures. Just excellent explanations! VERY helpful.
Thank you so much for taking the time to make this video. I had a basic understanding of the loads involved in a truss, but some times had a hard time determining how the load was transferred through the structure. And it turns out because I was looking at it backwards. I would look at a bridge and try to figure out the load distribution by the weight of a truck sitting on it, not as the support structure resisting that load. I’m not sure if I explained that well, but your explanations helped a lot. What finally made it click, where I had that lightbulb eureka moment, was your graphics of the hands supporting the structure. I am very grateful for that, and again I appreciate you making these videos for everybody
You're welcome!
Thank you sir Very interesting especially the arches and cables you find in the efficient truss
I like how you teach visually, as it can be difficult going straight to maths without an intuitive understanding.
Paul this is such a concise and beautiful presentation! Your style works so well, like a great piece of music. Well done!
Thanks!
@@PaulKassabian 0:50 0:59 0:59 0:59 0:59 1:00 1:00 1:00 1:00 1:01 confused right abt here, sir pls help
I have designed trusses at a wood truss manufacturing plant, but never understood this. The software just did if for me. Thank You for sharing.
well explained, I think the magic in understanding it all ,is breaking it down into small thinking process blocks
wow, you demonstrate the truss concept in step by step, this is very easy to understand and truly a clever method. Thanks!
You're very welcome!
The tutorial showed up when I needed it the most. God Bless you Sir.
Just discovered this while taking a structures class, this is very helpful and easy to understand. Thankyou!
You're welcome!
Amazing explanation of TENSION & COMPRESSION using a PAPER!!!
It's so intuitive and fun when explained like this !
You're welcome!
I love just going out in the world and trying to understand things work and being able to just ask that question and get a video on it.
Great video with clear explanations!
Nice use of West Point Bridge Designer! I used that with my middle school Technology Education students for many years.
Fantastic work! Thanks Paul!
This is the most brilliant explanation of trusses I have ever seen.
Thanks!
Liked and subscribed. I am an engineer and having come across your channel by chance I found it to be be beautiful in the simplicity with which you explain things that in our days professors bored us to death with explanations of vectors and forces that in the end left us as ignorant as we were before. Thank you Paul and please continue the illuminating work. Hopefully some young blood will stick with your presentations and learn much from them, especially in the area of being opened to the enthusiasm of learning beautiful concepts.
Thanks!
I’m so friggin pumped on this channel!!!❤❤❤
Wow! The way I look at bridges is changed forever. I had to subscribe after watching this video. Thank you 👍
Great to hear!
That part about the optimization of trusses spot on
thanks - much appreciated!
Thank you for that. You bridged my understanding
Nicely explained! Brings back my Statics lectures from a few decades ago. I might have to dig my textbook...
Good idea, I'll wait...
Fantastic video thank you for explaining all the physics behind each of the different kinds of geometry that was very helpful. I’m trying to learn how to build trusses in the house and this definitely answered my questions.
best video so far for me, this is perfect for civil engineering students. more power to you sir thank you
You are most welcome
I like the way you explain. I found your approach very logical and easy to follow.
Thanks!
Excellent presentation. As a teacher I compliment you on your presentation. A good teacher takes a complicated subject and explains it in an clear and easy manner that could be understood! Kudos!
I liked his diagrams. They showed the magnitude and direction of forces in a way I could understand.
Great!
좋은 영상 감사합니다 탁월한 전달력 최고네요
Sophisticated and simple. That's brillian.
Thanks!
One thing that pop in my head is when you build a truss on the ground and you use a crane to put it in place you have to consider that forces (tension and compression) will be the opposite way temporarily while moving it! Good video sir!
Very good point!
you had me at "I'm a structural engineer"
That is brilliant ,it instigates useful ideas that can be used in truss and tie model in the design of deep beams of reinforced concrete designs
Glad it was helpful!
So simple? No, it is made simple. A simple start, add elements one by one, understand each's role, comprehend the larger complecated picture. Very fine tutorial, that neither goes above head, nor allows to forget easily! Kudos.
These videos are great for helping me throughout my apprenticeship!
Glad you like them!
excellent thanks for your work
Love this video.... Well illustrated for the beginner...
Glad to hear it!
I am a land surveyor currently doing my stage. I very much hope to work on a large world-class bridge at some point in my career. I have long loved bridges and considered them the greatest expression of Human engineering - because they link People together, they span gaps, they encourage exchange and cultural fluidity. The Ancient Roman Princeps was also the "Pontifex Maximus", the "Great Bridge-Builder". Spanning gaps is a Human fixation, it seems. There's so much glory in a great elegant bridge.
I'm less than two minutes in, but can already tell that I've just struck KZhead gold! New sub!
Thanks!
Brilliant way to explain the truss geometry... Thanks
You are welcome!
love it!!! may i ask how do you simulate bridge tension and compression?
Very basic knowledge that many people don’t know. Thanks
Nicely done ! Cheers !
You are a great teacher! Nice job with this.
Thanks!
Thank you sir. Anyone with a PHD can explain physics to other well educated people. It takes a master to explain it well to us simpletons.
Thanks!
This is a great video, do you think you could do a video on construction cranes and all the tension and compression they face? Im sure there is such a fine balance of all the techniques you have shown us thus far. I've look for years for someone to give a good explanation on the engineering behind cranes and no one has been able to do a good job. Maybe you can be the first :)
Thanks for a truly excellent presenttion of the concept of tension/compression in trusses. If only the rest of the world could employ logic as well as you engineers....
Thanks...and in this video I explain why all cafe tables, if designed by engineers, would have 3 legs not 4 and therefore not wobble! kzhead.info/sun/f72PnpiiqmSfrYU/bejne.html
Structural Engineer: uses hi NOSE to point out something Me: EVEN MORE respect
This was a great explanation. Thanks!
Great lesson thanks for this lecture
fantastic video with concept, very easily explained
Many thanks!
Great video, thank you!
You ar an amazing teacher! Thanks for sharing your knowledge. I subscribed.
Awesome, great to hear!
A wonderful video, a beautiful explanation. thank you very, very much. I am not an engineer but I enjoyed this very much. I always wondered.
Glad it was helpful!
Great informative video.
Good illistration technique
Brilliant .. God bless You !
you have a new subscriber !!!! great video !!!!
Thank you, simple and concise!
You're welcome!
this is actually pretty nice
Hey: I have been watching your video series on structures, and I would like to commend you on both the quality and content of these videos...really well done. In terms of trusses, which truss design do you favor for over all strength for uniform compression loads? Again, thank you for taking the time and effort to make the structure videos.
Thanks a lot for your awesome videos. Your style and the hints highlighted are truly enjoyable and fun to watch and learn :-) Sincerely wishing you and your KZhead channel a rapid steady growth and popularity. Kind regards :-)
Genius teaching style. Take love from Bangladesh ❤️❤️
As a structural bridge engineer, I often watch your clips and thoroughly enjoy them. You demonstrate great creativity and innovation in your work. Particularly impressive was the clip featuring an arch structure built on a small scale model, where you deformed its shape by applying load with your finger. Additionally, the clip discussing trusses was captivating, especially when you introduced the optimized truss, with one part functioning as an arch and carrying compression loads, while the other part acted as a cable and carried tension loads. Overall, your work is truly amazing. Thank you for creating such incredibly beautiful clips.
Thanks!
Paul could you teach please what would be the best structure to support a second floor of a 15 meter stadium grandstand without beam
Wow. Thank you so much. Inspiring.
Glad you enjoyed it!
God bless a true educator! Paul just found your lessons when you trusses lesson came along my feed. I'm 47 big old goof who only took physics for dummies in college and nothing ever in high school. This is so very interesting and well presented. So very well done Paul, thank you. I can't wait to get to your other content. And watch this one on trusses again.
Thanks and more to come!
Well done, but how do you calculate the load a truss can safely support?
հրաշալի աշխատանք
Amazing teacher!
Thank you! 😃
10:40 ❤ “when you have a limited situation or something you can control, you are able to optimize more”
Awesome explanation !!!
Glad you liked it!
Great explanation! Thank you!!!
You're very welcome!
Thanks from Spain
Hello Paul, I’ve been trying to find the right definition or rather the exact difference between a beam and a girder, I am a marine engineer so I deal with beams and girders on a daily basis, but I find them structurally very similar so it would be great if you could help me break down their fundamentals….. Thanks for the videos… keep them coming!
Beams and girders are not different, girders are just bigger. Girders are just beams that other beams frame into.
Correct - they behave the same way under load...it's us that use words to describe them. quarrydawg is right that, for those who use them often, beams typically frame into girders and that relates to their use. Now let's talk about joists....
UÁU !. Inglish Is not my original idiom, but, any way, I can say your class was realy wonderfool!!! ( from Argentina).
շնորհակալություն Paul!
You're welcome!
Good day. What about vierendeel truss? Do you have a video explaining how it's work?
Question for you; when I see roof trusses that are exposed as in a large warehouse type building why is it that the trusses don't always span the entire width of the roof? The last triangle just seems to float out there, wouldn't it make more sense to have the final triangle anchor into the bearing wall? Or is it really not necessary? Thank you, you are great teacher.
I'd like to see a program on R. Buckminster Fuller's Octet Truss, which he claimed was the most efficient truss possible.
Excellent Poly Bridge 2 tutorial.
Correct - that's the only reason I made this video...
@@PaulKassabian It also happens to be a really informative and accessible video for those who want to learn more about structural engineering.
you are awesome i hope i learn more from you thanks a lot
You're welcome! More to come...
I once made a small truss bridge for my daughter's cat. It was made of 1/4" x 3/4" pieces of white pine . Finished size was about 8 feet long and 6" x 6" square.. It was held together with hot melt glue. Imagine my surprise when we tested it's actual strength. It would hold two 90lb. bags of concrete!
Heyy....do you have a video on how to make structural models of truss bridges?
this is great.
First time seeing your channel and I already truss you very much! Will search your channel in hopes to find any videos on tensegrity, if you haven't done any would you please consider sharing what you understand of tensegrity principles?
I'll add tensegrity to the list!
@@PaulKassabian Thank you so much!!
I know this is a late comment, but this explained it well, thanks Paul.
3:12 the best explanation , ever, on youtube !
Last Truss can be further modified for looks i.e. unequal members forming trapezoids 🔰💎 to equal members forming squares 🧇🔶
now , i am a structural engineer !
3:35 “you have to truss me on this”, well played
This might actually help me finish all those bridge building games I own ^^"
The blue ones if you look at them from a front view rather than side view is that they are usually made with "X" webbing along their length . Is this to reduce the weight of the these? I work with model railroading & I have some Truss bridges that are on my layout.