How Trusses Work! (Structures 5-1)

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.

[@timclark7478]

this is what's great about KZbin, by accident you learn about something you've been observing but not really understand for years 👍

[@joeb4142]

The KZbin algorithm giveth and it taketh away.

[@glichasasha750]

If you think you can learn about trusses in 11 minutes you are delusional.

[@Ennar]

Poly Bridge leaderboards, here I come!

[@howitstartsmm]

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.

[@PaulKassabian]

Thanks!

[@daved3494]

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.

[@robtristram8395]

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".

[@luiscobos123]

Is that in which country?

[@cameronlapp9306]

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.

[@burklander3338]

You explain in such a way that it is easy to understand, bravo!

[@goldonon]

Thank you sir Very interesting especially the arches and cables you find in the efficient truss

[@stevenkamp8001]

well explained, I think the magic in understanding it all ,is breaking it down into small thinking process blocks

[@kasirk7945]

The tutorial showed up when I needed it the most. God Bless you Sir.

[@TRON0314]

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.

[@dulcedelgado8594]

Great video with clear explanations!

[@michaelyano6094]

Fantastic work! Thanks Paul!

[@jeremiahbarlow1924]

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.

[@jimmimak]

I like how you teach visually, as it can be difficult going straight to maths without an intuitive understanding.

[@cojoe4896]

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.

[@nikeshrathod7698]

Amazing explanation of TENSION & COMPRESSION using a PAPER!!!

[@KF1]

you had me at "I'm a structural engineer"

[@Flurib690]

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

[@PaulKassabian]

You're welcome!

[@dalegray934]

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.

[@PaulKassabian]

Thank you very much!

[@ArtworkAnon]

I’m so friggin pumped on this channel!!!❤❤❤

[@michaelmacdonald2907]

Thank you for that. You bridged my understanding

[@CMRHM]

wow, you demonstrate the truss concept in step by step, this is very easy to understand and truly a clever method. Thanks!

[@PaulKassabian]

You're very welcome!

[@nicolasramirez3944]

Paul this is such a concise and beautiful presentation! Your style works so well, like a great piece of music. Well done!

[@PaulKassabian]

Thanks!

[@dopenaidoo1359]

​@@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

[@elektrolyte]

Structural Engineer: uses hi NOSE to point out something Me: EVEN MORE respect

[@lucianolizana446]

It's so intuitive and fun when explained like this !

[@PaulKassabian]

You're welcome!

[@mmawad100]

excellent thanks for your work

[@BackToReality]

I'm less than two minutes in, but can already tell that I've just struck KZbin gold! New sub!

[@PaulKassabian]

Thanks!

[@bullfrogpondshop3179]

Nice use of West Point Bridge Designer! I used that with my middle school Technology Education students for many years.

[@kushanimehta9325]

Just discovered this while taking a structures class, this is very helpful and easy to understand. Thankyou!

[@PaulKassabian]

You're welcome!

[@ssmith2019]

Nicely done ! Cheers !

[@SheeneP]

좋은 영상 감사합니다 탁월한 전달력 최고네요

[@daviddavid-ow2ys]

Great video, thank you!

[@kishfoo]

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.

[@PaulKassabian]

Thanks!

[@adventure-cowboy]

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.

[@ffstructures]

Brilliant .. God bless You !

[@martingagnon4547]

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!

[@PaulKassabian]

Very good point!

[@csidun9087]

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!

[@user-di4bt7qu2i]

This was a great explanation. Thanks!

[@flourishomotola5306]

This is the most brilliant explanation of trusses I have ever seen.

[@PaulKassabian]

Thanks!

[@Uswesi1527]

Very basic knowledge that many people don’t know. Thanks

[@ShahroozAryan-ez7cc]

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.

[@PaulKassabian]

Thanks!

[@HarshRajAlwaysfree]

this is actually pretty nice

[@gaetanomontante5161]

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.

[@PaulKassabian]

Thanks!

[@lshepherd5859]

now , i am a structural engineer !

[@mohammedjassim1360]

Great lesson thanks for this lecture

[@iliyakhramov4381]

Sophisticated and simple. That's brillian.

[@PaulKassabian]

Thanks!

[@503dude8]

Wow! The way I look at bridges is changed forever. I had to subscribe after watching this video. Thank you 👍

[@PaulKassabian]

Great to hear!

[@bartvrhijn]

That part about the optimization of trusses spot on

[@PaulKassabian]

thanks - much appreciated!

[@janninoenecio78]

best video so far for me, this is perfect for civil engineering students. more power to you sir thank you

[@PaulKassabian]

You are most welcome

[@TheMDJ2000]

Nicely explained! Brings back my Statics lectures from a few decades ago. I might have to dig my textbook...

[@PaulKassabian]

Good idea, I'll wait...

[@jiojetigarea7176]

Love this video.... Well illustrated for the beginner...

[@PaulKassabian]

Glad to hear it!

[@pabloetchepare7160]

you have a new subscriber !!!! great video !!!!

[@PratyushTewari]

10:40 ❤ “when you have a limited situation or something you can control, you are able to optimize more”

[@mitchdevarennes1337]

Great informative video.

[@hugodesrosiers-plaisance3156]

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.

[@yemanemelkamu5682]

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

[@PaulKassabian]

Glad it was helpful!

[@mujtabaahmadi7960]

I like the way you explain. I found your approach very logical and easy to follow.

[@PaulKassabian]

Thanks!

[@albertopilaalonso6291]

Thanks from Spain

[@ammarabid2077]

3:35 “you have to truss me on this”, well played

[@bobvar72]

You are a great teacher! Nice job with this.

[@PaulKassabian]

Thanks!

[@raiderfandew]

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!

[@simplesapiens9858]

this is great.

[@bftfcfua2946]

Good illistration technique

[@user-kk2nl2os5h]

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.

[@rodneytrotter1427]

These videos are great for helping me throughout my apprenticeship!

[@PaulKassabian]

Glad you like them!

[@faisalrasheed3616]

Brilliant way to explain the truss geometry... Thanks

[@PaulKassabian]

You are welcome!

[@jamieholtsclaw2305]

I liked his diagrams. They showed the magnitude and direction of forces in a way I could understand.

[@PaulKassabian]

Great!

[@planetaryutilities]

Thank you, simple and concise!

[@PaulKassabian]

You're welcome!

[@dreamdream8942]

Genius teaching style. Take love from Bangladesh ❤️❤️

[@sanjayyadav-hj7dd]

fantastic video with concept, very easily explained

[@PaulKassabian]

Many thanks!

[@fern8580]

3:12 the best explanation , ever, on youtube !

[@narekantonyan2264]

հրաշալի աշխատանք

[@nimnogaparus]

Amazing teacher!

[@PaulKassabian]

Thank you! 😃

[@shahaaa]

Great explanation! Thank you!!!

[@PaulKassabian]

You're very welcome!

[@Borishal]

Wow. Thank you so much. Inspiring.

[@PaulKassabian]

Glad you enjoyed it!

[@thecasualengineer99]

I know this is a late comment, but this explained it well, thanks Paul.

[@AlxGontijo]

Awesome explanation !!!

[@PaulKassabian]

Glad you liked it!

[@charlesbromberick4247]

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....

[@PaulKassabian]

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! kzbin.info/www/bejne/goq5n2egqJecsK8

[@ragas2845]

You ar an amazing teacher! Thanks for sharing your knowledge. I subscribed.

[@PaulKassabian]

Awesome, great to hear!

[@jimhagler3716]

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.

[@PaulKassabian]

Glad it was helpful!

[@tdz]

Fantastic!

[@PaulKassabian]

Thanks Tim!

[@beduino19502010]

UÁU !. Inglish Is not my original idiom, but, any way, I can say your class was realy wonderfool!!! ( from Argentina).

[@vsergeiev]

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 KZbin channel a rapid steady growth and popularity. Kind regards :-)

[@muwanguzidawudi8328]

Thank you

[@Micropterus06]

շնորհակալություն Paul!

[@PaulKassabian]

You're welcome!

[@HorzaPanda]

This might actually help me finish all those bridge building games I own ^^"

[@RG-ru3ux]

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.

[@starskeymaid]

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.

[@PaulKassabian]

Thanks and more to come!

[@JonathanJournal]

love it!!! may i ask how do you simulate bridge tension and compression?

[@BostonMark]

Beautiful

[@bouzoukistudent8180]

by mistake i finaly found a worthy channel .

[@ongsengtikhak953]

I dropped out of engineering college because I couldn't understand or imagine in my head,this particular topic.. only if teacher like you could have changed everything.. again thank you for the upload 🙏

[@PaulKassabian]

You are most welcome!

[@llucruizesteve5949]

Soo good!!!!

[@PaulKassabian]

thanks! Do keep watching!

[@etno2010]

thanks... ...bridge builder game...very good for that...

[@AbdulHafeez-cq6oo]

Great description

[@PaulKassabian]

Thanks!

[@kalpeshwani8520]

Last Truss can be further modified for looks i.e. unequal members forming trapezoids 🔰💎 to equal members forming squares 🧇🔶

[@mateuszmostowski9546]

Truss him guys, he's an engineer!

[@HarshRajAlwaysfree]

you are awesome i hope i learn more from you thanks a lot

[@PaulKassabian]

You're welcome! More to come...

[@gaveintothedarkness]

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 :)

[@ser7ser7i]

Çok iyi, teşekkür ederim.