4. Suspension Bridges

How do suspension bridges work? Watch this video to learn how these elegant and efficient structures can carry heavy loads. (Note that the Arthur Ravenel Jr Bridge at 6:25 is in fact a cable-stayed bridge, not a suspension bridge, and it should have been synchronized with the words spoken at 6:30.) Don't forget to "like" our video!
To learn more and to see additional models, go to www.civil.uwaterloo.ca/brodlan....
You might also like our Beam Bending videos at • 01) Strain in a Beam
And our statistics videos at / @easystats8758

[@marksmithwas12]

I feel like these videos are preparation for people wanting to play the Bridge Constructor games

[@timothyholman4301]

Marksmithwas12 thats why im watching them...i always did triangles...but now i have the power of knowledge on my side...i still wont get far tho

[@stevx007]

yes polybridge hahaha

[@HyTricksyy]

I'm taking notes for poly bridge, ngl

[@Jack-tu5zf]

This is really useful for polybridge

[@overinfinity0206]

PolyBridge 2

[@parwes540]

Having watched so much Aliensrock polybridge that this gets recommended to me

[@DylanJHewitsonBevis]

me

[@konekoray9323]

Same. I still to this day get irked by his under-utilization of tension systems, even in situations where they would work well and for super cheap. But instead of a simple tension system to evenly distribute the loads, he just brute forces it with his "muscles".

[@letroll8954]

@@konekoray9323 the legendary quint muscle is peak design

[@TomasTots]

Same

[@louispalko691]

Lol yup

[@Dumbassfish63]

Polybridge players: **Quick quick, Write that down, Write that down**

[@brandonbertelsmeyer5713]

Fr though

[@kirolloshalim5417]

You're a pro if you know a lot about statics and dynamics.

[@giovannicorbarigasparini5352]

Not even here can I escape from the Tacoma Bridge example.

[@sethhu20]

isn't that caused by resonance, mainly?

[@kosskrit]

@@sethhu20 Exactly what I wanted to point out. It was caused by wind, which hit too thick sides of the bridge deck in a way, that it caused bridge to resonate at its natural frequency.

[@vusimahlobo5378]

I think the video spoke about flexing

[@leonardoquispe6178]

Is this a poly bridge tutorial? :)

[@kenx00x]

yup

[@ayaanpatel4477]

for sure

[@seannotshawnorshaun_8126]

for sure

[@Soverthe]

for sure

[@shaafalikhan3704]

for sure

[@empanada65]

Bridges are hammocks. Got it

[@jimmyawesome2338]

engineering is just a giant siesta

[@eugeneschulte4950]

No. The bridge is NOT the hammock. The hammocks are like the suspension support cables. Its the support cables that hold up the roadway or THE BRIDGE.

[@TheEgg185]

I have nothing of importance to contribute to this discussion.

[@Chernosjk]

You're not alone

[@chatter2765]

Exactly. But hey, we're here to learn. Let the teachers talk.

[@webgpu]

i am firmly inclined to agree with you based on the lack of my knowledge about this subject.

[@DanteYewToob]

I have no witty retort, silly meme, or reference from the video to respond with. This timestamp references nothing; 0:00 enjoy. Or dont.

[@RexGalilae]

The chick in the video is fine tho

[@andremoreau8390]

Told me exactly what I wanted to know.

[@AsiccAP]

nah use falling roads

[@popularairtravel2905]

Great video, friend! There are times when nothing better illuminates your path than a burning bridge. Enjoy your travels and good mood!

[@anil4015]

Thank you for explaining in very simple terms. I appreciate the engineers who make it possible.

[@hartfordboothe7466]

This is a neat video which gives the basic principals of suspension bridges well, I feel. I am building a private pedestrian bridge and some *basic* information helps me place/understand the more complex information I need to digest to be able to design it well. Thanks for the time and effort to put this together.

[@armandmatossian2081]

This is fantastic content. I'm so happy I found this channel. Excellent animations.

[@renzluislomugdang1315]

Someday, i will have my own suspension bridge design that will be iconic in the world. 😁🔥

[@ivanbiscuit6924]

God tier ambition, massive props

[@TheSpringRain-yi8vx]

This channel is amazing, two thumbs up for u a special work❣

[@N1CKSKILL]

Play PollyBridge. Awesome little bridge engineering game. Great videos!

[@mineman2142]

i was just thinking "wouldnt it be awesome to see them play polybridge

[@yoavmor9002]

Pollybridge is more than engineering. It's about being resourceful and thinking using wacky solutions to solve problems.

[@OneDirection2V]

hahaha please tell me this is a joke

[@incognitoburrito6020]

@@OneDirection2V What?

[@bufuhl1869]

now i'm gonna be a poly bridge pro, thanks

[@auxencefromont1989]

You should check the episode on chains and arch

[@daved3494]

Brilliant, and fascinating, as usual. Thank you.

[@denizucer578]

Thanks for sharing for free. Very valuable content.

[@sarqramirez4375]

Thank you for explaining in very simple words.

[@user-th3ib9nt4b]

Am so happy for seeing this video These video is like preparation for people wanting to play the bridge construction Fantastic

[@akbarpratama2500]

Thanks, Inca civilization. You have showed us the sustainable suspension bridge!

[@Oscarandu]

This video makes me want to know more about geometria and maths, and THAT is a big deal Amazing

[@axel_x8954]

First time that i saw 25 abril bridge instead of golden gate bridge as an example 😊👍👍

[@AbhishekYadav-ci3ht]

Amazing ❤️ I never Saw such amazing explanation

[@hannayapelekai1628]

Well done! Very nice video to fall asleep to, thank you

[@shannons1886]

This was amazing! I learned so much, so quickly!

[@serpentry2780]

Nice video me and my son learned a lot thank you!

[@thakursaab4050]

fantastic content, exactly what i wanted to learn

[@soumitrovyapari8522]

Thank you Sir and Mam for this educational video. Hope the series of videos continue !

[@SwissTrippin]

Great simplification for architects. We need more of these videos.

[@Supermario0727]

Architects don't know these things.

[@freakazoid4691]

@@Supermario0727 Architects know surprisingly little to be honest.

[@Natte_Voeg]

6:23 the Arthur Ravenel bridge is a cable-stayed bridge.... not a suspension bridge... the transmission of force is very different.

[@minhtrido969]

Half volle yoghurt He’s talking about the invention of other cable bridge after the suspension one, but thanks for pointed it out

[@riksaboi9792]

Ok NERDS

[@alexeysaranchev6118]

@@riksaboi9792 That's a very weird YT channel to call anyone nerds on.

[@floatingturd3510]

The bridge is being SUSPENDED by cables, so it is a suspension bridge, but I prefer to give it my own name. Arthur Ravenel states in chapter two off his book, guide to suspension.

[@turkeybowlwinkle4440]

I noticed that too. A cable-stayed bridge is not a suspension bridge.

[@Alex-fp2gw]

Really nice work. Though i am unsure that the Tacoma Narrows bridge collapsed because of the flexbility of its components (it may just be a simplification) but rather because the components, that were very solid, had a resonnance frequence that matched that of the wind at the time it broke. This causes the vibrations to increase violently passinf through the bridge, causing the collapse. Usually, engineers select materials with resonnace frequences far away from the ones the building might encounter in nature (wether for sismic waves, of even wind...)

[@frankfronczak4469]

It appears to be a common misconception (or grossly oversimplification) that the " frequency" of the wind was the same as a resonant frequency of the Takoma Narrows bridge and that this led to the bridge's failure. The actual cause of the failure was somewhat more complex and due to aeroelastic instability. A relatively constant velocity wind caused the bridge deck to deflect (both laterally as well as, more importantly, torsionally). This twisting generated aerodynamic lift caused by the "angle of attack" of the bridge deck changing. This lift caused further torsional deflection further increasing the angle of attack, thus generating even more lift. Eventually the angle of attack reached the point where aerodynamic stall occurred, resulting in a loss of aerodynamic lift and thus causing the deck to move down towards its equilibrium/neutral position. However, because of inertia, it moves past its neutral position, and continues downward resulting in a negative angle of attack, and the resulting generation of a downward aerodynamic force on the deck of the bridge. This twisting can be clearly seen in the video. As the negative angle of attack increases, it once again reaches its stall point, and the downward aerodynamic force is lost. The forces due to the elasticity of the bridge structure now pull the deck back up to its equilibrium position and the process goes on and on. So, a steady wind that can exert sufficient lateral force (with consequent twisting and consequent lifting (positive or negative) force) so that the stall angle of attack is reached is what caused the bridge vibration amplitude to reach sufficient levels that caused it to structurally fail. This is a somewhat simplified explanation of how the (relatively steady) wind caused the bridge failure.

[@wassunoor8678]

This was an amazing lecture. Keep em coming

[@MathWars]

Excellent explanation. Thanks a lot

[@lucasgrigoriu6406]

plays poly bridge once

[@OneDirection2V]

ive been wondering about this for quite a long time

[@atulimakvana1092]

Very nice video with better content. Thank you for uploading,...

[@puppzogg]

these videos are just simply intuitive

[@user-sz4dm6te5d]

Весьма познавательно, благодарю!

[@armadillito]

I think you've given this video the description of the previous.

[@engineeringmodels]

Thanks for spotting this oversight. I will correct it today.

[@knyt0]

@@engineeringmodels a lil' late

[@silverseven5283]

Love it! I enjoyed your videos! I Subbed you! You are very clear, easy to understand, super informative, and the explanation are not intimidating to beginner like me. Please please please keep up the good work!!!

[@user-wh2tn2yh7c]

It's a beautiful site to behold

[@jimmywu2296]

Great video with great explanation! Thank you for uploading!

[@alim7532]

this was a juicy video for me as a first year building engineer

[@rajeevsorokhaibam1450]

i have always needed a practical way of learning and I think i just found it. Thank You for this and we hope you continue to do so .

[@makara6192]

Best channel. Great job guys

[@Raffleseducationcorp]

Thank you for making this video 👍👍👍

[@matiasfernandez8083]

Awesome video! i just dont understand where the horizontal force is coming from is the vertical force y already supporting the whole weight of the bridge. I thought the weight was distributed between the two forces...

[@jaikiratsingh4379]

Thanks for the video ❤️

[@RobertLock1978]

Nice channel.... thanks for uploading these.

[@arsalanarya]

It was awesome. Thanks.

[@civilengineer5064]

I appreciate you work! That's really a great content keep it up!

[@tutstorial8474]

do you have a video deriving the eqns / formulas used to analyse suspension bridges? 😁

[@donfrancis1246]

Thank you for this amazing video

[@aaronharding3695]

my only question is that when you introduce the suspenders, do you not change the tension on the main cables? doesn't this distort the whole model? like how one suspender could be tenser than it's neighbouring suspender?

[@FranciscoSilva-vb3bj]

Cool!! A PolyBridges tutorial!!!!

[@fooxik70]

i love that poly bridge tutorial

[@MarkeziProducer]

amazing video.

[@shibanjandutta3213]

Please do make such a video for cantilever bridges also

[@SystemBD]

These engineering videos are great. No _suspension_ of disbelief is required.

[@xhabaftiadvan68]

Keep doing this good job

[@bradzepfan]

very very well done sirs! can one purchase those bridge models anywhere?

[@jenandamra7869]

Thanks for making civil engineering and structural systems much more understandable as an architect

[@MDP1702]

@@_blank-_ No, no. He's going to "renovate" it.

[@HeroValios]

Correct me if I'm wrong - but wasn't the Tacoma bridge AKA Galloping Gurdy like that as a result of the exact opposite issue you described? If memory serves, it galloped and eventually broke not because the materials they used were too flexible, but because they were too rigid, causing the wind whipping past to resonate into enormous waves of energy forcing themselves through components that ordinarily shouldn't have give - thus leading to the eventual structural collapse. Admittedly, it's been some time since I reviewed that material.

[@somedude6833]

arent they good too because tension is carried equally in the ropes/cables?

[@chandarprakashgangawat3168]

Nice video sir .

[@kulaklan5452]

This really helped me because I am supposed to make a bridge for my school project

[@xxbondsxx]

This channel is great!!

[@qistinaaneesarastam6727]

thank you for the enlightenment !

[@dillmon1]

The video only mentions the total horizontal and vertical component at each end of the cable. The video should also mention that along the length of the cable the horizontal component of the force is constant, and the vertical component changes according to the delta of the angle.

[@MasterCivilEngineering]

Step by step video solutions of civil engineering questions

[@michaelggriffiths]

Brilliant!

[@mato9684]

Very enlightening video, thanks

[@mako1448mako]

is the horizontal force from the tension created from the torque from gravity?

[@user-pr9dt9fe7h]

very good videos

[@JustAPersonWhoComments]

A suspension bridge carries vertical loads through curved cables in tension. These loads are transferred both to the towers, which carry them by vertical compression to the ground, and to the anchorages, which must resist the inward and sometimes vertical pull of the cables.

[@babarbashagopavaram3458]

Really perfect for the amateur people interested in these kinds. Good work team

[@radiationpony8449]

how are you figuring the vector angle since cables aren't straight and instead follow hyperbolic curves

[@devoliukas7108]

This is so much better than physics class

[@danstankay7429]

Nice video. Great work. Cool explanation, very composed and well deatailed. Btw am a Engineering student if my lecturer stopped stoning, he would sound like you and I would be in the best college :)

[@figloalds]

I don't know how I ended up here, but I liked it 🤷‍♀️

[@woodencart3662]

Ah yes, I love poly bridge

[@PeterSodhi]

Magnificent

[@theotherside931]

*This is educational. Thanks.*

[@user-mj3ej6ze7d]

Thank you ❤❤❤

[@syedrafiqkazim448]

If you were to talk about the Tacoma Bridge I think it would fit in a video about resonance and resonant frequency better.

[@jakethesnake6783]

Polybridge 3 looks great

[@lavapototo4368]

The graphics are very realistic

[@shirshzibbu330]

now I know what to binge watch this weekend

[@igorbonaparte5414]

What materials do you use for the model?

[@Equinox121]

KZbin at 4 am: Here watch this Me after watching: fuck yeah science

[@thermatdavis2300]

Where can I get these materials used to build the suspension bridge? I need them for my project

[@educationworldmini9833]

## nice one ##

[@simulationmedia2770]

good job

[@zacharyrocks1]

The narrows bridge did not fail as a result of deck flexibility. It was due to vibrational resonance between the deck and wind. Due to the construction of the road, oscillating vortices formed on top of the road, causing the vibrations.

[@nickhenman7549]

True, but the reason why those oscillations formed was because of the flexibility of the bridges design. If the bridge had a different flexibility spectrum, the those wind induced oscillation wouldn’t have been able to resonate with the bridges limits.

[@thiagoennes]

such a cool channel! :)

[@robertromero8692]

A couple of comments: The horizontal force component would be the cosine of the angle of the force vector times the force vector, and the vertical component would be the sin of the angle. Also, the failure of the Tacoma Narrows bridge wasn't simply due to a lack of rigidity, but because a proper dynamic analysis wasn't done. The bridge experienced increasing oscillations from the wind due to the excitation of its resonance frequency.

[@robinandthedog]

I've been enjoying your video, thanks. The mean reason watching is that I have to cross the 25 Avril bridge in Lisbon sometimes. My main question is how do you keep a bridge so old safe?

[@emrage]

Great vid but don't just assume w/2 for vertical components if angles on both sides are different..

[@yantejeda2039]

The thing is, you wanna make it so the angles are exactly the same on both sides. Maybe on a hamac this doesn't happen, but on a real bridge you 100% want to do that

[@dineshbasnet7288]

very interesting sir, Now I hope I can make suspension bridge and I hope I can put it on observation event of my school.

[@Xautraisuydet]

Thank you