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".
@@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.
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.
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.
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...)
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.
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!!!
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.
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.
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.
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.
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.
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 :)
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.
Yes TH-cam, I saw the "Chain and Arcs" video because you recommended it as well, doesn't mean I'm enjoying them, so please stop. And yes, I will watch this one as well...
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...
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?
There is a country where all the regions have the same language, culture, and laws. In another country, different regions have different languages, cultures, and laws. For the citizen of the first country, it would be easier to travel from one region to another because the person will not have to deal with new things. The same principle applies to deformation: when force is applied, atoms of metals in one region can move from one place to another easily. In contrast, structures made from cement and mortar cannot easily deform without breaking because the orientation of atoms lacks a well-defined, uniform order.
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
One suspension bridge (710 m) in Kutai Kertanegara Indonesia collapse during maintenance in 2011. Human error is the primary cause of the collapse during 10 years maintenance program. Now the suspension bridge is replaced with arch bridge with the same span.
I feel like these videos are preparation for people wanting to play the Bridge Constructor games
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
yes polybridge hahaha
I'm taking notes for poly bridge, ngl
This is really useful for polybridge
PolyBridge 2
Having watched so much Aliensrock polybridge that this gets recommended to me
me
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".
@@konekoray9323 the legendary quint muscle is peak design
Same
Lol yup
Is this a poly bridge tutorial? :)
yup
for sure
for sure
for sure
for sure
Thank you for explaining in very simple terms. I appreciate the engineers who make it possible.
Bridges are hammocks. Got it
engineering is just a giant siesta
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.
Not even here can I escape from the Tacoma Bridge example.
isn't that caused by resonance, mainly?
@@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.
I think the video spoke about flexing
Told me exactly what I wanted to know.
nah use falling roads
Great video, friend! There are times when nothing better illuminates your path than a burning bridge. Enjoy your travels and good mood!
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.
I have nothing of importance to contribute to this discussion.
You're not alone
Exactly. But hey, we're here to learn. Let the teachers talk.
i am firmly inclined to agree with you based on the lack of my knowledge about this subject.
I have no witty retort, silly meme, or reference from the video to respond with.
This timestamp references nothing; 0:00 enjoy. Or dont.
The chick in the video is fine tho
This is fantastic content. I'm so happy I found this channel. Excellent animations.
Someday, i will have my own suspension bridge design that will be iconic in the world. 😁🔥
God tier ambition, massive props
Play PollyBridge. Awesome little bridge engineering game. Great videos!
i was just thinking "wouldnt it be awesome to see them play polybridge
Pollybridge is more than engineering.
It's about being resourceful and thinking using wacky solutions to solve problems.
hahaha please tell me this is a joke
@@OneDirection2V What?
Am so happy for seeing this video
These video is like preparation for people wanting to play the bridge construction
Fantastic
Thanks, Inca civilization. You have showed us the sustainable suspension bridge!
6:23 the Arthur Ravenel bridge is a cable-stayed bridge.... not a suspension bridge... the transmission of force is very different.
Half volle yoghurt He’s talking about the invention of other cable bridge after the suspension one, but thanks for pointed it out
Ok NERDS
@@riksaboi9792 That's a very weird YT channel to call anyone nerds on.
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.
I noticed that too. A cable-stayed bridge is not a suspension bridge.
now i'm gonna be a poly bridge pro, thanks
You should check the episode on chains and arch
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...)
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.
This channel is amazing, two thumbs up for u a special work❣
Thank you for explaining in very simple words.
This video makes me want to know more about geometria and maths, and THAT is a big deal
Amazing
Thanks for sharing for free. Very valuable content.
First time that i saw 25 abril bridge instead of golden gate bridge as an example 😊👍👍
this was a juicy video for me as a first year building engineer
Very nice video with better content. Thank you for uploading,...
Great simplification for architects. We need more of these videos.
Architects don't know these things.
@@Supermario0727 Architects know surprisingly little to be honest.
these videos are just simply intuitive
Thanks for making civil engineering and structural systems much more understandable as an architect
@@_blank-_
No, no. He's going to "renovate" it.
This was amazing, thank you.
I think you've given this video the description of the previous.
Thanks for spotting this oversight. I will correct it today.
@@engineeringmodels a lil' late
Amazing ❤️
I never Saw such amazing explanation
Well done! Very nice video to fall asleep to, thank you
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!!!
fantastic content, exactly what i wanted to learn
plays poly bridge once
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 .
It's a beautiful site to behold
i love that poly bridge tutorial
Nice video me and my son learned a lot thank you!
Brilliant, and fascinating, as usual. Thank you.
Excellent explanation. Thanks a lot
Thank you Sir and Mam for this educational video.
Hope the series of videos continue !
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.
I like the intuitive approach to teaching.
These engineering videos are great. No _suspension_ of disbelief is required.
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.
Thanks for the video ❤️
Cool!! A PolyBridges tutorial!!!!
This really helped me because I am supposed to make a bridge for my school project
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.
ive been wondering about this for quite a long time
Весьма познавательно, благодарю!
This was amazing! I learned so much, so quickly!
Thank you ❤❤❤
I don't know how I ended up here, but I liked it 🤷♀️
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.
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.
Step by step video solutions of civil engineering questions
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 :)
Nice video sir .
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.
Yes TH-cam, I saw the "Chain and Arcs" video because you recommended it as well, doesn't mean I'm enjoying them, so please stop.
And yes, I will watch this one as well...
Polybridge 3 looks great
The graphics are very realistic
This was an amazing lecture. Keep em coming
It was awesome. Thanks.
Sick, now I can build cool shit in poly bridge
amazing video.
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...
Really perfect for the amateur people interested in these kinds. Good work team
arent they good too because tension is carried equally in the ropes/cables?
Please do make such a video for cantilever bridges also
I appreciate you work! That's really a great content keep it up!
Thank you for making this video 👍👍👍
very good videos
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?
Best channel. Great job guys
This is so much better than physics class
Great video with great explanation!
Thank you for uploading!
There is a country where all the regions have the same language, culture, and laws.
In another country, different regions have different languages, cultures, and laws.
For the citizen of the first country, it would be easier to travel from one region to another because the person will not have to deal with new things. The same principle applies to deformation: when force is applied, atoms of metals in one region can move from one place to another easily. In contrast, structures made from cement and mortar cannot easily deform without breaking because the orientation of atoms lacks a well-defined, uniform order.
very very well done sirs! can one purchase those bridge models anywhere?
TH-cam at 4 am: Here watch this
Me after watching: fuck yeah science
is the horizontal force from the tension created from the torque from gravity?
Where can I get these materials used to build the suspension bridge? I need them for my project
do you have a video deriving the eqns / formulas used to analyse suspension bridges? 😁
Thank you for this amazing video
how are you figuring the vector angle since cables aren't straight and instead follow hyperbolic curves
3:00 that means that the sum of the Fx and Fy is reduced compared to the first position. right?
Ah yes, I love poly bridge
If you were to talk about the Tacoma Bridge I think it would fit in a video about resonance and resonant frequency better.
Great vid but don't just assume w/2 for vertical components if angles on both sides are different..
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
Brilliant!
Well, I feel inspired. Strait of Gibraltar, here I come!
Nice channel.... thanks for uploading these.
One suspension bridge (710 m) in Kutai Kertanegara Indonesia collapse during maintenance in 2011. Human error is the primary cause of the collapse during 10 years maintenance program. Now the suspension bridge is replaced with arch bridge with the same span.
Very enlightening video, thanks
When is the falling road video coming?
Keep doing this good job
What
materials do you use for the model?
This channel is great!!
Excellent video
now I know what to binge watch this weekend