compression force acts on both upper & lower cords of the truss that is in the rafter & lower cord # therefore we cantilevers are necessary to decrease the compression in both upper & lower cords #🇵🇰

I think I would've flourished in a class like this. But I grew up poor, therefore deserve nothing good I guess.

Thank you for sharing this knowledge. As an owner of a company expanding into modular, these insights are very valuable. Cheers

I feel sorry for are future bridge's, what ever project's 🤦🏻‍♂️🤦🏻‍♂️ i just got a diploma and LA city welding certs, journeymen ironworker 🤦🏻‍♂️🤦🏻‍♂️😅😅

Just started understanding why my favorite Skateboards are concaved!! Thank you! Lol

Masterclass in how to lose a toe

great video, super clear, thank you!

hey pointdexter

"I'm Paul's second daughter" And I express myself as an engineer 😂❤

You said others professors are wrong because pasta competitions only show one is good at building with pasta. Materials and requirements will change in the next 70 years. People are supposed to be able to work with multiple materials and adapt their knowledge to various environments and challenges. Will Harvard diplomas be cancelled if we stopped using wood and aluminum, cause if you use wood in a project you can only be good at building with wood?

They should wear safety steel toe shoes

There's a Stephen Fry book up on the shelf.. Nice! 😀

Torque?

5:05 lol I thought that one was a 2 by 4 this whole time

Steeltoes wouldn't hurt

the floppy cables thing reminds me of restringing and tuning a guitar. It's easier to do on better guitars.

Until it broke, I thought that second one was just a 2 by 4.

I enjoyed this video! It reminded me of my own college experience at the Purdue University School of Engineering and Technology at Indianapolis. I was in a double degree program that awarded an Associate of Science in Civil Engineering Technology and a Bachelor of Science in Construction Technology. We took structural design classes in that program, part of which we took two classes at the same time, Strength of Materials and Materials testing. The second class acted as a lab for the first. As a semester project we were given four small pieces of lumber and were told to use them to make a beam we would test, then right a report on the test. It was expected the beams would fail when the load would push the beam past the maximum to bending moment it could handle. My group had the only beam that didn't fail due to bending, but it failed due to shear. Our beam was the only I-beam shape in the competition. One group made a beam that was larger in depth than all the rest, making it two pieces of lumber thick and tall. The other two groups made box beams. In theory, the I beam should have supported the most load before failing. The beam with the large depth supported the most load before failure, but it was pointed out that the depth would have been limited in actual practice. We were not permitted to cut the pieces of lumber, so the I-beam had on extra thick flange. Had we been able to cut that extra piece, we could have used it as stiffeners to help with that shear. That was a fun project and the most fun class I took in college.

I don't know what I love more... how excited the students get or how excited the teacher gets. This is how education should be done!!

Some students spread the weight over a wide area and some almost stack each weight upon another. Doesn’t that have an effect in terms of breaking? Thinking in terms of ice breaking when walking vs lying down on a latter ish’’’??? And pure luck that rotating force did not cost a broken toebone or two in the classroom. Should have some kind of steelnose attached to their shoes

Perhaps you know the bridge of SNP in Bratislava from building begun in 1967 - and completed in 1972 - can it still inspire ?

Why didn’t they have bigger basis.?

If the coloumn buckles at center then why do we provide steel lapping at center of coloumn

Lol Mark Zuckerbergs father

Bro, shut up

Lots of effort, then to SEE it work to failure. That IS the learning experience.

I wonder why didn’t they use disc-shaped weights only?? A lot of the failures happen because dumbbells are top heavy and fall on the side….not because structural failure

Great video, but I had a difficult time watching the weights fall on to the brick pavers, should have put a rubber mat down.

Catastrophic failure is part of iterative design. What would have been really interesting is what 2.0 and 3.0 would have looked like if all the projects were isolated from each other. AKA inter-school competition...

I participated in the Alumni competition at the University of Houston model span contest. These were small balsa wood packages that you could only use what was in the package. Walter, very innovative transmission tower designer caused them to have to rewrite the rules. The new rule was: You can only use glue on the joints. Walter had sliced the wood into fine sheets and glued it back together. He created plywood with no weak ends and the dried glue was stronger than wood. Other things he did to walk away with the win: They could not prevent his best of all. He baked the model in the oven on low heat to dry the wood/glue. Everyone found out that kiln dried wood is much stronger than air dried wood. He sanded the shape to eliminate any excess weight. You have to consider shear in your wood design.

I liked the second design, it is the most functional and the simplest. 😮

Paul I'm a huge fan from Brazil. I teach structures for Architectural students and learn a lot from you.

Twister proof

This was pretty cool to watch. The elephant in the room as I see it though, is how the loads were applied to the models. Stacking the weights above the load carrying surface raises the center of gravity of the load and causes destabilization and rotational forces on the structures. Most failed because they were not stiff enough to handle the twisting forces, not because the structures broke. Loading below the working surface is stabilizing and reduces the rotational issues and focuses on the structures ability to carry the compressive and tensile loads. The last structure with the buckets significantly loaded gave it a major advantage over its competitors. To have a fair test, you should have all structures loaded with loads hanging from the same test rig that takes the loading mechanism out of the equation, and lets you evaluate the structures ability to carry a load. There was too much variability in the loading, as to how high the CG was, and how wide the load was spread across the working surface. I think the experiment did more to show how loading a structure effects it than the merits of the structures themselves. An extremely high CG can make a great structure look bad, while a large negative CG can make a poor structure look better than it is. I would love to see this done with the same structure loaded with the loads at varying CG's to show the effect of CG heights, and also the experiment done with a test rig that allowed the structures to be loaded at their designed load points, with a hanging load rig, so the structures can show how well they preform. Overall, this was a excellent experiment, even if the lessons learned may not have been the ones intended. I am sure that all involved had a great time.

Very cool

Should build a bridge that could withstand a ship accidentally crashing into it…

I can do better with 5 boxes of honeycomb cereal

Im to broke for college

Don’t worry, that thumbnail doesn’t make you look like a #doucheFace #lemmingMoron 😂

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.

Should all have to use popsicle sticks or Something. Obviously the 2x4 can carry alot of weight. The problem is who build a big bridge out of one solid piece

You really should have let the first student make the weight spread out like all the others, it is underrated

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!

Spaghetti has same flex coefficient as steel when scaled down to proportion

Kasabian? This universe needs to stop making me wanna read Helter Skelter

Excellent! Super fun learning. The only thing i would like to highlight in such activities is “Safety”. I see unfortunately no consideration to safety precautions in this exercise. Hope it will be addressed in future videos. Thanks

Heyy....do you have a video on how to make structural models of truss bridges?

Ya'll need steel toe shoes haha

nice

Wonder what the requirements were for this project? (What types of materials, how much materials, what types and size fasteners etc.)