Structural Shapes Ranked and Reviewed - Which one Wins?

There are many structural shapes and for the most part, they all have at least one feature that is more advantages compared to the other shapes. Deciding on which one is the best structural shape is not straight forward (and probably not possible) since being able to resist high loads is only the beginning of the analysis. In this video, we (attempt to) analyze and rank the most common structural shapes. Our analysis takes a fixed area to compare various shapes in terms of bending, buckling, torsion, symmetry, and workability.

00:00 - Intro
00:58 - Analysis Criteria
04:01 - I-Beam (Wide Flange)
05:34 - Rectangular
07:47 - Circular
09:57 - Channel
11:17 - Tee
12:04 - Angle
12:59 - Analysis Results and Discussion
14:13 - Sponsorship!

This video was sponsored by Brilliant!

[katsu-graphics]

I'm retired mechanical designer. . .We used STAAD structural analysis software in the 1980's . . . Cell Phone towers have wind load and ice build-up weight, so hollow was good.. . . .acid plants have corrosion problems with hollow members, so hollow was bad. . . .channels and angle iron have totally different applications. . .and Equipment supports made of tubular members need extra flanges welded on to attach Electric / Hydraulic lines, so I-Beams are perfect for 1 and 2 story equipment platforms. . . .Every situation is unique.

[athompso]

Love the use of radar plots, this is an ideal situation for using them.
I also can't believe it never occurred to me that the framing+sheathing in home construction created a compound I/T shape for strain calculation purposes!!!

[johnsolod]

I'm an immortal highlander who has been blacksmithing since medieval times & doing structural engineering with steel for 135 years, and I learned more from this video than during my entire cursed existence.

[ronnyhaldorsen]

I think it is a bit strange to rate H- beams higher than square hollow profiles when it comes to workability. For welded constructions the fabrication cost for H-beam based structures are typically 3-4 times compared to square hollow profiles. Due to more complex prefab (cutting and weld prep), more complex welding and NDT and more time consuming surface treatment. Another huge benefit with square hollow profiles is that the other geometry is constant. If you increase wall thickness it builds inwards. Meaning in 3D models there are no changes to overall dimensions and joints if one changes wall thickness. With H-beams everything changes. I would chose square hollow profiles whenever possible.

[David-hmic]

Hurricane Katrina gave a great opportunity for the observation of structural steel failures. There were hundreds of tall billboards in and around New Orleans. Unfortunately, I cannot give the weight per foot of the supports but I can say that the external dimensions were similar. Some billboards were mounted on three or four I-beams of constant dimension. Others were mounted similarly on round pipe of diminishing cross sections as the height increased. Peak winds were in excess of 150 mph (240 kph).

My observation was that I did not see a single billboard on I-beams that was still standing after the hurricane. All of the I-beams failed by bending, not buckling, over a radius of several feet parallel to the webs of the I-beams. The bends were remarkably gentle, on the order of a 3'-5' radius. Once the I-beams gave way, the billboards themselves were pushed to or nearly to the ground. I did not see any billboards that were on pipe fail. The hollow round shape stood up to the wind very well.

[jimf]

Developing an intuitive sense of the effect of displacement of material from the neutral axis is a valuable design skill that can be only partially replaced by CAD and simulation software but a team's design effectiveness is significantly enhanced if both the software tools and the intuition are effectively utilised within the team.

[hafeeznoormohamed]

Wow, a 15-minute video that actually kept my attention!

[JustinShaedo]

A follow up with real scenarios and what (+ why) a certain option was best would be great!

[ChrisCraigie-oiun]

Great presentation! Thanks for taking the time to explain it.

[titodd]

Nice video! I liked the side-by-side rankings of the different shapes. Another great video would be if you delved more into the bracing, connection, or other practices that improve on the relative weaknesses on each type of section.

[liesdamnlies]

Came thinking I’d get a meme list, stayed for a bunch of engineering jargon and math I don’t understand.

9/10 stars, good video.

[hafdone]

Neat rating scheme and animations! Keep up the great videos

[symonortega]

Another good thing the hollow sections have is that you can make composite columns with them. Helps in the workability when you pour the concrete in. Also, it has more resistance than a normal hollow section due to the interaction of the hollow section and the concrete column, meaning it can result in having even longer span of elements than with a steel section alone.

[KenColton]

I’m a software engineer who makes web apps. Why the hell am I binge watching these videos?

[mrgreen]

Thank you for this great informational video. Keep up the good work. 👍

[ChanceNewcome]

I wish I had this in school. Quick and efficient concepts make long calculations way easier.

[bobfk]

This is very interesting !
One of my favorite courses was "Strength of Materials".
We got into some of this but not with the depth that you included.

[georgegr]

Excellent presentation. That plots are really helpful and easy to understand the differences between steel sections.

[thomasglessner]

You help us do it right the first time. Thank you.

[metalmartin]

I've worked with U Channel beams, and for their weight, they got quite good bending strength. Certeinly, a good option for longe free span structures without much torsion loads... Anyway. Nice video man.