Accelerated Arrogance: The FIU Pedestrian Bridge Collapse

I'm approximately a million hours away from being a structural engineer, but I think I could look at the cracks shown in the video at 6:49, 10:47, and 16:20 and say that maybe they shouldn't be going ahead with moving the bridge into place.

I never would have thought of the shifting forces during the movement of the bridge from its initial fabrication location, but the need to constantly restress the concrete with each move is fascinating. I would think that would require the concrete to be stressed and stressed and eventually over-stressed.

Fast-Tracked Failure: The Hyatt Regency Walkway Collapse

I've been watching videos from Brick Immortar of late and will have another one from the same channel next week, but I could pick probably any of these videos and post them here. They all seem to analyze famous engineering failures, quickly recap the incident, then summarize the causes of the failure.

This one is one I'd heard about and that I've seen discussed as a famous case of plans being adjusted without proper checking to see if that seemingly minor change would be problematic. This is, however, the first video on the incident that I've seen discuss that the original design would have been problematic over time as well.

What Actually Happened to the Concorde

This video didn't answer the question I was thinking it would. I was thinking it would go through the economics of why the Concorde no longer flies. Instead it went through the failure analysis following the only fatal Concorde crash, that of Air France 4590 on July 25, 2000. That does appear, however, to have been the nail in the coffin of the Concorde's commercial life.

The first five or so minutes of the video introduce the crash and the beginning analysis. At 5:00, then, the first clues emerge in the form of a sound recording of a burst tire and a remnant of irregularly-drilled metal strapping among the wreckage. At 10:00, the materials testing gets into fracture mechanics to determine how and when the fuel tank ruptured.

This might not be the best video to watch if you have a fear of flying, but it's fascinating to see how much can be discovered from how little was recovered.

The Disaster That Changed Engineering: The Hyatt Regency Collapse

The initial design was good.

The engineer signed off on the design change.

He shouldn't have.

I'm always appreciative of someone who can explain complex ideas in such a simple fashion, and Grady from Practical Engineering is such a someone, using a simple model to show the differences in forces in the original and revised design for the walkways.

Scary! Massive waves on huge road bridge send Volgograd drivers ashpalt surfing

It's not the Tacoma Narrows Bridge or anything.

Actually, it's the Volgograd Bridge in a video taken in May 2010. Seems that it has - so far at least - had a much more successful fate than did good ol' Galloping Gertie. Seems that they've installed 'semi-active tuned mass dampers' to take care of the oscillations.

That must make for far less entertaining driving across the bridge.

Sep 11 - "Why the Towers Fell" - Nova PBS

It is human nature to look back with one eye to the future. If we can just figure out why that happened, we can make sure it doesn't happen again. That is, at its core, what failure analysis is all about.

NOVA, the PBS series, produced the documentary "Why the Towers Fell" looking at the conclusions of the engineers and scientists on the government's exploration panel attempting to answer the titular question. In their findings there are a number of material science connections...

• tradoffs among cost, weight, and strength - particularly at 11:30
• design constraints - 12:45 (designed for impact of a Boeing 707, the largest at the time of design)
• mechanical testing methods (sheer, tension, vertical load) - 33:30
• heat softening of the steel - 37:45, 44:35 (and throughout in small mentions typically as "the heat would have softened the steel")
• failure analysis - all throughout, particularly at 45:00

NOVA also posted a website of information related to this episode, much of which is still online. Some links are starting to fail, however. The best of these are a very readable summary of the findings, the engineering history of the Towers, and a java interactive showing what metal atoms do as heat is applied.

This one's tough for me to post and was even tough for me to watch. I didn't have a direct connection to the tragedy of the Twin Towers, but I had at least one student who did, who knew someone on one of the planes. If it isn't already obvious, be aware that some of our students - or coworkers - may have closer connections and may still struggle with memories of the incident, of loved ones who were closer to the Towers, or even - like me - have memories of being in the Towers and being two or three relationship steps away from the tragedy.

Jet engine testing (superalloys)

I know a couple of our master teachers who should NOT watch this video because of their little fear of flying thing.

I, on the other hand, have no fear of flying at all. I don't fly very often - about twice in a typical year - and am totally relaxed when I am flying because I know that airplanes are overengineered to the point of ridiculous safety. I hope...

This video shows Rolls Royce testing one of their jet engines in the case of engine turbine blade during an event of catastrophic failure. The super slow-mo footage of the turbine going off balance and recovering is actually terrifically reassuring to me as a passenger.

Why Things Fail: from tires to helicopter blades, everything breaks

I'm really digging on Wired magazine's materials science coverage of late. I don't know if they're intentionally adding more reportage of materials or if it's a coincidence. I'm happy either way.

This month's issue has an article on Ford's Building 4 testing complex in which they test automotive parts - gas pedal hinges, engines, even entire vehicles - to failure and try to develop a failure analysis curve to show how long they can expect to have a part survive under typical circumstances. The article also covers Vextec - a failure analysis company - and their efforts to computerize the failure testing process, developing a way to model materials on the computer, create thousands of virtual versions of the material, and test each of them to failure without making and destroying thousands of prototypes, something that aligns wonderfully with the Materials Genome Initiative.

Good stuff here, plus it's about cars...always cool.

Point Pleasant Silver Bridge Part 2

Today is the 72nd anniversary of the failure of the Tacoma Narrows Bridge - a more famous bridge collapse here in the US than the one shown in the video here. I'll post that video in a bit, but this one caught my eye for MatSciWit because of the discussion of the failure detection methods used here to find out why the Point Pleasant Silver Bridge over the Ohio River collapsed in 1967. They video uses computer recreation and eye-witness testimony to explore the pitting corrosion, tension/compression in manufacturing, and material failure on the suspension bridge.

This is merely the middle of three parts to the video. Check out the other two after the jump...