How many disasters and faillures from bad material choice? 4

[enginesrus]

I can think of and have seen many failures, due to engineers choosing the wrong materials to make or build the devices from.
Lets start naming some.
I'll start out with the use of flammable magnesium castings in old aircraft engines.

 

[FacEngrPE]

Many - that was one of the first stories i heard in my first materials science class - An aircraft engineer working in a shipyard, specifying high strength aircraft bolts for use on a barge. Within hours the bolts were failing and parts shooting across the barge. An example of chloride stress corrosion cracking

The recent Tapenzee bridge replacement experienced a similar problem
A Construction Company Tried To Conceal Broken Bolts On The Tappan Zee Bridge: Albany Times-Union

 

[cvg]

underground storm drain made of HDPE pipe
fuel leak from a traffic accident drains down into the pipe
bystander flips a cigarette into the catch basin, fuel ignites and burns the pipe
road collapses

 

[moon161]

Easy, challenger and titanic.

 

[TugboatEng]

I don't believe either the Titanic or Challenger accidents or directly caused by poor material choice. For Titanic the design of the ship allowed for excessive down flooding, and with Challenger the shuttle was launched outside of it s design operating window.

 

[JohnRBaker]

We had a situation once where someone decided to replace a series of steel flanged wheels/rollers with ones made of urethane to reduce noise on a conveyor system. Note that these were free-turning wheels with a self-lubricating bronze bushing. Everything worked fine for a couple of weeks, until the new wheels started to wobble and eventually fall apart. It turns out that the steel wheels were better at dissipating the heat generated from the bushing turning on the fixed shafts than the urethane wheels. They were basically 'melting', or at least the area that contacted the bushing would soften until the urethane wheel separated from the bushing.

Another problem that we had, which was sort of ongoing for a while, was when we started to replace steel frameworks of machines with aluminum. It was done for a couple of reasons, first off, we built machines used in large commercial bakeries and so all of our equipment had to safe for use in a facility which produced food. Now the parts of the machines which actually made contact with the food product, usually bread dough or loaves of baked bread/rolls, these parts were either stainless steel or plated with something like electroless nickle or some other safe material. However, the framework of the machines were often fabricated from rolled steel mill shapes, like angles and channels. Stainless was just too expensive and plating an entire frame wasn't cost effective either, so we used USDA approved paint (which meant that if some chipped off and fell into say a bread pan, it wouldn't harm anyone). But it was always a problem when these machines were operating in a production environment. So the decision was made to replace the steel rolled shapes with equivalent aluminum extruded shapes, which were readily available. Now in about 95% of the applications, this worked just fine as the steel fabricated structures were over-designed so the lower yield point of aluminum wasn't an issue. Now some of our machines were quite wide, often 12 to 16 feet, which long 'thin' cross members, and once in awhile the aluminum mill shape that replaced the same profile steel shape would deflect more than what was considered acceptable. The good news was that you could usually find a different profile that fit in the same space with a larger area modulus, and when we couldn't buy something off the shelf, we would resort to having a custom profile extruded for us, if we had enough usage to cover the fee for the custom die(s).

John R. Baker, P.E. (ret)
EX-'Product Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[IRstuff]

Challenger the shuttle was launched outside of it s design operating window.

from Wikipedia, so design failure

https://science.ksc.nasa.gov/shuttle/missions/51-l/docs/rogers-commission/Rogers_Commission_Report_Vol1.pdf[/URL]]
The commission determined that the cause of the accident was blowby occurring in a field joint on the right SRB, and found no other potential causes for the disaster.[3]: 71  It attributed the accident to a faulty design of the field joint that was unacceptably sensitive to changes in temperature, dynamic loading, and the character of its materials

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[spsalso]

Any bridge where a tension member has the merest HINT of concrete on it.

And I LOVE concrete.


spsalso

 

[FacEngrPE]

In 1992 a large number of flanges were imported that were made with incorrect materials, and unallowed fabrication techniques. The attachment contains the National Board paper.
NRC Information Notice No. 92-68: Potentially Substandard Slip-On, Welding Neck, and Blind Flanges

A number of failures resulted.

 

[Eufalconimorph]

Almost any use of Tantalum capacitors. The little bastard things just want to be on fire.

 

[thebard3]

Aluminum superstructures on warships, still used and accepting resultant problems due to stress cracking and poor fire resistance.

Brad Waybright

The more you know, the more you know you don't know.

 

[thebard3]

Flammable cladding used on high- rise buildings

Brad Waybright

The more you know, the more you know you don't know.

 

[Demented]

The use of 18-8 and 6061 fasteners to attach raw 6063 Aluminum to 304 Stainless in marine environments.

Precision guess work based on information provided by those of questionable knowledge

 

[TugboatEng]

We have aluminum wheelhouses on many of the tugboats in my fleet. One goes back to 1980. The ones attached with Detacouple have held up quite well.

 

[Reverse_Bias]

Plenty of materials can create environmental or public health disasters unrelated to whatever the material was being used to design.
Examples: Asbestos, DDT, Lead

 

[Reverse_Bias]

I've heard plenty of horror stories about Kapton wiring.

https://hackaday.com/2018/04/04/kapton-miracle-material-with-a-tragic-history/

 

[TugboatEng]

That is a great example, Reverse.

 

[CWB1]

HMMWVs had magnesium run flats inside of unbalanced steel wheels wrapped in 37” bias ply tires for the first decade or so. They also had no sound deadening and often had front suspension issues from being beaten off-road by 20-something Joe. Noticing a flat tire with run flats can be tough under perfect conditions bc tires won’t drastically change diameter with loss of pressure, so you don’t get much pull on steering. In the real world that translates to Joe not noticing flat tires over the noise and tire vibration until he’s worn through the tire to the magnesium run flat, causing a very fast-burning, very hot fire. I saw several burn in eight years and wouldn’t be surprised to learn thousands of trucks were lost bc of that design.

 

[AusG]

Substitution of dodgy materials or poor original spec? I think the flammable cladding is the worst recent example and contains elements of both.

 

[Reverse_Bias]

I remember when people in Boston finally thought the "Big Dig" nightmare was over once it opened. Then about a year later a piece of it collapsed. It turned out to be the epoxy. Caused a lot of lawsuits and additional traffic nightmares.

https://www.designnews.com/materials-assembly/epoxy-creep-main-factor-big-dig-ceiling-panel-collapse

https://en.wikipedia.org/wiki/Big_Dig_ceiling_collapse