Calling all OppoNauts! EDIT: Finished!

"Not a Sunburst Miata" (moezsayani) 10/10/2013 at 23:11 • Filed to: None

1

41

I need some help with an engineering assignment. I'm supposed to find three examples of engineering products that fulfill their design by breaking or deforming plastically. The example he used in class was a staple, because for it to be used, it has to bend out of its normal shape. What else have we got? I thought the canards on the front of the 458 deform at high speeds to increase downforce, but they go back to their normal shape so its elastic deformation instead of plastic.

EDIT: Thanks guys! I've got my 3 things. The winners were glow sticks, pop rivets, and crumple zones in cars. Enjoy this picture as my thanks.

nobody > Not a Sunburst Miata 10/10/2013 at 23:13

4

Fuses

55Buick, Oversteer Scientist > Not a Sunburst Miata 10/10/2013 at 23:14

0

Maybe a ballpoint pen? The spring has to be compressed in order to write.

andthelike > Not a Sunburst Miata 10/10/2013 at 23:14

2

paperclips?
the inside of glowsticks?
yeah i got nothing.

Velocity- Peuguette Connoisseur > Not a Sunburst Miata 10/10/2013 at 23:14

1

Airbags? I know they are only just folded up before use, but its the only thing I could think of.

DasWauto > Not a Sunburst Miata 10/10/2013 at 23:15

0

Bumpers, racecar nose cones, basically anything designed to absorb energy.

Alternatively, in the same vein as staples, pop rivets.

blackchair > Not a Sunburst Miata 10/10/2013 at 23:15

1

Packing material like peanuts, bubble wrap, and styrofoam.

ddavidn > Not a Sunburst Miata 10/10/2013 at 23:16

0

I'm not a real edumacated boy, but do suspension springs work this way? My thought is that they would be elastic to a point but also plastic? I don't really know.

Kugelblitz > Not a Sunburst Miata 10/10/2013 at 23:16

1

Pop rivets? Fly rods? Springs?

Party-vi > Not a Sunburst Miata 10/10/2013 at 23:17

0

Rivets would be a good example.

Not a Sunburst Miata > andthelike 10/10/2013 at 23:17

0

I thought of the glowsticks right after i posted this. I'm adding it!!

Satish Kondapavulur > Not a Sunburst Miata 10/10/2013 at 23:18

0

Drug capsule tablets.

Not a Sunburst Miata > 55Buick, Oversteer Scientist 10/10/2013 at 23:18

2

But after you use it it goes back to its normal shape. I'm looking for things that stay permanently deformed after use.

scoob > Not a Sunburst Miata 10/10/2013 at 23:19

0

As DasWauto said, definitely bumpers. Maybe guard rails?

blackchair > blackchair 10/10/2013 at 23:19

1

Maybe even brushes or bristles. Velcro or the 3M command hooks. It has to be deformed for it to prove it can be removed without damaging the surface.

pdthedeuce > Not a Sunburst Miata 10/10/2013 at 23:19

1

the stop saw breaks itself to save your fingers .

http://www.sawstop.com/how-it-works/

DasWauto > 55Buick, Oversteer Scientist 10/10/2013 at 23:20

0

When something deforms but can return to its original form, that is elastic deformation. Plastic deformation is the opposite, it doesn't and isn't able to return to its original form.

Ramblin Rover - The Vivisector of Solihull > 55Buick, Oversteer Scientist 10/10/2013 at 23:21

0

Compressed spring = elastic deformation, not plastic.

dogisbadob > Not a Sunburst Miata 10/10/2013 at 23:22

0

clay/pottery?

Tamper-proof security labels? They work by being difficult/impossible to remove intact once applied.

nobody > Not a Sunburst Miata 10/10/2013 at 23:24

1

All of these parts

DasWauto > nobody 10/10/2013 at 23:26

0

Is that really deformation though? Yes, it deforms but that's not the mechanism; it melts.

Party-vi > Kugelblitz 10/10/2013 at 23:27

0

Not springs - those are elastic.

GhostZ > Not a Sunburst Miata 10/10/2013 at 23:27

0

Snap-to-light Flares (although glowsticks are similiar), and crumple zones to prevent a wreck in a car.

MtrRider Just Wants Doritos > Not a Sunburst Miata 10/10/2013 at 23:27

0

A vehicles crash structure is designed to do just that. If you never use a staple, it will not bend. Once you use it, it is no good. Just like a crashed car.

Ramblin Rover - The Vivisector of Solihull > Not a Sunburst Miata 10/10/2013 at 23:28

1

Try pop rivets. They're a twofer, they expand by deforming plastically, then an internal element breaks.

Also cite-able, any type of freshness seal or packaging seal like the ring on a milk jug or soda bottle.

Further, common wood is installed by breaking and plastically deforming the fibers within.

Finally, if you want to be an ass, you can say tensile test material samples. A product that fulfills its design (either proofing a material or calibrating a machine setup) by failing at a given loading.

nobody > DasWauto 10/10/2013 at 23:30

0

Ummmm, maybe? I don't know enough much about fuses, just that they serve their purpose by failing.

The Opponaut formerly known as MattP123 > Not a Sunburst Miata 10/10/2013 at 23:32

1

Cheese.

DasWauto > nobody 10/10/2013 at 23:32

0

Fair point.

Agrajag > Not a Sunburst Miata 10/10/2013 at 23:32

0

Airbag, explosive bolts, a bullet? Not sure if they would count.

55Buick, Oversteer Scientist > Not a Sunburst Miata 10/10/2013 at 23:32

0

I understand now. How about a "safety seal" on medicine bottles?

DasWauto > Not a Sunburst Miata 10/10/2013 at 23:35

0

Firing cap on a bullet.

Frank Grimes > Not a Sunburst Miata 10/10/2013 at 23:35

0

body armor?

Scott Keelan > Party-vi 10/10/2013 at 23:35

1

Rivets came to my mind as well. You could also add crush washers to the list. Maybe filler metals used for welding or soldering?

Party-vi > Scott Keelan 10/10/2013 at 23:36

0

Epoxy as well.

dogisbadob > DasWauto 10/10/2013 at 23:42

1

Well it's deformation due to electrical/thermal stress, right?

Casper > Not a Sunburst Miata 10/10/2013 at 23:45

1

There are a lot of things that use plastic/aluminum bolts to shear away safely. You could also look at crush washers/seals and the like that deform to either seal something or to lock a nut/bolt in place.

There are literally thousands of examples all around you. It's tricky because you generally don't even think about what they do in that way. Even engines have gaskets that permanently deform when crushed into place.

Not a Sunburst Miata > DasWauto 10/10/2013 at 23:46

0

I don't think this would work since fuses work until they break or melt. I'm looking for something that breaks or plastically deforms and that fulfills the design purpose. Like glowsticks.

dogisbadob > Not a Sunburst Miata 10/10/2013 at 23:55

0

No, fuses are designed to blow when there is too much current flowing through. They are a safety device to prevent shit like a fire from a short circuit.

Like an electrical crumple zone

Kugelblitz > Party-vi 10/11/2013 at 09:15

0

Smelling salts! You have to break these little chambers to release ammonia. What about pill capsules? Don't they have to dissolve to release meds? Explosive bolts? Sabots on penetrators fired by tanks? Squash head explosives? Explosively formed projectiles? What about WW2 squeeze guns that used a frangible soft iron sabot in a barrel that narrowed in diameter, like a 28mm/20mm anti tank gun. Would a re-entry heat shield work?
My brain is working better today.

Party-vi > Kugelblitz 10/11/2013 at 09:19

0

O_O damn!

Well I suppose all those work except the heat shield as not all of them deform (although I'm sure the case could be made for it).

Kugelblitz > Party-vi 10/11/2013 at 09:28

0

Pull tabs on beverages. Ok I have to stop. This is fun, thanks.

Party-vi > Kugelblitz 10/11/2013 at 09:38

0

Hey that's actually a good one!