The Stanford Duck Syndrome and Stress Strain

Posted by at 2:29AM

Apparently, this year’s crop of frosh are super stressed out.  That, it seems, holds for much of Stanford – it’s Week 5 and the bikes at Green already are filling the designated parking.  (That’s not typical, I think).

Civil engineers worry a lot about stress (the pounds per square inch type).  The classic graph of civil engineering, in fact, is the stress-strain curve.  When you put a piece of metal under tension, it gets longer.  We call that change “strain.”  As you increase the stress (the amount of force per area) on a piece of metal, it will strain more and more – linearly with the amount of stress.  That is, if you double the stress, it will stretch twice as much.  The fancy name for that is “linear elastic” behavior.  At some point, the metal breaks down and will start stretching even as you apply the same amount of stress.  We call that the yield point – it can be seen on the graph below as the point where the curve goes horizontal.  If you strain the metal still further, it will become tougher and resist more stress (for a bit).  That’s called strain hardening.  Past that point, well, it breaks.

The Duck Syndrome is Stanford’s take on stress – be stressed out, but don’t show it!  It’s popped up recently in the campus literary magazine, which ran a front cover knock-off of Edward Muybridge’s horse study…as ducks. Anyways, the stress-strain curve is a nice way of thinking about the duck syndrome.  You apply a lot of stress, but people don’t yield.  They’ve got a very steep stress-strain curve (to get technical, a very high Young’s Modulus).    They probably have a yield point and probably some sort of strain hardening (the “ah, screw it I’mma stay up and get this done” moment).  And, much like the steel in bridges, well, we hope they don’t go much beyond that point.

In black, a classic stress-strain curve for steel. Notable is the linear-elastic region (the straight bit), the yield point (where it goes flat), strain hardening (where it gets stronger as it yields) and, well, fracture (the end of the line). Same thing for the Duck Syndrome, weirdly enough...

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One Response to “The Stanford Duck Syndrome and Stress Strain”

  1. Carol Langlois says:

    Who coined the term “duck syndrome” at Stanford? I’d like to contact them about some research and give them proper credit for the term.

    thank you
    Dr Carol Langlois

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