i has a question. its about springs and rubberbands.

[im a model]

which wears a metal spring out the fastest: keeping it compressed or repeatedly compressing it and letting it extend?

also, which wears out a rubberband the fastest: keeping it stretched out or repeatedly stretching it and unstretching it?

do most materials act this way?

any evidence is much appreciated.

[Borodog]

Paging BCPVP . . .

Repeatedly compressing and extending a spring will wear it out; keeping it compressed has prety much no effect at all.

I don't know about rubber bands.

[m_the0ry]

[ QUOTE ]
which wears a metal spring out the fastest: keeping it compressed or repeatedly compressing it and letting it extend?

also, which wears out a rubberband the fastest: keeping it stretched out or repeatedly stretching it and unstretching it?

do most materials act this way?

any evidence is much appreciated.

[/ QUOTE ]

Wearing out is too vague of a term. Repeatedly stretching and compressing a metal spring will eventually lead to metal fatigue which is a form of wearing out. Keeping the spring compressed will not damage the spring so much as alter its behavior by changing the spring constant.

As for rubber bands I am not sure how the molecules in rubber are organized but I believe since it is an elastic organic compound it would not fatigue like metal. It will break if stretched beyond a certain point but any point prior to that and the rubber band will reassume its natural state and be indistinguishable from one that wasn't stretched.

[im a model]

about the rubberband, say i wanted to stretch out the elastic on the waist of my sweatpants, would i be better off holding it stretched out or unstretching and stretching it a bunch of times?

[Wakko]

[ QUOTE ]
about the rubberband, say i wanted to stretch out the elastic on the waist of my sweatpants, would i be better off holding it stretched out or unstretching and stretching it a bunch of times?

[/ QUOTE ]

why would a model ever need to do this /images/graemlins/confused.gif

[txag007]

[ QUOTE ]
[ QUOTE ]
about the rubberband, say i wanted to stretch out the elastic on the waist of my sweatpants, would i be better off holding it stretched out or unstretching and stretching it a bunch of times?

[/ QUOTE ]

why would a model ever need to do this /images/graemlins/confused.gif

[/ QUOTE ]
Maybe it has to do with yo-yo dieting. /images/graemlins/smirk.gif

[RoundGuy]

[ QUOTE ]
[ QUOTE ]
about the rubberband, say i wanted to stretch out the elastic on the waist of my sweatpants, would i be better off holding it stretched out or unstretching and stretching it a bunch of times?

[/ QUOTE ]
why would a model ever need to do this /images/graemlins/confused.gif

[/ QUOTE ]
So the pants fall low enough to show 1/2 her ass, rather than staying tight around her waist. Duh! You guys need to spend more time in OOT.

[guysmilie]

Natural rubber degrades over time and will become brittle. As it would be under considerably more stress if streched the whole time I believe it would fail (break) sooner if kept under constant tension. However that probably won't work for your sweat pants. LOL. This is one of the weirdest threads I have seen. Can you tell us what led you to post this question.

I think your best bet is to buy some new sweats.

Guy.

[Victor]

i vaguely remember learning about springs in college.

i think it depends on how much you compress it. fully compressing it will wear it out the fastest. most springs are designed so they only compress the optimal amount for long life.

also, i think there are ways to specifically design a spring for that is constantly loaded vs compressing and returning.