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AS Physics - Elastic limit and yield point?

What's the difference between the elastic limit and the yield point of a material? Wikipedia seems to say they're the same thing but the Edexcel spec says we need to know what they both are and my revision guide has labelled them as different points on a stress-strain curve. Any help on this?
Reply 1
Elastic limit is when the material stops behaving elastically and begins behaving plastically - from here onwards it would no longer return to it's original length.
Yield point is when the material suddenly starts to stretch without any extra load.
schnapster
Elastic limit is when the material stops behaving elastically and begins behaving plastically - from here onwards it would no longer return to it's original length.
Yield point is when the material suddenly starts to stretch without any extra load.

yep your right, ive got a physics exam on thursday so i went over all of thisd stuff today :wink:
Reply 3
pakizrulez
yep your right, ive got a physics exam on thursday so i went over all of thisd stuff today :wink:


Yeah, same, I've been revising materials today for Thursday as well :yep:
Reply 4
You guys have a physics exam on thursday? Is it not unit 1?

And yeah,
elastic limit - maximum amount a material can be stretched by a force and still return to its original shape
yield point - the point where there is a large permanent change in length with no extra load force
Reply 5
Oh ok, I understand the difference from those definitions.

My revision guide has a slightly different definition for yield point which says that the yield point is the point after which there is a large increase in strain for a small increase in stress. If there is also no increase in load force, does this mean the cross-sectional area decreases just before the yield point for the stress to increase?

Also, can anybody show me where a yield point is on a stress-strain curve?

Thanks
Reply 6
Bump, anyone?
Reply 8


Ooh, I didn't see that thread, thank you :biggrin:
yield point :- interface between elasticity and plasticity
a) upper yield point
b) lower yield point

elastic limit - up to which material can sustain the load and return back to its original position.
altho' these two point are so close to each other it can be treated as one
it's specially for ductile material like aluminum
but in steel you can treat them as one


it's depend upon material whether it's brittle or ductile

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