Stress/strain graph of copper past its elastic limit

Watch
originaltitle
Badges: 0
Rep:
?
#1
Report Thread starter 7 years ago
#1
Image
Does the graph of D imply that the material can undergo elastic hysteresis, and therefore it is wrong because copper does not undergo elastic hysteresis? Or is B the answer because the graph of D curves a lot more than B, and therefore the strain wouldn't decrease when the stress is removed?
0
reply
joostan
Badges: 13
Rep:
?
#2
Report 7 years ago
#2
(Original post by originaltitle)
Image
Does the graph of D imply that the material can undergo elastic hysteresis, and therefore it is wrong because copper does not undergo elastic hysteresis? Or is B the answer because the graph of D curves a lot more than B, and therefore it wouldn't be able the strain wouldn't decrease when the stress is removed?
I believe that a hysteresis loop starts and ends at the origin like so:
http://www.diracdelta.co.uk/science/...s/image001.gif
0
reply
priyanshmishra
Badges: 0
Rep:
?
#3
Report 6 years ago
#3
I think answer is A because stress-strain diagram is real function diagram i.e strain is independent variable and stress is dependent variable and in real valued functions independent variable gives only unique(i.e single value) value of dependent varialvle ,as in all three i.e B,C,D strain gives multiple values for single strain
0
reply
Stonebridge
Badges: 13
Rep:
?
#4
Report 6 years ago
#4
(Original post by priyanshmishra)
I think answer is A because stress-strain diagram is real function diagram i.e strain is independent variable and stress is dependent variable and in real valued functions independent variable gives only unique(i.e single value) value of dependent varialvle ,as in all three i.e B,C,D strain gives multiple values for single strain
Here's the textbook diagram:

If you remove the stress at C the material returns to O'

Image

Which answer do you think is correct.
0
reply
jj1254
Badges: 0
Rep:
?
#5
Report 3 years ago
#5
its B. A describes the energy required to stretch the wire. C cannot be the answer as the wire will want to unstretch back the way it did, so it will take the linear straight part. with D, it won't curve back once you have passed the elastic limit (limit of proportionality) of the wire. instead you can think of it as if the wire has a new youngs modulus. youngs modulus' are found by finding the gradient of the linear line of stress over strain. therefore when the wire is unstretching, it will take a linear path not a curved one- A.
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Current uni students - are you thinking of dropping out of university?

Yes, I'm seriously considering dropping out (176)
14.53%
I'm not sure (56)
4.62%
No, I'm going to stick it out for now (354)
29.23%
I have already dropped out (35)
2.89%
I'm not a current university student (590)
48.72%

Watched Threads

View All