sadbutrue
kewl member
I DOUBT; THEREFORE I AM!!!
Posts: 115
|
Post by sadbutrue on Oct 12, 2005 14:01:44 GMT 7
hi!
This problem is from my friend in his design [dili ni sya msuans], but i dunno wat 2do, daz why i post it here.
Given are two tables for a specimen of medium-carbon steel with initial diameter 0.503 in and gauge length 2 in. The two tables are labeled "Elastic State" and "Plastic State".
The first table gives the Load vs. Elongation...Load ranging from 1,000 lbf to 9,200 lbf and Elongation ranging from 0.0004 in to 0.0089 in.
The second table gives load vs. Area. Load ranging from 8,800 lbf to 14,800 lbf and Area ranging from 0.1984 in^2 to 0.1077 in^2.
The question is to plot the engineering stress-strain diagram using two scales for the unit strain (epsilon), one from zero to about 0.02 in/in and the other from zero to maximum strain.
I don't understand what it means by the bold part. Also, how can I plot stress vs strain for the plastic part if I only have the change in area...I don't have the elongation so I can't find strain.
Any help would be appreciated.
tnx
urz,
sad
|
|
sadbutrue
kewl member
I DOUBT; THEREFORE I AM!!!
Posts: 115
|
Post by sadbutrue on Oct 14, 2005 11:51:41 GMT 7
Ah ok guyz, i have some idea but i didnt yet got the correct answer :'(but some sort of idea leadin to BINgo! Kasi ganito pala yun. In the purely elastic region, the strain is given by å= ó/E, and this begins before the 0.2% (strain) offset, where Yield strength is usually determined. The point where the stress-strain relationship departs the purely linear relationship is the proportional limit.
If one loads a tensile specimen to the point where stress = yield strength (as determine from the 0.2% offset, then there should be approximately 0.2% permanent (plastic) deformation (elongation) remaining when the specimen is unloaded (in a uniaxial test).
Going beyond yield, up to the ultimate tensile strength, the relationship between stress and strain is more complicated. At ultimate tensile strength, the uniform elongation is reached and that is when necking begins. Or course, this assumes a more or less ideal material. __________________ Getting the 'right' answer is important, but understanding how to solve the problem (i.e. how you get the right answer) is just as important, if not more so.
pasensya sa abala hope you can stil contribute bout this. salamat jud kay naay online inquiry diri.
- SAD
|
|
|
Post by DJ ADZ™ on Jul 13, 2007 10:08:15 GMT 7
kaw lang man ang nakasabot ani manong. ^_^
|
|