Maximum plastic strain for low carbon steel ?

[LCform]

Hi All

I have a low carbon steel wire , 1033 , which when I applied a tension test on it , and from the force displacement curve I got the true stress-strain curve , but I wonder why the maximum strain that I have got is 0.14 , in which as in the test , the wire breaks, but in standards and some other resources , I see this material has a maximum true strain of 2 , to calculate the true stress - true strain I have used all the instructions that is in every related source :

true stress = eng stress*(1+strain)

True strain=ln(1+eng strain)

 

[desertfox]

Hi
Try this link

http://academic.uprm.edu/pcaceres/Courses/MatEng3045/EME8-2.pdf

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[TheTick]

just one sample?

 

[LCform]

Thank you

That link has exactly what I did ! no I did 3 samples, 3 diameters, but in all of them I have calculated the max true strain low, not close to 2 , would you tell me, what could be the reason ?

 

[desertfox]

Hi

I think on page three of the link it shows a graph of true strain and engineering strain, so assuming I am not misunderstanding what I read the true strain appears to be an ideal theoretical case but because of work hardening within the material and other flaws or inclusions the strains don't quite match.

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[desertfox]

Hi his might help better

http://www.srmuniv.ac.in/openware_d_loads/u10lect 2.ppt

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[LCform]

Thank you all

the problem was from my side , i am sorry , I had written LOG instead of ln in excell