How to calculate Young Modulus by Stress-Strain curve?
I have recently faced a problem related to calculating Young's Modulus.
According to the Hook law it is slope of Stress-Strain curve in the elastic area. But surprisingly I can't find even 1 case in which this Modulus is calculated rightly. for example:
1- Attached Paper: salehghaffari2011
As you see, the Young Modulus gives around 16 MPa by pic below:
But he claimed that is 210 MPa. (of course for steel it is about this value )
Where I make a mistake?