Piecewise linear mechanical property values describing nonlinear elastic stress-strain behavior

Hi. 

I am Naveen Soni,.

I want to perform piecewise linear mechanical property values that describe nonlinear elastic stress-strain behavior.

I tried the calibration of Elastic Isotropic material behaviour but results is zero. I am attaching Experimental Stress -Strain data 

  

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STRAINSTRESS
00
0.02510.0008
0.04730.0021
0.07550.005
0.10090.0102
0.12660.0197
0.15260.0374
0.17890.0706
0.18830.0882
0.20510.1309