Are you trying to model steel plasticity?
If so, what type of steel (ASTM grade, yield strength , tensile strength, % elongation etc.)
add a row at the begining
enter 0 for X
Enter 0 for Y
The stress vs strain input in
simulation starts at yield.
What material model and software version (and SP) are you using?
start with entering the values after the yield point of the material.
For non linear analysis, the software require the data's after the yield point.