Hello! I'm trying to replicate the

[Sajjad2164]

Hello!
I'm trying to replicate the Elastic-Plastic Analysis – Local Strain Limit of PTB series. I'd like to plot the following contour. I made a contour with the expression for limiting triaxial strain, but it's not the same as the contour in PTB. Can anyone tell me how to plot the same contour as PTB?

 

[TGS4]

That's simply a plot of Equation 5.6. Depending on your software, you would create a variable that perform that calculation.

I'm sort of confused by your question.