What is the difference between these two and why one is work and the other one is not

[yoohooos]

r = -1 epsilon y = 60ksi/29000ksi

File is attached below, in the final page.

Thank you very much!

[ValeryOchkov]

[LucMeekes · Accepted solution]

In your first case epsilon-s is less than epsilon-y, your last else-if catches that. In the second case epsilon-s and epsilon-y are equal, none of your if-cases catches that. You have one situation not accounted for. Prime rightfully complains about that.

Success!
Luc

[yoohooos]

Thank you!