• The shear stress must be Tau(F) or Tau - at your choice - both in definition and in Von Mises equation;
  
• Once you fix it you can see that units of Tau are wrong, it's a force while should be a stress - F/(b*L) I guess;
  
• Then you should handle the unit of F; use eq(F) to define the Von Mises yeld criterion and set the unit in the first argument of solve, like eq(F*'kN) or eq(F*'N);
  
• Finally give a range to solve, otherwise the default of the program you are running it is used;

Edited by user 25 April 2019 12:33:03(UTC)  | Reason: Not specified

Originally Posted by: AndreasH

Thank you Davide.

Sloppy mistake on my part on the shear stress definition Tau. By the way, can the solve-function return with a unit number or does it have to return a unitless answer?

I can easily fix it of course by writing F:=solve(eq(F*'kN),F,0,1000)*'kN


-Andreas-

Edited by user 25 April 2019 15:07:36(UTC)  | Reason: Not specified