test.sm (7 KiB) downloaded 29 time(s).


Dear all. I am trying to solve an equation, eq. See attached .sm file. The equation does not have the variable directly, but via other definitions. I can't make this work. Anyone out there able to help quickly?


-Andreas-

Hello Andreas,

there are several issues in your worksheet.

• 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;

test - r1.sm (11 KiB) downloaded 38 time(s).

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-

Wrote

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-

Yes I forget it, that's the way to set the output units (solve as for now can't handle automatically input/output units of unknowns).