ACCEPTED SOLUTION
Accepted Solutions
Awesome, thank you.
I trying to use solve block and getting some errors ,
I use prime 10.0, I have uploaded my sheet, open to suggestions to do it another way
You should attach the Prime worksheet (the .mcdx file), not just a picture.
Apart from that, your equations are relatively simple, so you can have Prime find the equalities like this.
Following that, you can evaluate the two Pi functions with their arguments filled in, to have the results calculated numerically.
Success!
Luc
You stated 4 days ago that you'd uploaded a worksheet. I don't see it. Did that fail as well?
Normally when editing a posting you should be able to attach a worksheet either by drag/dropping, or by browsing (see red arrows below:
This forum usually accepts Prime worksheet without the need to zip them.There should be no problem with any worksheets (.mcdx files) saved by any version of Prime.
What's the error message you get?
Luc
It's good that you tried this:
But something went wrong, due to this incredibly nice feature of Prime: Autolabelling.
Prime automatically tries to label each identifier the right label: Variable, Unit, Constant etc.
It is handy, but too often it goes wrong, and you should be aware of that.
Notice the two e's in the expression. The one on the parameter list to the function looks different from the one between Pi and yt.This means they are different items. The first is a variable, the second (bold green) is a constant, namely the Euler number, base of the natural logarithm.
You should change its labelling to a variable and see what happens.
Success!
Luc
You really should finally succeed in uploading your worksheet!
It seems that you forgot to define a guess value for P.i.
But with the values you provide, the expression in your solve block (its linear in P.i !!) never reaches the value of sigma - at least not for positive values of P.i.
If negative values are allowed, any value below -348,67 kN is a possible solution.
This does not change significantly if you correct your error in the definition of M.g (N and not kN).
Hi,
It is mismatching units. The calculation of MT is in kN/m being the load on the beam but must be the moment on the beam that is w* L^2/8 in kN*m
Cheers
Terry
You used the wrong sigma in your inequation.
According to the screenshot in your sheet it should be sigma.t, not sigma.c.
The resulting value still is not the same as in the picture, but closer 😉
I also spotted some discrepancies in the picture.
,) The author uses P.e in one inequation but is talking about P.i to the right of it
.) at the top we read sigma.t=2.02 MPa, but in the picture the author writes in violet that is should be negative and a different value, -1.58 MPa.
BTW, we get the result from the picture if we replace sigma.t by -sigma.t !
A solve block with find is not made for solving inequalities and Prime will return the first value it finds which fulfills the constraint(s) starting with the guess value. As every value larger then (approx.) 1312 kN is a solution its important to chose a guess value which is lower as otherwise Prime would return the guess value unchanged:
Therefore, I think it is better to use an equation and not an inequality.
Its up to you anyway to decide if the result means P.e > 1312 kN or if it means P.e<1312 kN ;-).
The plot confirms the results and can also help with the decision < or >.
Prime 10 sheet attached
I have no experience in your field of work.
In your last sheet it was necessary to replace sigma.t by -sigma.t to get the results from the pic.
Maybe this helps here again?
This results in
Not sure which value you expected here ...
According to your calculation formulas P.i always is about 5,26 % larger than P.e (P.e is exactly 95 % of P.i)
