I want to solve a mechanical torsors problem, but I don't know how to go about it with Mathcad
I have a circular platform. on this platforme i have 3 point B1,B2,B3
on each point i have a forces, respectively F1,F2,F3. About it i know directional vector for each forces.
My platform have a spherical joint in this center (point C).
And i have a torsor which define exterior mechanical load applied on platform at C point.
1°/ i write mechanical component:
obviously expressed respectively at each point
Now, i want to solve it find FB1,FB2,FB3,X,Y,Z
For this, i want to make a torsors transportation on C point!
And now! i am stuck😥
I make a light mc file for add to this post
And after all torsors transportation, i want to solve the system like this example:
/ X : -0,9911.FB1 -0,9911.FB2 -0,9911.FB3 +XO = 0
/ Y : 0,1152.FB2 -0,1152.FB3 +YO = 0
/ Z : -0,1330.FB1 +0,0665.FB2 +0,0665.FB3 +ZO -12000 = 0
resultant moment theorem :
/ X : 0,0669.FB2 -0,0003.FB3 -1115 = 0
/ Y : 188,3112.FB1 -94,1556.FB2 -94,1556.FB3 +66000 = 0
/ Z : 164,0736.FB2 -163,0825.FB3 = 0
FB1 = 16463,46
FB2 = 16763
FB3 = 16864,87
XO = 49646,1
YO = 11,74
ZO = 11953,37
I can to solve it with pen and paper, but i can't do it with mathcad
I can see that there is a problem with symbolic evaluations
My answers are different from yours. I may have made an error somewhere...
Anyway, you should be able to do this in Prime.
I rewrite first matrix, in second equation , with correct values
But i see a problem in first line
if i solve that
the calculation does not converge ...😓
see attached file
it's strange, i copy paste in new sheet.
If i switch this matrix
The calculus run but it's wrong
if i use the matrix as in picture, the calculus is good
if i switch , it's wrong
For the upper left matrix, the determinant is 0, it means the matrix is singular, or in other words, it cannot be inverted.
That means that lsolve cannot find a solution.
For the lower left matrix that's not the sae, and lsolve can find a solution.
however there are other things that don't work
If i move the Bpoints the geometrical value was changed.
The calculation run
but key result are curious ?
If i calculate this manually, i find approximately:
FB1 = -202569,41
FB2 = -194324,39
FB3 = -194325,75
XO = 584902,22
YO = 0,16
ZO = 13455,71
and the worksheet give
see attached full worksheet (sorry it is written in french)
I have only a vague idea of what your calculations are about.
My responses have been from a(n almost pure) mathematical viewpoint, and knowledge of Mathcad/Prime,
just trying to streamline your calculations and potentially reducing the amount of typing (which is a general source of error).