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TikkaMasala12-Amethyst
12-Amethyst
March 6, 2020
Question

Iteration with several equations

  • March 6, 2020
  • 9 replies
  • 5567 views

Hello

 

I should somehow solve an parameter with iterating several equations simultaneously.

 

In the attached sheet are to constants, equations and the "to be solved" parameter.

The problem is that I don't know if "Given" "Find" system works for this kind of a problem...

I would prefer a solution using programming i.e. with "Add line" operator,

but I don't know how to program this.

 

Any help is appreciated.

9 replies

F
Fred_Kohlhepp23-Emerald I
23-Emerald I
March 6, 2020

A solve block should solve this, but you've got several problems:

  1. You have some variables with units and there are numbers in your equations without units.  In several places you are raising stress (Pa) to fractional powers.  m_parameter adds a plane number to a number with units (which you cannot do.)
  2. You have an exponential {exp((1.63-9.7/FC-15.7/FC)^2} which evaluates to a constant (3.521), why carry such a complicated expression; or is it wrong?

It looks like you're trying to program an iteration.  I would assume, then, that you would like delta q to go to zero (?)  Can you write simply the condition you want to be an equality?  That's what you need for the solve block.

 

It is possible to iterate (using a very old Mathcad construct.)  Attached is a Prime 4 file and its pdf.

A
AlanStevens19-Tanzanite
19-Tanzanite
March 6, 2020

See the attached for how to structure the system in Mathcad.  However, the results cannot be trusted unless I have guessed the right units for your m.parameter function. You will need to adjust this appropriately.

 

Alan

 

    T
    TikkaMasala12-AmethystAuthor
    12-Amethyst
    March 11, 2020

    Hi Alan

    Your solution appears to work fine for the request that I had. I attached a computation file and

    a pdf with the values using the correct units and the results seem to match with the graph.

     

    The reason why I need an automatic iteration is that the computation should be done to a large number

    of input values. The sheet with the large vectors can be found as attached.

     

    Could you or someone else help to get the iteration program to work for a large number of these input values?

     

    Thank you in advance.

    L
    LucMeekes23-Emerald IV
    23-Emerald IV
    March 11, 2020

    You can define the result of the solve block as a function. That should allow you to use the same solve block for any number of inputs.

    Here is a very small example that should illustrate the method:

    LucMeekes_0-1583936067576.png

    Success!
    Luc

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