topic Non linear equation solution with data function in Mathcad

Non linear equation solution with data function

smilani — Thu, 03 May 2018 13:19:30 GMT

Dear All,

I need to solve a non linear equation in mathcad 15.

Input

After a physical test, I obtain the Mbase and phi value, that I use to determine mu trend (right graph).

I after need to use the mu function in a non linear equation, to determine the equilibrium configuration of the structure.

NL equation

How can I use the mu(phi) function in the NL equation? if I set mu as constant I don't have any problem.

I have a problem with mathcad file attach.

Best regards

Stefano

Re: Non linear equation solution with data function

terryhendicott — Sat, 20 Jan 2018 12:48:07 GMT

To include the mathcad file you need to zip it first.

Re: Non linear equation solution with data function

smilani — Sat, 20 Jan 2018 12:53:37 GMT

Thanks,

I attach zip file

Re: Non linear equation solution with data function

-MFra- — Sat, 20 Jan 2018 16:56:33 GMT

Hi,

Re: Non linear equation solution with data function

smilani — Sat, 20 Jan 2018 16:48:50 GMT

Dear MR,

thanks for your reply.

I don't need to find the solution in previous point, but I would like to define a mu function from where the non linear equation catch the value for the numerical solution.

The mu parameter is not constant but vary with the rotation (phi), so I need to create a spreadsheet that automatically iterate the mu function.

If the function was defined, I don't have any problem, but in this case, the function is defined by data points, and I need to interpolate this value to solve the NL equation.

Best regards

Stefano

Re: Non linear equation solution with data function

smilani — Sat, 20 Jan 2018 17:15:11 GMT

For example:

NL solution

Now mu is a function of phi and the NL solution is reported in the previous picture.

I don't know how can I create the mu function by data point that can be used in the NL equation.

Best Regards

Stefano

Re: Non linear equation solution with data function

-MFra- — Sat, 20 Jan 2018 17:38:09 GMT

Hi Stefano,
I'm on the right track? it seems to be just what you are looking for.

Re: Non linear equation solution with data function

smilani — Sat, 20 Jan 2018 17:23:05 GMT

Yes absolutely,

I need a function to implement into the NL equation.

Your procedure is really interesting, but if is easier for you, we can use a linear interpolation beetwen the data points.

This case is an example, in pratice I have many other points.

Thanks again

Stefano

Re: Non linear equation solution with data function

-MFra- — Sat, 20 Jan 2018 18:00:14 GMT

Re: Non linear equation solution with data function

smilani — Sat, 20 Jan 2018 18:00:13 GMT

Can you share the mathcad file?

Now I try to understand the programming command.

Thanks and best regards

Stefano

Re: Non linear equation solution with data function

-MFra- — Sat, 20 Jan 2018 18:15:15 GMT

Here is the worksheet.
Greetings FM

Re: Non linear equation solution with data function

smilani — Sat, 20 Jan 2018 18:27:47 GMT

I have problem to understand the logic command of this point

Can you please explain me more?

Best regards

Stefano