Non linear equation solution with data function

[smilani]

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

[terryhendicott]

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

[smilani]

Thanks,

I attach zip file

[-MFra-]

Hi,

[smilani]

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

[smilani]

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

[-MFra-]

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

[smilani]

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

[-MFra-]

[smilani]

Can you share the mathcad file? 

Now I try to understand the programming command.

Thanks and best regards

Stefano

[-MFra- · Accepted solution]

Here is the worksheet.
Greetings FM

[smilani]

I have problem to understand the logic command of this point

Can you please explain me more?

Best regards

Stefano