Hello Carl,

I was wondering why maple supplies us with two solutions for the differential equation. Is it because of the square root in the system? Furthermore, what is the origin of the complex part of the solution?

Cheers,

Feicko

Hello Carl,

I was wondering why maple supplies us with two solutions for the differential equation. Is it because of the square root in the system? Furthermore, what is the origin of the complex part of the solution?

Cheers,

Feicko

Dear Carl Love,

Thank you for your input. I am glad to see that there is a way to get this catenary line in a plot.

While trying your solution, I noticed that my maple gives me a higher order of the complex part of the solution (E-6). Furthermore I cannot plot my solution due to the following error:

Error, (in plot) incorrect first argument [668.0144406*cosh(0.1496973627e-2*x-3.080071554)-7283.340455, -6275.33*cosh(0.149697e-2*x)+6275.32-6239.68*sinh(0.149697e-2*x)]

Furthermore I get an error trying to find the slope of the catenary at x=0.

Can you help me?

Kettinglijn_hoge_waa.mw

Dear Carl Love,

Thank you for your input. I am glad to see that there is a way to get this catenary line in a plot.

While trying your solution, I noticed that my maple gives me a higher order of the complex part of the solution (E-6). Furthermore I cannot plot my solution due to the following error:

Error, (in plot) incorrect first argument [668.0144406*cosh(0.1496973627e-2*x-3.080071554)-7283.340455, -6275.33*cosh(0.149697e-2*x)+6275.32-6239.68*sinh(0.149697e-2*x)]

Furthermore I get an error trying to find the slope of the catenary at x=0.

Can you help me?

Kettinglijn_hoge_waa.mw

@Preben Alsholm 

Looking at w1 I see that this function's maximum will have a part that is a real number and a part that is a multiple of F. When you set this maximum equal to 1.43e6 you will have to subtract the constant part of this maximum from 1.43e6 before deviding by the multiple of F, finally finding the value of F. Or do I misunderstand something?

Cheers,

Feicko

@Preben Alsholm 

Looking at w1 I see that this function's maximum will have a part that is a real number and a part that is a multiple of F. When you set this maximum equal to 1.43e6 you will have to subtract the constant part of this maximum from 1.43e6 before deviding by the multiple of F, finally finding the value of F. Or do I misunderstand something?

Cheers,

Feicko

@Preben Alsholm 

Thank you for thinking with me here. This would be an elegant solution if sm were a multiple of F. But in fact sm consists of a constant and a multile of F. In order to find F an expression is needed where sigma_t can be set equal with a function of F with no other variables. Is there a way to do this?

Thank you so much for your efford,

Feicko

@Preben Alsholm 

Thank you for thinking with me here. This would be an elegant solution if sm were a multiple of F. But in fact sm consists of a constant and a multile of F. In order to find F an expression is needed where sigma_t can be set equal with a function of F with no other variables. Is there a way to do this?

Thank you so much for your efford,

Feicko

Thank you for your respons Preben.

I was checking out your solution, and though it is does a great job in finding the x value corresponding to the maximum, it does not provide us with an answer for F.

The whole point of the equation I wrote was to equal sigma_max (the maximum of this expression) with sigma_t, finding a corresponding value for F.

Is there a way to maximize this expression without assuming a value for F, equalizing the result to sigma_t, and solving this equation for F?

Cheers,

Feicko

Thank you for your respons Preben.

I was checking out your solution, and though it is does a great job in finding the x value corresponding to the maximum, it does not provide us with an answer for F.

The whole point of the equation I wrote was to equal sigma_max (the maximum of this expression) with sigma_t, finding a corresponding value for F.

Is there a way to maximize this expression without assuming a value for F, equalizing the result to sigma_t, and solving this equation for F?

Cheers,

Feicko

Download Berekening_ijslast_d.mw

I rechecked my calculations and figured that the problem might have to do something with the fact that there are two variables in the term that has to be maximized. Perhaps part of the solution coulb be 'assuming' F as a positive?

https://www.dropbox.com/s/mn662fdol14azgl/Berekening%20ijslast%20dv2.mw