25 Reputation

8 years, 257 days

Thank yuo, that worked!...

Thank yuo, that worked!

Thank yuo, that worked!...

Thank yuo, that worked!

Thank you, numeric it is indeed possible...

Thank you, numeric it is indeed possible.

However, when I want to solve an 3-point BVP; dsolve numeric does not work. There are workaround to still solve numerically, but it is also possible to solve symbolically (maybe for a specific range)?

Thank you, numeric it is indeed possible...

Thank you, numeric it is indeed possible.

However, when I want to solve an 3-point BVP; dsolve numeric does not work. There are workaround to still solve numerically, but it is also possible to solve symbolically (maybe for a specific range)?

@Markiyan Hirnyk I don't really und...

@Markiyan Hirnyk I don't really understand how to do it. I have found some examples how to use the shooting method, but nowhere I found an example with multipoint boundary conditions.

@Markiyan Hirnyk I don't really und...

@Markiyan Hirnyk I don't really understand how to do it. I have found some examples how to use the shooting method, but nowhere I found an example with multipoint boundary conditions.

I dont think this is the answer to my pr...

I dont think this is the answer to my problem. What I have is 6 coupled differential equation, which have BC's at the points 0, 100 and 150, which makes is a three-point BVP

I dont think this is the answer to my pr...

I dont think this is the answer to my problem. What I have is 6 coupled differential equation, which have BC's at the points 0, 100 and 150, which makes is a three-point BVP

@JohnS Thank you for your reply. Th...

@JohnS Thank you for your reply. This confirms to me that the solution that Maple finds is correct for these equations. It is not wat I expected, I did not really expected the 2nd derivative to be zero at 0, but certainly I didn't expect it to show a peak to -0.04 like that.

The theory is the thin-shell theory by kirchhoff-love. I have checked the equations multiple times, but they seem correct. Probably there is a problem in this specific boundary condition or I am making a mathematical mistake.

@JohnS Thank you for your reply. Th...

@JohnS Thank you for your reply. This confirms to me that the solution that Maple finds is correct for these equations. It is not wat I expected, I did not really expected the 2nd derivative to be zero at 0, but certainly I didn't expect it to show a peak to -0.04 like that.

The theory is the thin-shell theory by kirchhoff-love. I have checked the equations multiple times, but they seem correct. Probably there is a problem in this specific boundary condition or I am making a mathematical mistake.

@JohnS Thanks for your input. I hav...

@JohnS Thanks for your input. I have tried your advice, but this creates the same output I had before.

@JohnS Thanks for your input. I hav...

@JohnS Thanks for your input. I have tried your advice, but this creates the same output I had before.

@Carl Love Yes you a right, I use c...

@Carl Love Yes you a right, I use cylindrical coordinates. My original differential equation is a two dimensional PDE (the r-dimension is small compared to the other dimensions, so is neglegted). I have eliminated the theta-dependence, by using the orthogonality property of the sin and cos function (I know that the input and output on the theta dimension should be a sin or cos function). This gives me a ODE which I can solve quite simple with Maple.

When I change to cartesian, it will be very hard (impossible?) to eliminate dimensions, so I am bound to solving a PDE, which is not preferred.

I could have made a mistake in the elimination of the theta-dependence. Stange thing is that when I calculate a simply supported beam (same ODE, different BC), the result is very good. I am thinking that maybe when I compose the ODE, the assumptions I make do not apply for every BC.

@Carl Love Thank you for the effort...

@Carl Love Thank you for the effort, yesterday I also tried to nondimensionalize, which gave no result. Maybe the output that maple gives is correct to this BVP.

Could there be a difference of output when I don't use the numeric version of dsolve? My computer does not have enough computational power to calculate it symbolic, so I cannot try.

And I was thinking, is there another program that can solve differential equations like this, just to confirm the output. I tried Matlab and Mathematica, but both give me problems with this differential equation (they don't solve at all)

@Carl Love Thank you for the effort...

@Carl Love Thank you for the effort, yesterday I also tried to nondimensionalize, which gave no result. Maybe the output that maple gives is correct to this BVP.

Could there be a difference of output when I don't use the numeric version of dsolve? My computer does not have enough computational power to calculate it symbolic, so I cannot try.

And I was thinking, is there another program that can solve differential equations like this, just to confirm the output. I tried Matlab and Mathematica, but both give me problems with this differential equation (they don't solve at all)

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