ODE45/ODE15 inquiry about nonlinear spring

Is there anyone can help me on how to get an ODE45/ODE15 program to solve the above equation?

I want to get the value of y1 and y2.

Thanks,

Answer 1

[Star Strider]

Since the system appears to describe a differential-algebraic equation, see the documentation section on Solve Differential Algebraic Equations (DAEs) that describes how to set it up symbolically in order to use ode15i to integrate it numerically.

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[haohaoxuexi1]

Can you provide me with an example with second order derivative?

Thanks,

[Star Strider]

Use the odeToVectorField function. The documentation should provide all the necessary examples.

Answer 2

[KSSV]

You may refer the following links to understand what to do.

https://in.mathworks.com/matlabcentral/fileexchange/33168-springpendulum

https://in.mathworks.com/matlabcentral/fileexchange/33425-bead-on-a-rotating-hoop

https://in.mathworks.com/matlabcentral/fileexchange/33082-simplependulum

[haohaoxuexi1]

Would you mind to take a look at my equation?

I don't have the second order derivative term in equation#1.

And if possible, please tell me how to code it in ODE45/ODE15 to achieve my purpose?

In your example, you have theta and X, both of them have second order derivative term.

Thanks.