mixed derivatives, I coulnt understand how can I solve ıf there are two kind derivatives

Hi ;

I have to solve this equation and u'' and v'' are the second order derivatives of longitudinal and transverse displacements along X axial ;

u^^ nad v^^ are second order derivatives versus time ( I used ^ instead . )

-pAu^^ +EA(u'+1/2*(v')^2)'=-EAu''
-pAv^^-(EIv'')''+pI(v^^)''+[EA(u'+1/2(v')^2)']v'=-EIv''

[KSSV]

Read this: https://in.mathworks.com/help/symbolic/solve-a-system-of-differential-equations.html

[Bjorn Gustavsson]

You have some sort of partial differential equation. Instead of writing it like that use the latex-capability to write the equations as proper equations. That will help others to see what type of problem you have - I couldn't figure out whether this was a steady-state or time-dependent PDE.

[John D'Errico]

You won't find analytical solutions. So use one of the many methods to find and characterize numerical solutions of PDEs. Which probably means you need to do a lot of reading, before your fingers ever write any code.

Answer 1

[Gloria]

[Bjorn Gustavsson]

Well, to reiterate John D'Ericco's previous comment: You first have to have some fundamental understanding of the type of equation you're about to work with, to reach that you have to do some reading. My general suggestion for the "first stab" information-gathering is to look up what wikipedia has to say about this topic: wikipedias top-page in PDEs

[Gloria]

Ok. Thank you so much.