MATLAB Central Newsreader - Acoustic wave propagation in thin plates

Acoustic wave propagation in thin plates

Johan Carlson — Fri, 21 Nov 2008 18:10:18 -0500

Hey guys,

Does anyone know of any MATLAB solution/implementation of acoustic wave propagation in a finite thin plate.

I'm looking for a solution that can calculate the impulse response of a rectangular plate of dimensions Lx, Ly, Lz, where Lz is the thickness.

Ideally I'd like to know the impulse response of the plate for an impulse excitation at (x0,y0,z0) and an observation point at (x,y,z).

I have a solution including the p-wave, but need to incorporate more wave modes (Lamb modes).

Any ideas, pointers to literature on the subject, etc. would be very much appreciated.

Best regards,
/JC

Re: Acoustic wave propagation in thin plates

Matt Fig — Fri, 21 Nov 2008 18:36:02 -0500

The classic book by Graff has theoretical results for waves in plates and shells, including Lamb waves if I remember correctly.
Also, you don't describe the boundary conditions of interst, but I have written a Matlab program that may be useful to you if you want to explore the eigenvalue problem.

http://www.mathworks.com/matlabcentral/fileexchange/11399

Good luck.

Re: Acoustic wave propagation in thin plates

Johan Carlson — Fri, 21 Nov 2008 19:01:51 -0500

"Matt Fig" <spamanon@yahoo.com> wrote in message <gg6v2i$hsh$1@fred.mathworks.com>...
> The classic book by Graff has theoretical results for waves in plates and shells, including Lamb waves if I remember correctly.
> Also, you don't describe the boundary conditions of interst, but I have written a Matlab program that may be useful to you if you want to explore the eigenvalue problem.
>
> http://www.mathworks.com/matlabcentral/fileexchange/11399
>
> Good luck.

Thank you!

I will check out your program first, and see if it can help me.

The boundary conditions are (dp/dx)=0 at x=0 and x=Lx (the x size of the plate), and then similarly for the other derivatives. p is p(x,y,z,t), i.e. the pressure wave.

I then assume the initial condition p(x,y,z,0) = dirac(x-x0)dirac(y-y0)dirac(z-z0), i.e. a unit impulse at some location (x0,y0,z0). dp/dt at time t=0 is assumed to be zero.

/JC