dispersion

  I wanna get the dispersion relation of acoustic crystals in ABAQUS, so far as I know, the frequencies can be obtained by applying different wave vectors in the IBZ, but I dont know how to opperate in ABAQUS, in what way can we simulate the wave vectors (or the cooresponding wave length) . By applying force or displacement, or acceleration ?

 Attacthed, should I model the whole structure or just the 1st BZ? If the 1st BZ is employed, should the periodic semmetric B.C. be considered in my model?

Any suggestion is appreciated! 

As you may know wave propagation in circular cylinders is dispersive. As shown by Pochhammer, there
could be several different modes propagating in an infinite cylinder with
different wave speeds. I'm modeling wave propagation in a finite 3D circular cylinder in

LS-DYNA with solid elements and I'm applying a sinusoidal pressure along

How does one calculate the phonon dispersion relations from the output of a molecular dynamics simuation? 

I have successfully calculated the complete phonon density of states using a fourier transform of the velocity autocorrelation function, but I am still confused as to how to calculate the particular phonon dispersion curves.

Thank you.