Existence of Longitudinal Waves in Anisotropic Media
I. I. Kolodner · The Journal of the Acoustical Society of America · 1966
Recent papers demonstrated the existence of longitudinal waves in a linear, homogeneous, anisotropic elastic medium (in two distinct directions), and that the same argument applies to materials having “positive longitudinal elasticity.” Here, we give another proof of the same fact, and establish a bit more: there exist at least three distinct directions along which longitudinal waves will propagate.