Acoustic stress waves can be guided to follow pre-determined paths in solids, using elastic anisotropy.
Recently, there has been intense interest to design materials and structures that can shield specific regions
within the material by redirecting the incident stress-waves along desired paths. Some of the proposed
techniques involve variable mass density and stiffness. We have designed a material with isotropic mass
density but highly anisotropic elasticity that can guide incident waves along desired trajectories. Harmonic excitations are imposed, and it is shown that the stress-wave energy would travel around a protected central region. The model is also evaluated using numerical simulations, which confirm that majority of the stress-wave energy is guided around the central cavity and is delivered exactly to the opposing face in a location corresponding to the incident excitation location.
Acoustic-wave velocity is strongly direction dependent in an anisotropic medium. This can be used to design
composites with preferred acoustic-energy transport characteristics. In a unidirectional fiber-glass
composite, for example, the preferred direction corresponds to the fiber orientation which is associated with
the highest stiffness and which can be used to guide the momentum and energy of the acoustic waves either
away from or toward a region within the material, depending on whether one wishes to avoid or harvest the
corresponding stress waves. The main focus of this work is to illustrate this phenomenon using numerical
simulations and then check the results experimentally.