Highly nonlinear solitary wave propagation in y-shaped granular crystals with variable branch angles

We study the propagation of highly nonlinear wavesin a branched (Y-shaped) granular crystal composed of chains of spherical particles of different materials, arranged at variable branch angles. We test experimentally the dynamic behavior of a solitary pulse, or of a train of solitary waves, crossing the Y-junction interface, and splitting between the two branches. We describe the dependence of the split pulses’ speed and amplitude on the branch angles. Theoretical predictions based on quasi-particle model and numerical simulations based on Hertzian interactions between the particles are found in agreement with the experimental data.