Nonlinear Pulse Propagation through Ordered Granular Networks
Andrea Leonard (ET Zürich), Laurent Ponson (Institut Jean Le Rond d'Alembert Université Pierre et Marie Curie), Chiara Daraio (ET Zürich)
Mechanics and Dynamics of Periodic Structures
Wed 9:00 - 10:30
Salomon 101
We study the dynamic force transmission through 2D and 3D ordered networks of interconnected chains of particles thanks to experimental, numerical and theoretical investigations. This work builds on the well-studied phenomenon of solitary wave propagation in 1D granular chains of particles. The unique behavior of the compact pulses, or solitary waves, traveling through the networks allows us to derive theoretical expression for the pulse splitting, bending, and combining, by modelling traveling pulses with effective particles possessing identical momentum and kinetic energy. Additionally, we use a discrete particle model to numerically simulate the nonlinear dynamic behaviour of each system for comparison with experiments and theoretical predictions. In the present study, a single branching angle was chosen for each system, 2D and 3D, to maximize the force transmission, while maintaining experimental feasibility. The experimental results are in good agreement with both numerical simulations and theoretical predictions based on the quasi-particle model. We observe an exponential decay in the leading pulse amplitudes, both with distance from the impact (with respect to branching level, N) and in the distribution of leading pulses perpendicular to the line of impact (at a given branching level, N). The rapid amplitude decay exhibited by these granular networks makes them highly attractive for impact mitigation applications. Additionally, the observed exponential decay can be related to the dynamic load transfer along force chains in disordered granular media described in recent studies3. This work provides both insight into the behaviour of natural granular pilings and demonstrates the potential for controlling wave propagation pathways through material design.