Weak waves under periodic load applied to a packing of glass balls

Based on the tests of packings of calibrated glass balls with a diameter of 1 mm, it is shown that multiple point impacts improve waveguide characteristics of the medium—conducting paths composed of force “chains” emerge in the test material. The further quasi-static alternating shears change the packing of particles, break the chains and reduce conduction. If continued onward, the multiple impulsive loading results in recovery of the “chains” and in better conduction of the paths.