Proceedings of The Royal Society A - LaTeX Template.zip from Elastic waves in particulate glass-rubber mixtures

We investigate the propagation of waves in dense static granular packings made of soft and stiff particles subjected to hydrostatic stress. Physical experiments in a triaxial cell equipped with broadband piezoelectric wave transducers have been performed at ultrasound frequencies. The time of flight is measured in order to study the combined effect of applied stress and rubber content on the elastic properties of the mixtures. The bulk stiffness deduced from the wave speed is nonlinear and non-monotonic with the increasing percentage of rubber with a more prominent effect at higher pressures. Moreover, in the frequency domain, a spectral analysis gives insights on the transition from a glass- to a rubber-dominated regime and the influence of rubber particles on the energy dissipation. Mixtures with rubber content below 30% show enhanced damping properties, associated with slightly higher stiffness and lighter weight.

本研究针对受静水应力作用、由软质与硬质颗粒构成的致密静态颗粒堆积体，探究其内部的波传播特性。本研究采用配备宽带压电波换能器的三轴压力室，在超声频段开展物理实验。通过测量波的飞行时间，探究外加应力与橡胶颗粒占比对该混合体系弹性特性的联合影响。由波速推导得到的体积刚度，随橡胶颗粒占比提升呈现非线性且非单调的变化规律，且在更高压力下该变化更为显著。此外，在频域层面，频谱分析可揭示体系从玻璃态主导向橡胶态主导的转变过程，以及橡胶颗粒对能量耗散的影响机制。橡胶颗粒占比低于30%的混合体系，其阻尼性能得到提升，同时伴随刚度小幅提升与质量轻量化的特性。