This study describes the dynamic response of a two-dimensional hexagonal packing of uncompressed stainless steel spheres excited by localized impulsive loadings. The dynamics of the system are modeled using the Hertzian normal contact law. After the initial impact strikes the system, a characteristic wave structure emerges and continuously decays as it propagates through the lattice. Using an extension of the binary collision approximation for one-dimensional chains, we predict its decay rate, which compares well with numerical simulations and experimental data. While the hexagonal lattice does not support constant speed traveling waves, we provide scaling relations that characterize the directional power law decay of the wave velocity for various angles of impact. Lastly, we discuss the effects of weak disorder on the directional amplitude decay rates.

中文翻译：

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二维六角形颗粒晶格中的行波。

这项研究描述了由局部脉冲载荷激发的未压缩不锈钢球的二维六边形堆积的动力响应。系统的动力学是使用赫兹法线接触定律建模的。初始冲击撞击系统后，特征波结构出现并随着其传播通过晶格而不断衰减。使用一维链的二元碰撞近似的扩展，我们可以预测其衰减率，并与数值模拟和实验数据进行比较。尽管六边形晶格不支持恒定速度的行波，但我们提供了比例关系，这些关系描述了在各种撞击角度下波速的方向幂定律衰减。最后，