颗粒固体弹性势能的声波性质

Properties of sound waves in granular matter analyzed by an elastic potential model

基于大量静止颗粒堆积而成的物体属于非线性弹性体的观点,计算了其弹性势能的声速表达式(考虑圆柱对称和沿主应力方向传播的平面波情形).通过与己报道的一些实验数据的对比,认为精密的声学方法能够测定势能中的所有材料参数,因此是研究这类材料非线性弹性行为细节的一个重要观测手段,但需要对样品的所有应力、密度和均匀程度进行全面仔细的监控.

According to the point of view that static dense granular matter is a nonlinear elastic body, we derive an analytic sound speed expression given by its elastic potential, for the case of samples with cylindrical symmetry and sound waves propagating in the directions along and perpendicular to the symmetry axis. By a detailed comparison of the expressions with experiments reported in the literature, we conclude that the acoustic method can determine all material parameters appearing in the elastic potential accurately, which provides us with an important way of studying detailed nonlinear elasticity behaviors of granular materials, if stresses, density, and their uniformity of samples are thoroughly controlled and measured.