二维弹塑性颗粒超材料能量耗散机制和波传播特性的研究

Due to its designability, granular metamaterials have great application prospects in engineering fields, such as impact protection, energy decomposition and redirection propagation, wave tailoring and wave tuning, where conventional materials are difficult to achieve. Most of the existing researches consider the elastic contact deformation between granules, and the effects on the energy dissipation and wave propagation caused by dynamic elastic-plastic contact deformation are less studied. This application project considering the dynamic elastic-plastic contact deformation effect to study the energy dissipation mechanism and wave propagation characteristics of elastic-plastic granular metamaterials. The elastic-plastic contact deformation behavior is analyzed by establishing the collision-contact finite element model of two-dimensional distribution elastic-plastic spherical granules, and the suitable dynamic elastic-plastic contact law for granular metamaterials is proposed. Based on the binary collision approximation theory and the proposed dynamic elastic-plastic contact law, the theoretical calculation method for the wave propagation response of two-dimensional elastic-plastic granular metamaterials is proposed. The energy dissipation and wave propagation characteristics of the two-dimensional elastic-plastic granular metamaterial are tested by building an experimental platform and a test system. The three-dimensional finite element model for wave propagation analysis of two-dimensional elastic-plastic granular metamaterials is built. The numerical calculation, theoretical analysis and experimental test results are used to study the energy dissipation mechanism and wave propagation characteristics. The research of this project can further explore the response of energy and wave propagation of granular metamaterials, and expand the application potentials in engineering.

颗粒超材料因其可设计性，在冲击防护、能量分解与重定向传递、波裁剪和波调谐等常规材料难以实现的工程领域具有巨大的应用前景。已有研究大多考虑颗粒间的弹性接触变形，对动态弹塑性接触变形造成的能量耗散及对波传播的影响效应研究较少。本申请项目拟考虑动态弹塑性接触变形效应，研究弹塑性颗粒超材料的能量耗散机制和波传播特性。通过建立二维分布的弹塑性球形颗粒的碰撞-接触有限元模型，分析弹塑性接触变形行为，提出适用于颗粒超材料的动态弹塑性接触法则。采用二体碰撞近似理论和提出的动态弹塑性接触法则，提出二维弹塑性颗粒超材料波动响应的理论计算方法。通过搭建实验平台和测试系统，测试二维弹塑性颗粒超材料的能量耗散与波动特性。建立二维弹塑性颗粒超材料波动响应分析三维有限元模型，应用数值计算、理论分析和实验测试结果，研究能量耗散机制和波传播特性。本申请项目的研究可进一步探索颗粒超材料的能量与波动响应规律，拓展工程应用潜能。

颗粒超材料因其良好的可设计性和独特的波传播特性，在冲击防护领域有重要应用。本项目针对颗粒超材料冲击问题展开研究。首先，分析了颗粒材料间的动态接触行为，建立了考虑弹塑性变形的接触理论模型。其次，采用理论研究、实验测试和仿真分析方法，研究了摩擦系数、系统缺陷对弹性颗粒超材料冲击波传播的影响，研究了边界构型、材料参数对弹塑性颗粒超材料冲击波传播的影响。研究表明，冲击波在二维弹塑性颗粒超材料中传播比其在弹性颗粒超材料冲传播更为复杂。通过调整摩擦系数、边界构型、材料参数等方式，可实现冲击波幅值及波速的调控。本项目研究丰富了颗粒超材料波动特性研究，将极大促进颗粒超材料在冲击防护领域的应用。