成层式防护结构中分散层研究综述

成层式防护结构通常由伪装层、遮弹层、分散层和主体结构组成，现已被广泛应用于地面、浅埋以及坑道口部的防御工事中。其中分散层作为降低侵彻后爆炸毁伤效应的功能单元，其作用机理主要包括:借助波阻抗失配效应以降低向下部结构传播的能量占比、延长应力波传播路径；利用分层界面产生面波以改善荷载集中状态；通过基体材料不可逆塑性破坏以吸收耗散冲击波能量；增大结构阻尼以减轻主体结构震动效应。开展分散层的相关研究，对提高工程整体防护水平具有重要的现实意义。基于此，从分散层材料与结构型式两个方面较为系统地介绍了国内外成层式防护结构中分散层的研究现状，分析了分散层的结构及物性参数对其防护效能的影响，提出分散层选型及设计需关切的几点问题，并对目前分散层研究中存在的问题进行了探讨与展望，以期为今后分散层的研究发展提供参考。

A review of sacrificial claddings in multilayer protective structure

The multilayer protective structure has been widely used in fortifications located above-ground, shallow burial, and tunnel entrances. And this type of structure usually consists of four parts: camouflage layer, shelter layer, sacrifice layer and protection structure. Among them, the sacrifice layer is the main functional unit to reduce the damage effect of strong explosion after penetration. Its action mechanism mainly includes: reducing the proportion of energy propagating to the substructure and extending the propagation path of stress wave by means of the wave impedance mismatch effect; using the layered interface to generate surface waves to reduce the load concentration; absorbing and dissipating shock wave energy through irreversible plastic failure of the matrix material; increasing the structural damping to reduce the vibration effect of the protection structure. Thus, it is of great practical significance to carry out relevant research to improve the overall level of engineering protection. Taking the materials and structure of sacrifice layer as clues, the current status of research on sacrifice layer in multilayer protective structure at home and abroad is systematically sorted out. On this basis, the influence of structural parameters such as the density, wave impedance, thickness, unit shapes and sizes, moisture content and other physical parameters of the sacrifice layer on the protective performance is analyzed. Moreover, several issues that need to be considered in the selection and design of the sacrifice layer are proposed. The perfect sacrifice layer should be economical, reliable, and have a low wave impedance, sufficient static compressive strength and a certain yield strength, which be able to undergo a large plastic deformation under the condition that the yield stress remains essentially constant. Finally, the problems existing in the current research on the sacrifice layer are discussed and prospected, in order to provide a reference for the research and development of the sacrifice layer in the future.