Multilayer structures have found extensive applications in personal protection engineering, which are considered effective materials in mitigating shock loads. In this paper, the effect of layer thickness and layout on the shock mitigation performance of multilayer structures is evaluated experimentally, and the mitigation mechanism is analyzed. The tested structures are designed into three groups, composing of four protection materials, including ultra-high molecular weight polyethylene composite (PE), wooden laminated composite (Wood), polyurea (PU), and expanded polyethylene foam (Foam). In the experiment, a pressure test platform is developed to measure the transmitted shock pressure pulse after passing through the structure, and the tested structure supported by the platform is subjected to the shock loads generated by a shock tube facility. Experimental results indicate that the transmitted pressure amplitude can be considerably reduced by increasing the thickness of the Foam layer. Besides, with the same thickness, when the Foam layers are staggered and arranged within the structure, the transmitted pressure amplitude is much higher than that of when they are entirely arranged as the back layer within the structure. Further, a new energy transmission model is proposed to reveal the shock mitigation mechanism, which considers that the output energy transmitted into the target is generated jointly by the input energy from the shock loads and the energy transmission efficiency of the structure. The specific energy values are quantitively calculated through numerical simulation. Results indicate that for different layer layouts of designed structures, the energy transmission efficiency changes little, but the input energy varies a lot. Arranging the Foam layers as the back layer within the structure can reduce their compressed deformation under shock loads, which contributes to much less input energy and better mitigation performance.

多层结构已在个人防护工程中得到广泛应用，被认为是减轻冲击载荷的有效材料。本文通过实验评估了层厚和布局对多层结构减震性能的影响，并分析了减震机理。将测试的结构分为三组，由四种保护材料组成，包括超高分子量聚乙烯复合材料（PE），木质层压复合材料（Wood），聚脲（PU）和发泡聚乙烯泡沫（Foam）。在实验中，开发了一种压力测试平台，以测量穿过结构后传递的冲击压力脉冲，并且由平台支撑的被测试结构要承受由冲击管设备产生的冲击载荷。实验结果表明，通过增加泡沫层的厚度可以大大降低传递的压力幅度。此外，在相同厚度的情况下，当泡沫层交错排列在结构内时，传递的压力幅度远大于将泡沫层整体作为背层布置在结构内时的传递压力幅度。此外，提出了一种新的能量传递模型来揭示减震机理，该模型认为传递到目标中的输出能量是由来自冲击载荷的输入能量和结构的能量传递效率共同产生的。通过数值模拟定量地计算比能量值。结果表明，对于设计结构的不同层布局，能量传输效率变化不大，但输入能量变化很大。将泡沫层安排为结构内的背层可以减少其在冲击载荷下的压缩变形，从而有助于减少输入能量并提供更好的缓解性能。