中文摘要：

本文构建了开孔泡沫铝的简化几何模型，并利用有限积分法模拟了具有单层元胞结构的金属泡沫材料在线性极化平面波垂直入射情况下的透射率。基于菲涅耳一基尔霍夫衍射理论分析了孔隙率、孔径尺寸、材料厚度和骨架结构对金属泡沫材料辐射特性的影响。当尺度参数较大时，金属泡沫材料的固相支架结构满足良导体条件，宏观电磁屏蔽效应显著，金属泡沫材料呈现“非透明”性质。随着入射电磁波波长逐渐接近于孔径尺寸，散射效应越来越显著，金属泡沫材料的“半透明”性质开始显现，不同孔隙率的金属泡沫材料的透射率以相近的规律随波长变化。随着波长的进一步减小，衍射效应对于金属泡沫材料透射特性的影响逐渐占据主导地位，采用菲涅耳-基尔霍夫衍射理论可以较好地描述透射能流在孔隙结构内的分布。当衍射效应占据主导地位时，对于相同孔隙率金属泡沫材料，孔径尺寸对衍射光学行为影响不大，而材料厚度、孔隙率和骨架结构会显著影响金属泡沫材料的透射率。

英文摘要：

Simplified geometric model of open-cell aluminum metal foams is developed in this article. The transmittance of unit cell of metal foams with single layer cellular structure normally illuminated by linear polarized plane wave is obtained using Finite Integral Method. Based on Fresnel-Kirchhoff diffraction theory, influence of porosity, pore size, thickness and ligament structure on radiative properties of metal foams is analyzed. As the wavelength of incident electromagnetic wave approaches the pore size, scattering effect becomes significant and translucency of metal foams tends to emerge. Transmittance of metal foams of different porosity varies along similar trend. As the wavelength decreases further, influence of diffraction effect on transmittance of metal foams becomes dominant, and distribution of diffraction energy flow in pore structure can be approximately described using Fresnel-Kirchhoff diffraction theory. In the case of diffraction effect predominating in the energy transfer, influence of pore size on diffraction behavior is negligible for metal foams with the same porosity, while thickness, porosity and ligament structure place significant influence on transmittance of metal foams.