微孔结构对PMI泡沫准静态压缩性能的影响

摘要

基于BBC点集建立了聚甲基丙烯酰亚胺(PMI)闭孔泡沫的Kelvin十四面体模型和Laguerre模型,并采用有限元方法研究了其在准静态载荷作用下的压缩性能.分析了孔径大小、泡孔体积离散系数对压缩弹性模量、初始峰值应力和能量吸收能力的影响.结果表明:Kelvin十四面体模型可以较好地预测PMI泡沫的压缩弹性模量和峰值应力;在相同相对密度条件下,小孔径泡沫的初始峰值应力和能量吸收能力均高于大孔径泡沫,而压缩弹性模量则低于大孔径泡沫;随着泡孔体积离散系数的增大,闭孔PMI泡沫压缩弹性模量、初始峰值应力和能量吸收能力均减小.%On the basis of the BBC points set,the Kelvin tetrakaidecahedron and Laguerre tessellation models for the polymethacrylimide (PMI) closed-cell foam were established.The quasi-static compression performance was analyzed by finite element method.The effects of cell size and cell volume dispersion on compression modulus,initial peak stress,and energy absorptivity were discussed.Numerical results showed that the tetrakaidecahedron model can predict the compression elastic modulus and initial peak stress of the PMI foam quite well.Under the same relative density,the smaller cell size will lead to higher initial peak stress and higher energy absorption capacity,but lower compression elastic modulus.The compression elastic modulus,initial peak stress and energy absorption capacity of the closed-cell PMI foam decreases with the increasing cell volume dispersion.