泡孔微结构对弹性泡沫材料宏观压缩力学性能的影响分析

EFFECTS OF MICROSTRUCTURE ON THE LARGE COMPRESSION BEHAVIOR OF RUBBER FOAMS

弹性泡沫材料是一类典型的非均质多孔材料,其宏观力学特性取决于基体材料特性和细观组成。通过构造一系列泡孔规则分布、朝向随机的椭圆形泡孔模型,以及随机分布圆形泡孔模型,采用有限元方法分析了弹性泡沫材料细观变形机制,以及泡孔形状、泡孔分布以及孔隙率等因素对弹性泡沫材料宏观压缩力学性能的影响规律。细观力学模型计算结果表明,弹性泡沫材料的单向压缩应力—应变曲线表现出泡沫材料共有的三阶段变形特性;与椭圆形泡孔模型相比,圆形泡孔模型具有较长的压缩平台段和稳定的力学性能;制备规则分布的球形泡孔结构是弹性泡沫材料微结构设计的优选方案。研究结果可用于指导弹性泡沫微结构设计。

As a type of typical cellular foams, the macro-mechanical performances of rubber foams are mainly determined by its micro-structure and cell material properties. In the work reported here, several two dimensional （2D） finite element （FE） models having regularly and randomly arranged elliptical and circular ceils were constructed. The effects of cell shapes, cell distributing, and porosities on the hyperelastic large compressive deformations of rubber foams were explored. Obtained FE analysis results show that the compressive stress-strain curves of rubber foams present three deforming regions. The compressive stress-strain curves of circular cell models have longer plateau stage than those of elliptical cell models, and circular cell models have more steady mechanical performances than elliptical cell models do. If worked as shockproof cushions, circular cell structures are thus better than elliptical cell structures.