基于Al/PTFE真实细观特性统计模型的宏观力学性能模拟

Simulation on mechanical properties of Al/PTFE based on mesoscopic statistical model

通过细观力学有限元方法对Al颗粒增强聚四氟乙烯(Al/PTFE)复合材料的宏观力学性能进行了研究,基于Al颗粒粒径分布统计规律及通过SEM对该复合材料孔洞含量的统计分析,在细观层次上建立了考虑颗粒和孔洞位置和尺寸分布的随机代表性体积单元(RVE),借助ABAQUS有限元软件,对二维平面应变和三维实体模型在单轴压缩载荷作用下的力学行为进行了数值仿真;并施加了周期性边界条件(PBC)以提高数值计算结果的准确性。此外,分析了不同颗粒含量下复合材料准静态应力-应变关系,重点对细观有限元模型与准静态压缩试验结果进行了对比分析。研究结果表明:二维和三维2种模型均能较好地模拟Al/PTFE的宏观力学性能,且二维模型较三维模型计算效率更高,并进一步证实了PBC的正确性和有效性。

Macro mechanical behavior of Al particles reinforced polytetrafluoroethylene（Al/PTFE）was studied by finite element method.According to statistics on Al particles and microvoids by SEM,representative volume element（RVE）models considering particles and microvoids distribution as well as geometry were reproduced.By using ABAQUS finite element software,mechanical behavior under uniaxial compression of both two dimension and three dimension models were simulated.Also periodic boundary condition（PBC）was applied to improve accuracy of calculation.Quasistatic stress-strain curves of composites of various particle fractions were analyzed,and especially results from simulations and experiments were compared.The results indicate that both two dimension and three dimension models are effective methods to predict the mechanical behavior of Al/PTFE,and two dimension models are more efficient.Furthermore,the validity and effectiveness of the PBC are verified.