双颗粒几何分布对脆性基复合材料力学性能的影响

Effect of Bi-Particle's Geometrical Distribution on Failure Process of Brittle-Matrix Composites

在材料细观非均匀性的基础上研究了不同几何分布的双颗粒脆性基复合材料的宏观力学性能以及对复合材料破坏机理的影响.结果表明当保持间距不变,双颗粒分布方向垂直于加载方向时,复合材料的韧性最好、峰值强度最低;而与加载方向一致时,复合材料的韧性最差、峰值强度却最大.当颗粒沿着垂直于加载方向排列时,随着颗粒间距减小,复合材料的峰值强度也减小,这主要是颗粒之间的耦合效应造成的;而当颗粒沿着加载方向分布时,颗粒间距的变化对复合材料的峰值强度没有显著影响.颗粒的不同几何分布对材料的弹性模量影响甚微.

MFPA^2D, a numerical programme developed on the basis meso-darnage mechanics, is adopted to simulate the deformation, damage and fracture, i. e., the whole failure process of brittle-matrix composites reinforced by particles under uniaxial tensile load. The effect of bi-particle＇s geometrical distribution is then investigated. From the simulation, a conclusion is drawn that different bi-particle＇s distribution will enable different failure mechanism and, therefore, it has profound effect on the failure mode and strength but less effect on the Young＇s modulus of the composites.