界面性质对颗粒增强复合材料力学性能和破裂过程的影响

Influence of Interface Characteristic on Failure Process and Mechanical Properties of Brittle Composite Matrix with Particle Reinforcement

界面的力学性质对复合材料的力学特性和破裂机理具有非常重要的影响。研究了具有不同强度界面的颗粒增强脆性基复合材料在单轴拉伸荷载下的力学性能及其破坏过程。从细观尺度考虑了各相材料力学参数的非均匀分布,采用基于细观损伤力学开发的针对材料破坏过程分析的MFPA2D数值模拟程序,对复合材料从裂纹萌生、扩展直至失稳破坏的全过程进行数值模拟。结果表明,当界面结合较强时,复合材料的强度较高但韧性较差;当界面结合较弱时,复合材料的强度较弱而韧性较强,说明较强的界面可有效传递荷载,而较弱界面可增加复合材料的韧性。

Mechanical properties of interface have significant effect on the composite and its final fracture mechanism. To understand such effect, the failure process of particle reinforced brittle composite with interfaces in different strengths has been studied under uniaxial tensile load, while inhomogeneity in mesoscale is applied to the matrix, particles and interfaces, respectively. Furthermore, MFPA^2D, a numerical code developed based on mesodamage mechanics, is adopted to simulate the failure process, i. e, crack initialization, coalescence, propagation and final rupture under uniaxial tensile load. The results show that （a） the composite would have a higher strength and lower toughness while the interface was strong, and （b） on the other hand, while the interface was weak, the composite would have a weaker strength but a higher toughness. It is concluded that the strong interface could transfer the load effectively while the weak one could improve the toughness of the composite.