短纤维增强脆性基复合材料破坏过程和力学性能研究

 研究短纤维增强脆性基复合材料在单轴拉伸荷载下的力学性能和破裂机理。采用基于细观损伤力学基础上开发的针对材料破坏过程的数值分析软件，考虑材料细观非均匀性，对复合材料的变形、损伤直至失稳破坏的全过程进行数值模拟。结果表明，加入短纤维后，材料试件的强度和韧性都比基体材料显著提高。短纤维强度的变化对复合材料试件的强度和刚度没有明显影响；而短纤维弹性模量的变化对复合材料试件的强度、刚度和韧性均影响明显，随着短纤维弹性模量的增加，复合材料试件的强度和刚度不断增加，但韧性却逐步降低。

Effect of Short Fibers Mechanism on Macro Properties of Composites

The failure mechanism and mechanical property of a brittle composite matrix, reinforced with short fibers under the uniaxial tensile load, have been studied. A numerical program developed based on meso-damage mechanics and with consideration of heterogeneousness is adopted to simulate the whole failure process of the fiber reinforced composite including transformation, damaging and cracking down. From the simulation result, the strength and toughness of the composite increase sharply when it is added with short fibers. However there is little affect on the strength and toughness of the composite when the strength of short fibers changes. When the elastic modulus of fibers is different, the strength and the toughness even the stiffness of composite are influenced greatly. Moreover, strength and stiffness enhance, while toughness reduces with the increasing elastic modulus.