微机模拟研究金属基复合材料拉伸断裂行为与纤维强度分布的关系

A Computer-Simulation Study on Variation of Tensile Freacturc Behavior with Fibre's Strength Distribution for a Metal-Matrix Composite

纤维强度分布的变动系数CV与金属基复合材料制造工艺、纤维及界面特性等直接相关。本文用微计算机模拟法研究了CV对长纤维增强金属基复合材料拉伸断裂行为的影响,针对某—B/A1复合材料所作模拟结果指出,当其他条件相同,CV≤5％时,材料断裂形式为非累积型;当CV≤15％时,断裂形式为累积型;而当CV值处于5％与15％之间时,表现为两种断裂的混合形式。纤维所能承受的平均应力值随着CV增大而单调减小。

The variation coefficient of fibre's strength distribution, CV, reflects such main factors as the fabrication, fibre and interface featuret of a metalmatirx compostite. Computer-simulation was used in rhe present study to determine the effect of CV on the tensile fracture bebavior of a B/Al unidirectional filamentary composite. The simulation results indicate that with other factors identical, the fracture of the composire is non-cumulative when CV≤5%, cumulative when CV≥15%, and in mixed mode when 5%<CV<15%. The average stress the fibre can withstand decreases montonically as CV increases.