中文摘要：

借助图像处理和识别技术，建立复合材料真实微观结构的有限元模型，并运用该模型分析计算SiCp/2024Al复合材料在应变速率为200～14000 s-1下的动态力学性能。在真实微观结构的有限元模型中，无规则的SiC颗粒自由分布在铝合金基体材料中，SiC颗粒形貌保持原状。有限元模拟结果表明，动态压缩过程中，低体积分数的SiCp/2024Al复合材料流变应力随着应变速率的增加呈现先升高后降低的趋势。在较高应变率下，SiCp/2024Al复合材料流变应力出现降低趋势是由于复合材料内部损失或铝合金基体热软化甚至局部熔化导致的。当应变低于0．62时，带有棱角的SiC颗粒比圆形SiC颗粒强化效果好，当应变大于0．62时，情况正好相反。

英文摘要：

Using the information of image processing and recognition,a microstructure-based finite element model （ FEM） is established to evaluate the dynamic properties of SiCp/2024Al composites at strain rates ranging from 200 to 14 000 s-1.In the microstructure-based model,the irregular SiC particles are randomly distributed in the metal matrix.The results show that the flow stress of SiCp/2024Al composites with low particle volume fraction increases firstly to a maximum value and then decreases with the increasing of strain rate during adiabatic compression.The probable reason for the reduction of flow stress is that the inner damage and the heat softening of composites play a key role in the dynamic behavior of SiCp/2024Al composites at higher strain rates.Moreover,the configurations of SiC particles have dominate influence on the dynamical behavior of SiCp/2024Al composites. In particular,in cases of smaller strain （less than 0.62）, the angular particles have better strengthening effect than those of circle particles,however,in contrast,the strengthening effect of circle particles is more remarkable.