碳化硅颗粒增强铝基复合材料有效弹性模量预测

Prediction of Effective Elastic Modulus for SiC Particle Reinforced Aluminium Matrix Composites

为了分析碳化硅颗粒增强铝基复合材料细观结构对其宏观力学性能的影响,针对无压渗透法制备的A356/SiCp复合材料建立了表征其细观结构的2维代表性体积单元有限元模型,以建立复合材料宏观性能与细观结构之间的依赖关系。在周期性边界条件和模拟单轴拉伸边界条件下研究了颗粒的形状(圆形、椭圆形)和体积分数(10%、15%、20%)对其有效弹性模量的影响,并与无压渗透法制备的A356/SiCp复合材料试验值进行比较。结果表明:在2种条件下的预测结果相差不大,预测误差均不超过5%;碳化硅颗粒体积分数对复合材料的力学性能影响显著,对颗粒形状的影响很小,在相同边界条件及体积分数下,圆形和椭圆形颗粒的预测值相差不超过0.4%。

In order to analyze the influence of microstructure on macro mechanical properties for SiC particle reinforced Aluminium matrix composite,a two-dimensional RVE(Representative Volume Element)finite element model was established to characterize the micro⁃structure of A356/SiCp composite prepared by pressureless infiltration method.The relationship between the macro mechanical properties and the microstructure of the composites was established by RVE finite element model.The effects of particle shape(circle,ellipse)and vol⁃ume fraction(10%,15%,20%)on the effective elastic modulus of A356/SiCp composites were studied under periodic boundary conditions and uniaxial tension boundary condition,and compared with the test values of A356/SiCp com-posites prepared by pressureless infiltra⁃tion method.The results show that the prediction results under the two conditions are almost the same and the prediction error is less than 5%.The volume fraction of SiC particles has a significant effect on the mechanical properties of the composites,but has little effect on the shape of the particles.Under the same boundary conditions and volume fraction,the difference between the predicted values of circular and elliptical particles is not more than 0.4%.