随机源对颗粒增强金属基复合材料力学性能影响的多尺度分析及实验验证

Multi-scale analysis of effect of uncertainties on mechanical properties of particle reinforced metal matrix composites and experimental validation

20%(体积分数)SiC_(p)/2009Al复合材料的准静态拉伸实验结果表明,其失效应变等力学参数具有明显的分散性。采用多尺度有限元的方法研究了两类随机源对20%SiC_(p)/2009Al宏观力学性能的影响。通过对一系列含随机源的细观多颗粒代表体积单元模型进行准静态拉伸模拟,得到了材料失效应变和断裂能各自的随机分布特征及两者之间的相关性特征,然后结合宏观试样模型,实现了实际材料内不同区域材料性能随机性的表征。研究表明,宏观有限元结果与实验数据的吻合性较好,且由于考虑了随机源的影响,宏观有限元结果还能够很好地模拟失效应变等的分散性特征。

The results of quasi-static tensile experiments on the 20%(volume fraction)SiC_(p)/2009Al composite show a significant dispersion of the mechanical properties such as failure strain.The effects of two uncertainties on macroscopic mechanical properties of the composite were investigated using a multiscale finite element approach.The distribution characteristics of failure strain and fracture energy,and their correlations were obtained from FE simulations of a series of mesoscale RVE models.Then combined with the macroscale model,the randomness of mechanical properties in various regions within the actual material can be characterized.The results of the quasi-static tensile simulations of the macroscale model show good agreement with the experimental results,and are also able to simulate the dispersion behavior of failure strain very well due to the introduction of material stochasticity.