颗粒增强镁基复合材料细观力学场的数值模拟分析

本文借助有限元数值模拟,研究了颗粒增强镁基复合材料的细观力学特征.结果表明,等效应力、应力球量、功耗、最大主应力和最大主应变存在明显的集中现象.尽管外力小于基体的屈服强度,但应力集中可使基体发生微区屈服.复合材料主要的失效形式为界面脱粘和基体开裂,同时,细观力学分析说明,增强体的强化作用主要来自于它对基体应力、应变状态的改变,而不是其本身对形变功的分担.

Numerical Simulation Analysis on Micro-mechanical Characteristics of Titanium Particle Reinfored Magnesium Matrix Composites

The micro-mechanical characteristics of a particulate reinforced magnesium matrix composite was analyzed by FEM simulation. The results showed that such mechanical parameters as Mises equivalent stress, stress spherical tensor, deformation- energy consumption, maximum principal stress and maximum principal strain concentrated markedly in some local areas. The stress concentration might cause local yielding although the loaded force was smaller than the matrix yielding strength. Local in- terface debonding and matrix cracking are main failure modes in the composite. Moreover, micro-mechanics analysis revealed that the strengthening effect of particulate reinforcements comes mainly from its effect on the stress and strain distribution in matrix, and secondarily from its consumption of the deformation work.