颗粒增强复合材料的动态压缩力学性能研究

首先采用Instron2300材料试验机和Hopk inson压杆冲击试验测试了10%(vo l)S iC/A l陶瓷颗粒增强金属基复合材料在不同应变率范围的应力应变曲线.结果表明,该复合材料存在明显的应变率强化效应,随应变率的增加,其流动应力也迅速增加.在不相同的应变率下,随应变的增加,复合材料的流动应力与准静态流动应力的比值趋于一常数,表明复合材料在不同的应变率下具有相同的应变硬化规律.最后用R am berg-O sgood材料模型结合应变率强化模型拟合了复合材料的动态应力应变曲线,得到了与实验结果相吻合的结果.

Dynamic Compressive Response of Particulate Reinforced Composites

The stress-strain curves of SiC particle(10% Vol.) reinforced pure Al composites were tested at different strain rates by using Instron 2300 Material Testing System and Split Hopkinson Pressure Bar.The results show that the composite is strain rate dependent material.The flow stresses of the composite were increased with the increasing of the overall strain rates.For different overall strain rates,the ratio of the dynamic flow stress to the quasi-static stress at the same strain is a constant for the larger strain(>5%),which indicates the strain hardening of the composite keeps invariable at different strain rates.The Ramberg-Osgood constitutive model,coupled with power-low strain rate hardening was used to simulate the dynamic stress strain curves at different strain rates.The prediction of the Ramberg-Osgood constitutive model agrees well with the experimental results.