中文摘要：

为研究脆性材料冲击损伤性能，对孔隙尺寸μm量级、孔隙率47％～50％的Al2O3微孔陶瓷进行了较系统的实验研究。通过对其进行应变率范围为25．4～494s^-1的冲击实验，结果表明：在较低加载率情况下，材料的模量和强度均表现出较明显的应变率敏感效应；随着加载速率的增加，强度和模量的应变率效应规律相反；而到更高的加载速率时，材料表现出应变率不敏感。借助试件表面的应变花，并与双波法实验结果进行对比，初步探讨了脆性材料在多次冲击下的累积损伤。

英文摘要：

In order to study dynamic damage characteristics of brittle materials, systematical experiments were carried out to investigate the impact behaviors of Al2O3 ceramics with 47%-50% porosity and μm scale void. In experiment the strain rate was ranging from 25.4s^-1 to 494s^-1. Results show that under lower strain rates （i. e. , from 25s^-1 to 60s^-1）, the material is rate-sensitive, both modulus and the strength increase with the loading rate increasing; while under the moderate strain rate, the modulus decrease with the loading rate increasing, but the strength increases slightly with the loading rate increasing; and under higher rates, the material appears rate-insensitive. Accumulated damage of brittle materials under repeated impact loadings is preliminarily discussed based on comparison of measured results from gauges attached to specimen surface with the calculated results based on ＂double-wave method＂.