PMN/CB/EP阻尼性能的力和频率特性

Effects of Dynamic Stress and Frequency on Damping Performance of PMN/CB/Epoxy Composites

采用动态力学热分析方法,研究了载荷应力和振动频率对铌镁锆钛酸铅(PMN)/导电炭黑(CB)/环氧树脂(EP)复合材料阻尼性能的影响。结果表明,随着动态应力的增大,复合材料的损耗因子峰值tanδmax增大,玻璃化转变温度Tg降低,而阻尼温域ΔT逐渐增加。当应力大于2000mN时,tanδmax、Tg变化的幅度较小,但ΔT有较大的增幅。动态应力对复合材料的模量有较大的影响,在T<Tg温度区,储能模量和损耗模量均随应力的增大而增大。当应力和温度不变时,对PMN/CB/EP复合材料进行了频率扫描,储能模量随频率的增大而增大,损耗模量先增大,达到最大值后逐渐衰减,tanδ在扫描频率范围内均随测试频率的增大而降低。

Dynamic stress and test frequency exert considerable influence on damping behaviour of damping composite were researched. In this research, the effects of dynamic stress and test frequency on the damping behaviour of the PMN/CB/EP composites were examined by characterization of dynamic mechanical analysis （DMA）. The results show that with the increasing of dynamic stress and the peak value of loss factor, the glass transition temperature decreases, and the damping temperature range increases. The results also describes little change of the peak value of loss factor and glass transition temperature, but a rather rising of damping temperature range when the dynamic stress loaded is more than 2 000 mN. Dynamic stress effects are found to profoundly influence the storage modulus and loss modulus of the PMN/CB/EP composite. When the dynamic stress and temperature keep constant, frequency scan carries out that the storage modulus increases with the increasing of test frequency, the loss modulus increases to a maximum then attenuates gradually, and the loss factor decreases at all testing frequency range. The fact reflected in this research is that the damping properties of PMN/CB/EP composites exhibit dependence on dy- namic stress and test frequency.