(中南大学 粉末冶金国家重点实验室,长沙 410083)
摘 要: 利用有限元软件ANSYS模拟分析电极结构、压电陶瓷纤维厚度及体积分数等结构参数对纤维内部电场分布及复合物驱动应变性能的影响规律。结果表明:具有交叉指形电极结构的压电纤维复合物在纤维内部存在不均匀电场区域,其强度和体积分数共同制约着复合物的驱动应变性能。在恒定电场条件下,当交叉指形电极宽度为纤维厚度的一半时,复合物具有最大应变量;厚度较小的压电陶瓷纤维内部的均匀电场强度较高和体积分数较大,进而有利于提高复合物的驱动应变性能。在恒定电压条件下,电极指间距越大,复合物的驱动应变量越小。当指间距和指宽的比>10时,应变量可达到理想状态的90%。压电陶瓷纤维体积分数越高的复合物越容易获得较大的驱动应变性能。
关键字: 压电纤维复合物;有限元法;电极结构;压电陶瓷纤维
(State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China)
Abstract:The effect rules of electrode structure, piezoelectric ceramic fiber thickness and volume fraction on the electric field distribution in fiber and strain properties of composite were simulated and analyzed by finite element using ANSYS. The results show that the inhomogeneous zone exists in the fiber of piezoelectric fiber composites with interdigitated electrode. And the strain properties of composite are influenced simultaneously by the field strength and proportion of this zone. When the constant electric field is applied, the highest strain is generated when the electrode width is half of the fiber thickness. The field strength and proportion of the homogeneous zone in the thinner piezoelectric ceramic fiber are higher, which improves the strain properties of the composite. When the constant voltage is applied, the strain decreases with the increase of the electrode separation. 90% of ideal strain can be achieved with the electrode separation to the width larger than 10. The strain properties of the composite can be improved using the piezoelectric fiber with higher volume fraction.
Key words: piezoelectric fiber composites; finite element method (FEM); electrode structure; piezoelectric ceramic fiber