有机压电材料的多物理场耦合特性研究

发布时间：2018-04-29 17:36

本文选题：PVDF复合材料 + 力、热、电本构方程　；参考：《昆明理工大学》2017年硕士论文

【摘要】：有机压电材料又称压电聚合物,最具代表性的压电聚合物材料是聚偏氟乙烯(PVDF)(薄膜)。PVDF复合材料作为一种新型智能材料,由于它精良的压电性、热释电性、铁电性被经常用于制作压电传感器、热释电传感器的换能元件。因为以PVDF复合材料作为敏感元件的传感器通常在复杂的环境下工作,极易受到多物理场耦合效应的干扰;为进一步提升PVDF复合材料的传感性能,我们拟对其力-热-电多物理场耦合特性进行深入研究。PVDF薄膜作为典型的压电材料,其压电性已被广泛而深入地研究;PVDF复合材料还具有优良的热释电性,但是对其热释电特性的研究还很少,因此论文对其热释电特性进行了阐述和分析,推导了 PVDF复合材料的热释电方程,再结合PVDF复合材料的压电方程,推导出了 PVDF复合材料的力-热-电本构方程,并运用有限元分析方法将该本构方程转换成能进行耦合场分析的数学模型,对PVDF复合材料在力-热-电多物理场的耦合特性的研究做了较好的前期工作。其次,选择了有限元方法研究PVDF复合材料的热释电效应,对热释电效应的耦合机理进行分析,并利用ANSYS编程设计,分析PVDF复合材料在热场和电场的作用下的耦合特性;然后,在对PVDF复合材料的热释电效应的研究基础上,再结合其压电效应,对PVDF复合材料的力-热-电多物理场的耦合特性进行研究,PVDF复合材料的力热电耦合特性研究主要是基于高阶位移场和高阶温度场理论建立力-电-热耦合场的有限元动力学方程,然后用ANSYS软件对PVDF复合材料在力热电耦合场中耦合特性的求解和分析,最终得出PVDF在力热电三场的作用下的耦合特性;最后,从实验测试的角度进一步研究力场、热场、电场对于PVDF这种信息功能材料的压电性能的影响。设计了产生力-热-电三场的实验方案,并开发后端数据处理系统,并进行系统测试与数据分析。研究结果显示:PVDF复合材料具有非线性的力-热-电耦合特性,在电极化可控下的温度场中,PVDF复合材料的压电性能不会随着温度升高而发生变化,PVDF压电薄片在力场、电场一定的情况下,受到热场的影响,会发生温度漂移,经计算PVDF复合材料在力热电耦合场的作用下,发生温度偏差的范围为6.8%～7.4%。
[Abstract]:Organic piezoelectric material is also called piezoelectric polymer. The most representative piezoelectric polymer material is polyvinylidene fluoride (PVDF) (thin film. PVDF composite is a new type of intelligent material, because of its excellent piezoelectric properties, pyroelectric properties. Ferroelectric properties are often used to produce piezoelectric sensors, pyroelectric sensors for energy transfer elements. In order to improve the sensing performance of PVDF composites, the sensors with PVDF composite as sensitive components are easily disturbed by the coupling effect of multiple physical fields in complex environments. As a typical piezoelectric material, the piezoelectric properties of PVDF composite have been studied extensively and deeply. The PVDF composite has excellent pyroelectric properties. However, there are few studies on the pyroelectric properties of PVDF composites. Therefore, the pyroelectric properties of PVDF composites are described and analyzed in this paper. The pyroelectric equations of PVDF composites are derived, and the piezoelectric equations of PVDF composites are combined. The force-thermoelectric constitutive equation of PVDF composite is derived, and the constitutive equation is transformed into a mathematical model for coupled field analysis by using finite element analysis method. The study of coupling characteristics of PVDF composites in the multi-physical field was carried out in the early stage. Secondly, the finite element method is selected to study the pyroelectric effect of PVDF composites, and the coupling mechanism of the pyroelectric effect is analyzed, and the coupling characteristics of PVDF composites under the action of thermal field and electric field are analyzed by ANSYS programming. On the basis of the study of pyroelectric effect of PVDF composite, combined with its piezoelectric effect, The study on the Coupling characteristics of PVDF Composites based on the Theory of High-Order displacement Field and High-order temperature Field, it is mainly based on the theory of high-order displacement field and high-order temperature field to establish the mechanical-electric-thermal-mechanical coupling field. Finite element dynamic equation, Then, the coupling characteristics of PVDF composites in thermoelectric coupling field are solved and analyzed by ANSYS software. Finally, the coupling characteristics of PVDF under the action of three fields are obtained. Finally, the force field and thermal field are further studied from the point of view of experimental test. The effect of electric field on the piezoelectric properties of PVDF, an information functional material. The experimental scheme of generating force-thermoelectric three fields was designed, and the back-end data processing system was developed, and the system test and data analysis were carried out. The results show that: PVDF composites have nonlinear mechanical-thermoelectric coupling properties, and the piezoelectric properties of PVDF composites do not change with the increase of temperature in the temperature field controlled by polarization. When the electric field is constant, the temperature drift will occur under the influence of the thermal field. By calculating the temperature deviation of PVDF composite under the action of the thermoelectric coupling field, the range of temperature deviation is 6.8 and 7.4.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33

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