水泥基压电复合材料的模拟与优化设计

发布时间：2018-06-30 04:23

本文选题：水泥基 + 压电复合材料　；参考：《浙江大学》2014年博士论文

【摘要】：水泥基压电复合材料是将压电陶瓷(PZT)按照不同的分布形式和陶瓷体积分数分布于水泥石基体中而制备成的新型材料。由于水泥基压电复合材料因压电陶瓷可以被极化而具有压电效应,使得水泥基压电复合材料在既克服传统纯陶瓷材料与混凝土相容性差等缺点的同时,又保持压电材料的优点,从而可以用于混凝土结构的健康监测中。研究水泥基压电复合材料的有效性能,对水泥基压电复合材料基于性能需求的设计、优化,以及水泥基压电传感器在实际工程中的应用具有十分重要的意义。本文重点研究不同类型的水泥基压电复合材料的性能预测理论模型,通过试验验证模型的合理性,并进行模型的数值讨论与分析,最后提出设计优化的建议。主要研究内容如下： (1)根据水泥材料作为基体容易出现与PZT夹杂粘结界面不牢固的事实,提出了合理的压电材料的广义弹簧界面模型,推导了广义弹簧模型参数与压电材料界面层(相)的的数学关系。基于夹杂的广义本征应变问题,建立了细观力学中压电材料的修正广义Eshelby张量,定量给出了修正广义Eshelby张量与经典压电材料广义Eshelby张量的关系。提出了两种修正的广义Eshelby张量的具体数值算法,并对影响修正广义Eshelby张量的界面参数进行了讨论。 (2)基于压电材料的修正的广义Eshelby张量,建立了夹杂与基体为非完美界面时的三维细观力学框架,给出修正的稀疏法、修正的Mori-Tanaka法、修正的微分法以及修正的自洽法模型的统一表达式,提出采用修正的细观力学模型预测PZT与基体为非完美界面时的压电复合材料的有效性能。通过理论预测值与文献中试验值的对比分析,初步界定了经典细观力学方法的适用范围。 (3)根据以往0-3型水泥基压电复合材料有效性能试验中出现的PZT颗粒粒径效应及PZT夹杂与水泥基体的扫描电镜结果,建立了PZT与水泥基体为非完美界面时,基于PZT颗粒平均半径的0-3型水泥基压电复合材料有效性能理论预测模型；与试验进行比较,验证了模型的可靠性；从原理上阐释了0-3型水泥基压电复合材料的有效性能产生PZT粒径效应的机制,在于水泥基体与PZT颗粒之间存在非完美界面,非完美界面对复合材料有效性能的影响随夹杂颗粒的体表比大小而变化；通过理论与试验的对比分析,提出了0-3型水泥基压电复合材料的优化设计建议。 (4)基于2-2型水泥基压电复合材料为单方向上的准周期性结构,采用宏细观相结合的多尺度模型,预测压电复合材料有效性能；试验研究了2-2型水泥基压电复合材料的有效性能,并与理论预测结果进行比对,验证了理论模型的可靠性。结果表明,通过调整压电功能相的体积分数可使2-2型水泥基压电复合材料的静水压电应变系数dhEff高于压电功能相的静水压电应变系数dhEff;结合理论与试验提出了2-2型水泥基压电复合材料的优化设计建议。 (5)依据1-3型水泥基压电复合材料为双方向上的准周期性结构,压电功能增强相的横截面为方形(或矩形)等特点,采用以多尺度模型为基础的“二次均匀法”预测了1-3型压电复合材料的有效性能；试验研究了1-3型水泥基压电复合材料的有效性能,并与理论预测结果进行比对,验证了模型的可靠性。结果表明,当采用合适的压电功能相的体积分数时,可使1-3型水泥基压电复合材料的静水压电应变系数dhEff达到最优；结合理论与试验提出了1-3型水泥基压电复合材料的优化设计建议。本研究基于但不局限于水泥基压电智能复合材料,可进一步拓展到更为广义的智能复合材料(如树脂基压电复合材料等),为包括水泥基压电复合材料在内的智能复合材料的设计与工程应用提供理论基础与科学依据。
[Abstract]:Cement based piezoelectric composite is a new type of material made of piezoelectric ceramics (PZT) distributed in different distribution forms and ceramic volume fraction in cement matrix. Due to the piezoelectric effect of piezoelectric ceramics, piezoelectric composite materials can not only overcome traditional pure ceramics because of the piezoelectric effect of piezoelectric ceramics. At the same time, the miscibility of the material and concrete is poor and the advantages of the piezoelectric materials are kept, which can be used in the health monitoring of the concrete structures. The effective performance of the cement based piezoelectric composites is studied, the design of the cement based piezoelectric composite based on the performance requirements, the optimization, and the cement based piezoelectric sensors in the actual engineering. The application is of great significance. This paper focuses on the theoretical model of the performance prediction of different types of cement based piezoelectric composites. Through the test, the rationality of the model is verified, and the numerical discussion and analysis of the model are carried out. Finally, the suggestion of design optimization is put forward. The main research contents are as follows:
(1) according to the fact that the cement material is easy to appear with the bonding interface with PZT, the generalized spring interface model of the piezoelectric material is put forward, and the mathematical relation between the generalized spring model parameters and the interface layer of the piezoelectric material is deduced. Based on the generalized eigenstrain problem of the inclusion, the meso mechanical medium pressure electricity is established. The modified generalized Eshelby tensor of the material is given. The relationship between the modified generalized Eshelby tensor and the generalized Eshelby tensor of the classical piezoelectric material is given. Two modified generalized Eshelby tensor numerical algorithms are proposed, and the interface parameters affecting the modified generalized Eshelby tensor are discussed.
(2) based on the modified generalized Eshelby tensor of the piezoelectric material, a three-dimensional meso mechanical framework is established for the imperfect interface between the inclusion and the matrix, and the revised sparse method, the modified Mori-Tanaka method, the modified differential method and the revised self consistent model are given, and the modified meso mechanical model is proposed to predict the PZT and the matrix. The application range of the classical meso mechanical method is preliminarily defined by the comparison and analysis of the theoretical predicted values and the experimental values in the literature.
(3) according to the PZT particle size effect of the 0-3 cement based piezoelectric composites and the scanning electron microscope results of the cement matrix and the PZT inclusion and the cement matrix, the theoretical prediction model of the effective performance of the 0-3 cement based piezoelectric composite based on the mean radius of the PZT particles is established. The reliability of the model is verified by comparison, and the mechanism of the effective performance of the 0-3 type cement based piezoelectric composites to produce the PZT particle size effect is explained in principle, which lies in the imperfect interface between the cement matrix and the PZT particles. The effect of the imperfect interface on the effective performance of the composite varies with the size of the inclusion particles. Based on the comparison between theory and experiment, the optimum design proposal of 0-3 type cement based piezoelectric composite material is put forward.
(4) based on the quasi periodic structure of the 2-2 cement based piezoelectric composite material in the single direction, the multi scale model combined with macro meso phase is used to predict the effective performance of the piezoelectric composite. The effective performance of the 2-2 cement based piezoelectric composite is tested and compared with the theoretical prediction results, and the reliability of the theoretical model is verified. The results show that the hydrostatic strain coefficient (dhEff) of the 2-2 cement based piezoelectric composites can be higher than the hydrostatic strain coefficient dhEff of the piezoelectric functional phase by adjusting the volume fraction of the piezoelectric functional phase, and the optimal design proposal for the 2-2 cement based piezoelectric composites is proposed in combination with the theory and test.
(5) according to the quasi periodic structure of the 1-3 cement based piezoelectric composite material, the cross section of the piezoelectric function reinforced phase is square (or rectangular). The effective performance of the type 1-3 piezoelectric composite is predicted by the "two times uniform method" based on the multi-scale model, and the experimental study of the 1-3 cement based piezoelectric composite materials is conducted in the experiment. The reliability of the model is verified by comparison with the theoretical prediction results. The results show that the hydrostatic strain coefficient dhEff of the 1-3 cement based piezoelectric composite can reach the best when the volume fraction of the suitable piezoelectric function phase is used, and the 1-3 cement based piezoelectric composite material is proposed by combining theory and test. Optimize the design proposal.
Based on but not confined to cement based piezoelectric composites, this study can be further extended to a more generalized intelligent composite material (such as resin based piezoelectric composites). It provides a theoretical basis and scientific basis for the design and engineering application of intelligent composites, including cement based piezoelectric composites.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU599

【参考文献】