具非完美交界面之冪函數漸變多鐵性纖維複合材料

Power Law Graded Multiferroic Fibrous Composites with Imperfect Interface

陳柏宇(Po-Yu Chen)

指導教授 ： 郭心怡

國立交通大學/工學院/土木工程系所/碩士(2020年)

摘要

本研究探討冪函數漸變功能梯度壓電壓磁纖維複合材料具非完美交界面時的磁電耦合效應。功能梯度材料(Functionally graded material, FGM)為材料性質沿半徑或厚度方向呈現漸進變化的材料，其優點是能藉由連續漸變的特性減弱因材料不連續產生的負面影響。本研究採用的漸變模型為沿半徑方向呈冪函數 漸變， 為其漸變係數。此外，早期的研究常假定材料的交界面完美且連續，但於實務上因製備過程產生的瑕疵、交界面黏著劑等皆會形成非完美交界面。常見的有廣義曳引力不連續的強非完美交界面以及廣義勢能不連續的弱非完美交界面等，本文亦將對此二種非完美交界面問題進行分析。
本研究藉由廣義雷利法(Generalized Rayleigh’s formalism)以週期性排列條件求得等效材料性質，再以複合圓柱模型(Composite cylinder assemblages model)進行一致性比對，驗證所求得之等效材料性質的正確性。驗證後再探討非完美交界面以及漸變係數對等效磁電電壓耦合係數 的影響趨勢。
數值分析廣義雷利法求得之 與複合圓柱模型有高度的一致性。在非完美交界面對 的影響之研究中，越大的強非完美交界面係數可以提升 ，弱非完美交界面則是會削弱。在漸變參數對 的影響分析中，漸變參數僅在一個小範圍數值內具增強作用。於改變材料係數的研究中，當壓電材料的磁導率、壓磁材料的壓磁係數越高；壓電材料的彈性係數、介電常數、壓磁材料的彈性係數、介電常數、磁導率越低時， 會呈現提升的趨勢。

關鍵字

冪函數漸變功能梯度材料 ； 非完美交界面 ； 反平面剪應變與面內電磁場 ； 週期性排列 ； 等效材料性質 ； 磁電耦合效應

並列摘要

We study the magnetoelectric effect of functionally graded piezoelectric-piezomagnetic fibrous composites with imperfect interfaces. The cylinders are power law graded along the radius direction. Functionally graded composites are composites with continuously varying properties across an interface between two dissimilar materials. Its main advantage is to reduce the negative effect from discontinuity. Most of early studies assumed that the interface is perfect contact. However, factors such as cracks and interface adhesive would make it imperfect. Therefore, both spring-type and membrane-type interface imperfections are discussed in this work.
We assume that the composite is subjected to anti-plane shear deformation coupled to in-plane magnetic and electric fields. We use the generalized Rayleigh’s method and the composite cylinder assemblage model (CCA model) to calculate the potential distribution and effective properties of the composite. Based on these formulations, we analyze the effect of graded parameters, imperfect interface coefficients and material properties on the magnetoelectric effect.
Numerical results show that, for a BaTiO3 - CoFe2O4 composite, the result predicted by the generalized Rayleigh’s method and CCA model are in good agreement. The graded parameters, imperfect interface coefficients and material properties dramatically affect the magnetoelectric effect of the composite. When these parameters appropriately chosen, the magnetoelectric effect can be greatly enhanced. Furthermore, among all variables, material properties affect the magnetoelectric effect most.

並列關鍵字

Power law graded materials ； imperfect interface ； anti-plane shear deformation with in-plane electromagnetic fields ； periodic arrangement ； effective properties ； magnetoelectric coupling

參考文獻

參考文獻

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