複合材料熱傳導性質的微觀力學模型

Micromechanics Models on the Thermal Conductivities of Composites

林煊駿(Shiuan-Jiun Lin)

指導教授 ： 余念一

元智大學/工程學院/機械工程學系/碩士(2013年)

https://doi.org/10.6838/YZU.2013.00053

摘要

在這近幾十年來，複合材料因為它的獨特性質，在材料領域方面已經成為一個熱門的議題。在本研究當中，熱傳導係數可以用艾胥比(Eshelby)和森-田中(Mori-Tanaka)的模型預測。本研究有系統地推導出二種模型對複合材料之等效熱傳導係數的解析估算。此模型包括重要的微結構參數，例如長徑比，基材與異質物的性質等，並將文獻上的實驗數據與本研究的模型預測比較，發現大部分的預測與實驗值的差異均甚可觀。

最後將介電泳原理的推導作一整理。這項技術被應用在奈米碳管的等向排列。當奈米碳管在一個高頻且不均勻的交流電場中被極化時，此時會有偶極力和偶極矩作用在奈米碳管上。此時奈米碳管會旋轉，從而在單一方向排列。

關鍵字

艾胥比 ； 森-田中 ； 熱傳導 ； 介電泳

並列摘要

In the past decades, composite materials have become a popular topic in materials industry in view of their unique properties. In the present research, the thermal conductivities of composites predicted by Eshelby and Mori-Tanaka models have been derived in a systematic manner. Important microstructural parameters, such as aspect ratio and constituent properties, are included in the present models and analytic estimates are obtained. The experimental data published in literatures are then compared with the present predictions for benchmarking. The discrepancy between experimental data and present model predictions is significant for most of the cases benchmarked.

The final part of the present work is the derivation of dielectrophoresis theory, which is applied to align carbon nanotubes in composites. When carbon nanotubes are polarized by a non-uniform electric field, a dipole force and a dipole torque are developed and exerted on carbon nanotubes. While the carbon nanotubes are polarized, they rotate in the medium and consequently are aligned.

並列關鍵字

Eshelby ； Mori-Tanaka ； Thermal conductivity ； Dielectrophoretic

參考文獻

Bryning, M.B., Milkie, D. E., Islam, M. F., Kikkawa, M. J., and Yodh, A. G. (2005), “Thermal conductivity and interfacial resistance in single-wall carbon nanotube epoxy composites,” Applied Physics letters, 87, pp. 161909-1 – 161909-3.

Chen, C. H., and Wang, Y. C. (1996), “Effective thermal conductivity of misoriented short-fiber reinforced thermoplastics,” Mechanics of Materials, 23, pp. 217-228.

Xu, D., Subramanian, A., Dong, L., Nelson, B.J. (2009), “Shaping nanoelectrodes for high-precision dielectrophoretic assembly of carbon nanotubes,” IEEE Transactions on Nanotechnology, 8, pp 449-456.

Dimaki, M., and Boggild, P., (2004), “Dielectrophoresis of carbon nanotubes using microelectrodes: A numerical study,” Nanotechnology, 15, pp. 1095–1102

Eshelby, J. D. (1957), “The determination of elastic field of an ellipsoidal inclusion and related problems,” Proceedings of the Royal Society of London, A241, pp. 376-396.