含脫膠區奈米複材三明治結構之振動行為研究

Vibration Behavior of Sandwich Structure with Face/Core Debonding and MWNTs/Polymer Nanocomposites Core

蔡尚南(Shang-Nan Tsai)

指導教授 ： 葉孟考

國立清華大學/工學院/動力機械工程學系/碩士(2012年)

摘要

三明治結構是一種常用的複合材料，由於其具有高比勁度、高比強度以及質量輕等優點，近年來已被大量地使用，特別是在航空、汽車、造船、國防工業方面。三明治結構的芯材多半是選擇質量輕的材料（發泡性高分子材料或者是蜂巢狀結構）；而面材通常是高強度以及高勁度的材料，例如纖維複合材料(碳纖維、玻璃纖維)或是金屬材料。本文所使用的三明治結構其芯材由環氧樹脂添加奈米碳管組成，而面材則為碳纖維疊層板的複合材料，並利用環氧樹脂做為面材和芯材的黏著劑。
本文以有限單元分析軟體ANSYS及實驗探討具有脫膠區之三明治結構之振動行為，並觀察芯材奈米碳管含量、面材碳纖維疊層板堆疊角度、以及脫膠區等三項因素對振動頻率及其模態的影響。
結果顯示芯材中添加奈米碳管會提高三明治結構的自然頻率，而不同面材堆疊方式也對自然頻率及模態有所影響；此外脫膠區越長時，自然頻率下降越多。

關鍵字

奈米複合材料 ； 奈米碳管 ； 三明治結構 ； 振動測試 ； 有限單元分析

並列摘要

Because of its’ high specific strength and high specific stiffness, sandwich structure has been widely used in many applications, especially in automotive industry, aviation, shipbuilding and national defense industries. Usually, the core material of sandwich structure is light foam material or honeycomb structure, and high strength material, like fiber composites or metal material, is chosen for the facesheet. In this paper, we use MWNTs/epoxy for the core and carbon fiber laminate for the facesheet. The facesheet and core were glued together by epoxy.
The finite element analysis software ANSYS and experiment were used to study the vibration behavior of sandwich structure with or without debonding region. The influence of MWNTs content, facesheet stacking sequence and debonding length were discussed in this paper.
The results show that with the increase of MWNTs in core, the natural frequencies of the sandwich structure increased. Different CFRP stacking sequences influenced the natural frequencies and mode shapes. Besides, with the increase of debonding length, the natural frequencies of the sandwich structure decreased more.

並列關鍵字

Nanocomposites ； Carbon Nanotube ； Sandwich Structure ； Vibration Test ； Finite Element Method

參考文獻

1. N. J. Pagano and R. B. Pipes, “The Influence of Stacking Sequence on Laminate Strength,” Journal of Composite Materials, Vol. 5, pp.50-57, 1971.

2. A. Muc, “Optimal Fiber Orientation for Simply-Supported, Angle-Ply Plate Under Biaxial Compression,” Composite Structures, Vol. 9, pp.161-172, 1988

3. J. Brillaur and A. E. Mahi, “Numerical Simulation of the Influence of Stacking Sequence on Transverse Ply Cracking in Composite,” Composite Structures, Vol. 17, pp. 23-35, 1991.

4. T. C. Truong, M. Vettori, S. Lomov and I. Verpoest, “Carbon composites based on multi-axial multi-ply stitched preforms. Part 4. Mechanical properties of composites and damage observation,” Composites: Part A, Vol. 36, pp. 1207-1221, 2005.

5. L. D. Patrick and D. Laurent, “Numerical tools for advanced composite materials: a mean to reduce costs and improve performance,” The 24th international SAMPE Europe conference, Paris, France; 2003.