臺灣博碩士論文加值系統

複材層疊板的結構件有很多的用途, 如用在航太工業, 汽車工業和土木工程等. 因為層疊板可以提
供一些較好的性能, 如低重量和高強度等. 在超音速飛機高速飛行時, 控制翼面和機身外殼蒙皮等會受
到很大空氣動力負載的作用, 所以我們將研究這些多層複材層疊板的層間應力之變化情形. 薄的層疊板
構件常常操作於高溫的結構體, 尤其是在加熱或泠卻之時, 熱應力及變形對於層疊板的彎曲及層間應力
值將很有影響. 對於中等厚度的複材層疊板受到熱應力的彎曲作用時, 我們須做一些包含橫向剪應變的
分析, 以瞭解橫向剪應變對複材層疊板的層間應力與變形量之影響.
我們將利用應力函數變分法[1]來做層疊板的層間應力分析, 利用GDQ數值方法[2]來做層疊板的熱
應力分析. 在層間應力分析方面, 我們將考慮一個長的自由端層疊板,受到任意的軸向伸張,彎曲之機械
力和受到空氣彈力的作用情形. 我們將分析在層疊板的上表面有一流體流過所產生的穩態和非穩態空氣
動力負載, 對於直交層和角交層的四層對稱層疊板內自由端的層間應力值有何影響. 我們也將分析受到
振動的層疊板之層間應力值. 在熱應力分析方面, 我們將考慮長方形層疊板受熱膨脹負荷及均勻壓力負
荷作用下, 產生彎曲時之層間應力值. 我們也將分析長方形層疊板受正弦溫度變化的熱應力及考慮橫向
剪應變的作用下, 產生彎曲時之層間應力值與層疊板中央位置的變形量.
在層間應力分析方面, 應力函數變分法和有限差分的數值方法已經用來計算出長的多層層疊板, 受
軸向應變和彎曲曲度之穩態、非穩態空氣動力負載情況下、振動作用情況下的層間應力值. 我們得到一
些結果: (1)應力函數變分法提供計算長的多層層疊板之層間應力值的一種方法.(2)有限差分的數值方法
在沒有穩態空氣動力負載的情況下, 所得到的層間應力結果, 與Wang 和 Crossman的數值結果[3]相接
近. (3)穩態空氣動力負載對四層層疊板內自由端的層間應力值有很大的影響, 而且隨著馬赫數的增加而
增加. (4)當受到較大自然振動頻率作用時, 其層間應力值的振動也越大.
在熱應力的GDQ數值方法分析方面, 我們得到一些結果:(1)GDQ法提供計算長方形多層層疊板受到
熱彎曲之層間應力值和變形量的一種方法. (2)受到均勻壓力的熱彎曲之八層層疊板之層間應力值和變形
量結果與Navier的數值結果相接近. (3)GDQ法對飛機引擎附近的熱彎曲之層間應力值和變形量預測有很
大的用處. (4)GDQ的數值方法在受正弦溫度變化的熱應力及考慮橫向剪應變的作用,產生彎曲時之層間
應力值與層疊板中央位置的變形量, 所得到的結果與Reddy & Hsu 的數值結果[4]相接近.

In the part of the interlaminar stresses analyses, a stress-function-based variational approach is used to determine the interlaminar stresses in a multilayered strip of laminate subject to arbitrary combinations of axial extension, bending, the steady and the unsteady aerodynamic loading of fluid flow over the upper surface of laminated composite plate. The finite difference method for determining the interlaminar stresses in a laminated strip is used. Symmetric four-layer, cross-ply and angle-ply laminates are considered in detail. Some numerical solutions by using a personal computer are obtained. The present results for four-layer laminates show that the aerodynamic loading has significant effects on the interlaminar stresses near the free-edge regions.
In the part of thermal stress analyses, a GDQ (Generalized Differential Quadrature) method is presented for the thermal bending of numerical interlaminar stress and displacement in eight-layer of orthotropic plate with unidirectional, cross-ply and angle-ply laminate under thermally expansion load and uniform transverse load. When the moderately thick of orthotropic, anisotropic, laminated plate is considered, the transverse shear deformation in thermal stress and deflection of bending analysis should be involved.

COVER
TABLE OF CONTENTS
Chapter 1 Introduction
Chapter 2 Interlaminar stress analyses
2.1 Steady-state aeroelasticity of fluid-flow over a laminated composite
2.2 Effect of vibration on the interlaminar stresses of a composite
2.3 Effect of unsteady aerodynamic pressure load on the interiaminar stresses of laminated composite plates
Chapter 3 Thermal stress analyses
3.1 Thermal bending analysis of laminated orthotropic plates by the GDQ mthod
3.2 Shear deformation in thermal bending analysis of laminated orthotropic plates by the GDQ method
3.3 Shear deformation in thermal bending analysis of laminated anisotropic plates by the GDQ method
Chapter 4 Computational results
Chapter 5 Concluding remarks
Figures and tables

[1] Yin, W.-L. (1994). Free-Edge Effects in Anisotropic Laminates Under Extension, Bending and Twisting,
Part I: A Stress-Function-Based Variational Approach. ASME Journal of Applied Mechanics 61, pp. 410-415.
[2] Shu, C. and Du, H. (1997). Implementation of Clamped and Simply Supported Boundary Conditions in the
GDQ Free Vibration Analyses of Beams and Plates. Int. J. Solds Structures Vol. 34, No. 7, pp. 819-835.
[3] Wang, A. S. D. and Crossman, F. W. (1977). Some New Results on Edge Effects in Symmetric Composite
laminates. J. Composite Materials, Vol. 11, pp. 92-106.
[4] Reddy, J. N. and Hsu, Y. S. (1980). Effects of Shear Deformation and Anisotropy on the Thermal Bending
of Layered Composite Plates. Journal of Thermal Stresses, Vol. 3, pp. 475-493.