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研究生：	廖思閔 Liao, Ssu-Min
論文名稱：	具微觀結構之軟性高分子材料之黏彈性質 Viscoelastic Properties of Soft Polymer with Microstructures
指導教授：	王雲哲 Wang, Yun-Che
學位類別：	碩士 Master
系所名稱：	工學院 - 土木工程學系 Department of Civil Engineering
論文出版年：	2015
畢業學年度：	104
語文別：	英文
論文頁數：	95
中文關鍵詞：	Cosserat 力學、黏彈性質、泡沫材料、高分子聚合物、複合材料
外文關鍵詞：	Cosserat mechanics, Viscoelatic properties, foam, polymer, composites
相關次數：	點閱：67 下載：2
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本研究將分別探討動態實驗下，所量測的泡沫材料性質，並與具微觀結構材料之數值模擬和Cosserat材料理論，相互比較與驗證，此外探討熱彈效應對鐘擺式黏彈頻譜儀所量測之正切消散模數的影響。COMSOL數值計算顯示，2D模型在靜態外力下，改變模型的形狀大約可以使楊式模數與剪力模數差距10倍，而體積模數可達千倍。隨著角度減小，負普松現象快速的消失。隨著微觀結構角度的增加，普松比提升有收斂之趨勢。隨著材料微觀結構尺寸越來越小，彈性模數有些微增加的趨勢，符合Cosserat理論的預測，亦即試體越小，彈性模數越大。Cosserat beam 與Euler beam 以及模擬結果相比在正規化的曲率100下，沒有相當大的偏差出現。此外、由理論熱彈效應所計算之Debye peak 峰約於0.01於低頻段1 10 Hz，而矽膠與橡膠所量測低頻段正切消散模數約為0.03，大約差10-30%，於此峰頻率下，實驗結果皆有稍微起伏的現象。

This research studies the effects of microstructures on overall mechanical properties of materials. The pendulum-type viscoelastic spectrometer (PVS) was adopted to measure foams and other microstructured polymer. Finite element calculations of microstructured materials with COMSOL were performed, and their results are correlated with the Cosserat theory. Under the quasi-static assumptions, the calculated effective modulus of the foam may exhibit a factor of 10 difference for the Young’s and shear modulus. For the bulk modulus, the effects of microstructure may reach a three order of magnitude difference. Calculated negative Poisson’s ratio of the foam may rapidly disappear in terms of the defined microstructural angles. With the angle decreases, Poisson’s ratio of the foam reaches a plateau. Furthermore, the effective elastic constants of the foamed materials increase as their size decrease; consistent with the Cosserat theory. In addition, the thermoelastic damping measured from the PVS experiment is consistent with the theory in terms of the location of frequency, but its damping magnitude is not matched.

CHINESE ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii
ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi
LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
NOMENCLATURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1 Goals and motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 Literature review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3 Outline of this thesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Theoretical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1 Cosserat mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Torsion vibration of a circular cylinder . . . . . . . . . . . . . . . . . . . . . . 6
3 Longitudinal vibration of a circular cylinder . . . . . . . . . . . . . . . . . . . 8
4 Constitutive law of anisotropic material . . . . . . . . . . . . . . . . . . . . . 9
5 Thermoelasticity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.1 Linear equations and frequency domain formulation . . . . . . . . . . 13
5.2 Constitutive law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Experimental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
1 General experiment elaborate . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2 Description of PVS instrument . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.1 Experiment process . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.2 Generation of pure bending and torsion by Magnet and Helmholtz coil . 23
2.3 Interaction between Laser and Position sensor . . . . . . . . . . . . . . 24
2.4 Equipment of data processing and presenting . . . . . . . . . . . . . . 25
3 Sample description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
4 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.1 Mag-Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.2 Self-Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Results and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
1 Experiment data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
1.1 Aluminum foam data . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
1.2 Polymer foam data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
1.3 Silicone gel data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
1.4 Silicone rubber data . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
1.5 Rubber data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
1.6 Thermoelastic damping . . . . . . . . . . . . . . . . . . . . . . . . . . 54
1.7 Permeability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
2 Simulation by finite element . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
2.1 2D Auxetic structure simulation . . . . . . . . . . . . . . . . . . . . . 59
2.2 2D Voronoi simulation . . . . . . . . . . . . . . . . . . . . . . . . . . 74
2.3 2D ordered hexagon structure simulation . . . . . . . . . . . . . . . . 75
Conclusions and Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
1 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
2 Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
APPENDICES
Appendix A: Random Vibration of Silicone Rubber RTV585 . . . . . . . . . . . . 81
Appendix B: Silicone Rubber of MTS experiment . . . . . . . . . . . . . . . . . 82
Appendix C: 3D Voronoi simulation . . . . . . . . . . . . . . . . . . . . . . . . . 83
Appendix D: Presentation slide . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
LIST OF REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
VITA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
                                    

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校內：2021-01-27公開
校外：2021-01-27公開

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