臺灣博碩士論文加值系統

橡膠支承墊應用於橋樑或建築物隔震時，常遭受不同環境之衝擊，造成橡膠材質之劣化，進而導致其隔震效果大幅降低。本研究依據不同之環境條件，包括紫外線照射、熱老化與反覆載重作用之情形，分別進行實驗加以探討。針對橡膠材質與橡膠支承墊施作靜態與動態性質量測，與經熱老化後橡膠之疲勞載重試驗，以評估各項環境衝擊對橡膠支承墊力學行為之影響。此外，橡膠支承墊於實際應用時，常因反覆載重造成疲勞破壞，本研究亦探討橡膠支承墊於反覆承壓時，疲勞破壞之形成，包含裂縫之初始位置與擴展速率與方向，根據現有理論，發展出一疲勞裂縫擴展機制。並針對橡膠支承墊承壓時之應力分布，計算其主應力分布與開裂應變能密度，再利用已建立之疲勞裂縫擴展機制，求得其裂縫擴展速率與能量釋放率之關係式，如此便可獲得橡膠之承墊反覆承壓時之疲勞壽命預測。並考慮於不同條件下，包含橡膠材質、形狀因子與最大壓應力等，以評估各項因素對橡膠支承墊疲勞壽命之影響。

Rubber bearings used as isolators in bridges and buildings are frequently subjected to various environmental attacks such as ultraviolet irradiation, thermal aging and cyclic compression. The reduction of mechanical properties of rubber bearings is expected when rubber materials are deteriorated after suffering from such environmental attacks. In the thesis, the effects of ultraviolet irradiation, thermal aging and cyclic compression on the static and dynamic properties of rubbers and rubber bearings are evaluated by conducting a series of mechanical tests. Meanwhile, the effects of thermal aging on the fatigue parameters of rubbers are also studied by measuring their fatigue lives and fatigue crack growth rates after suffering from different periods of thermal aging. On the other hand, when rubber bearings are subjected to cyclic compression, fatigue failure occurs due to the accumulation and propagation of some pre-existing cracks. Based on existing theoretical models, a failure mechanism of fatigue crack initiation and propagation is proposed. Then, the fatigue parameters of rubber bearings such as crack growth rate and fatigue life can also be derived from the proposed failure mechanism. In addition, the factors which affect the fatigue resistance of rubber bearings such as material properties, shape factor, intrinsic flaw size and maximum compressive stress are considered and investigated here. As a result of those, the fatigue lives of rubber bearings under different conditions are evaluated and discussed in the study.

Abstract I
Acknowledgement III
Table of Contents IV
List of Tables VII
List of Figures VIII
Chapter 1 Introduction 1
1.1 Literature Review 2
1.2 Scope of Thesis 7
Chapter 2 Rubbers under Ultraviolet Irradiation 11
2.1 Experimental Methods 11
2.1.1 Materials 11
2.1.2 Ultraviolet Irradiation Tests 12
2.1.3 Static Tests 12
2.1.4 Dynamic Transmissibility Tests 13
2.2 Results and Discussion 13
2.2.1 Static Properties 14
2.2.2 Dynamic Properties 15
2.3 Summary 18
Chapter 3 Rubbers Subjected to Thermal Aging 31
3.1 Experimental Methods 31
3.1.1Materials 32
3.1.2 Thermal Aging Tests 32
3.1.3 Static Tests 33
3.1.4 Cyclic Loading Tests 33
3.2 Results and Discussion 35
3.2.1 Energy to Break and Tear Strength 35
3.2.2 Fatigue Life 35
3.2.3 Fatigue Crack Growth Rate 38
3.3 Summary 39
Chapter 4 Deterioration of the Dynamic Properties of Rubber Bearings 51
4.1 Experimental Methods 51
4.1.1 Material 51
4.1.2 Cyclic Compression Tests 52
4.1.3 Thermal Aging Tests 52
4.1.4 Dynamic Tests 53
4.1.5 Ultraviolet Irradiation 54
4.2 Results and Discussion 55
4.2.1 Effect of Cyclic Compression 55
4.2.2 Effect of Thermal Aging 57
4.2.3 Effect of Ultraviolet Irradiation 58
4.3 Summary 59
Chapter 5 Crack Initiation and Propagation in Rubber Bearings 78
5.1 Theoretical analysis 78
5.2 Finite Element Analysis 83
5.3 Results and Discussion 85
5.4 Summary 88
Chapter 6 Fatigue Life Prediction of Rubber Bearings 107
6.1 Theoretical analysis 107
6.2 Results and Discussion 111
6.2.1 Effect of Rubber Compound 112
6.2.2 Effect of Thermal Aging 113
6.2.3 Effect of Intrinsic Flaw Size 114
6.2.4 Effect of Compressive Stress 114
6.3 Summary 115
Chapter 7 Conclusions and Suggestions 143
7.1 Conclusions 143
7.2 Suggestions 146
Reference 148

1.Bousquet, J. and Fouassier, A. J. P., “Mechanism of photo-oxidation of an elastomer.” Polymer Degradation and Stability, 5: 113-133, (1983).
2.Guzzo, M. and DePaoli., M. A., “The photo-oxidation of EPDM rubbers: part V- mechanical properties degradation of vulcanized filled samples.” Polymer Degradation and Stability, 38: 41-45, (1991).
3.Delor-Jestin, F., Lacoste, J., Barrois-Oudin, N., Cardinet and Lemaire, C. J., “Photo-, thermal and natural ageing of ethylene-propylene-diene monomer (EPDM) rubber used in automotive applications. Influence of carbon black, crosslinking and stabilizing agents.” Polymer Degradation and Stability, 67: 469-477, (2000).
4.Baba, M., Gardette, J. L. and Lacoste, J., “Crosslinking on ageing of elastomers: I. Photoageing of EPDM monitored by gel, swelling and DSC measurements.” Polymer Degradation and Stability, 63: 121-126, (1999).
5.Kumar, A., Commereuc, S. and Verney, V., “Depth-dependence of cross-linking on photo-oxidation of polyoctenamer.” Polymer Degradation and Stability, 81: 333-339, (2003).
6.Tabankia, M. H. and Philippart, J. L., “Photo-oxidation of block copoly(ether-ester) thermoplastic elastomers.” Polymer Degradation and Stability, 12: 349-362, (1985).
7.Soto-Oviedo, M. A. and De-paoli, M. A., “Photo-oxidative degradation of poly(epichlorohydrin-co-ethylene oxide) elastomer at 254 nm.” Polymer Degradation and Stability, 76: 219-225, (2002).
8.Bhowmick, A. K., Heslop, J. and White, J. R., “Effect of stabilizers in photodegradation of thermoplastic elastomeric rubber-polyethylene blends-a preliminary study.” Polymer Degradation and Stability, 74: 513-521, (2001).
9.Choi, S. S., “Influence of rubber composition on change of crosslink density of rubber vulcanizates with EV cure system by thermal aging.” Journal of Applied Polymer Science, 75: 1378-1384, (2000).
10.Layer, R. W., “Recuring vulcanizates. I. A novel way to study the mechanism of vulcanization.” Rubber Chemistry and Technology, 65: 211-222, (1996).
11.Abdel-Aziz, M. M. and Basfar, A. A., “Aging of ethylene-propylene diene rubber (EPDM) vulcanized by g-radiation.” Polymer Testing, 19: 591-602, (2000).
12.Hamza, S.S., “Effect of aging and carbon black on the mechanical properties of EPDM rubber.” Polymer Testing, 17: 131-137, (1998).
13.Ha-Anh, T. and Vu-Khanh, T., “Prediction of mechanical properties of polychloroprene during thermo-oxidative aging.” Polymer Testing, 24: 775-780, (2005).
14.Fitzgerald, J. J., Martellock, A. C., Nielsen, P. L. and Schillace, R.V., “The effect of cyclic stress on the physical properties of a poly(dimethylsiloxane) elastomer.” Polymer Engineering and Science, 32: 1350-1357, (1992).
15.Dizon, E. S., Hicks, A. E. and Chirico V. E., “The effect of carbon black parameters on the fatigue life of filled rubber compounds.” Rubber Chemistry and Technology, 47: 231-249, (1974).
16.Hamed, G. R., “Effect of Crosslink Density on the Critical Flaw Size of a Simple Elastomer.” Rubber Chemistry and Technology, 56: 244-251, (1983).
17.Fielding-Russell, G. S. and Rongone, R. L., “Fatiguing of rubber-rubber interfaces.” Rubber Chemistry and Technology, 56: 838-844, (1983).
18.Riviln, R. S. and Thomas, A. G., “Rupture of rubber. I. characteristic energy for tearing.” Journal of Polymer Science, 10: 291-318, (1953).
19.Lindley, P. B., “Energy for crack growth in model rubber components.” Journal of Strain Analysis, 7: 132-140, (1972).
20.Lake, G. J. and Lindley, P. B., “Mechanical fatigue limit for rubber.” Rubber Chemistry and Technology, 39: 348-364, (1966).
21.Lake, G. J. and Lindley, P. B., “Fatigue of rubber at low strains.” Journal of Applied Polymer Science,10: 343-351, (1966).
22.Lake, G. J. “Fatigue and fracture of elastomers.” Rubber Chemistry and Technology, 68: 435-460, (1995).
23.Mars, W. V. and Fatemi, A., “A literature survey on fatigue analysis approaches for rubber.” International Journal of Fatigue, 24: 949-961, (2002).
24.Choi. I. S. and Roland, C. M., “Intrinsic defects and the failure properties of cis-1,4-ployisoprenes.” Rubber Chemistry and Technology, 69: 591-,599 (1996).
25.Gent, A. N., Engineering with Rubber, How to Design Rubber Components, Oxford University Press, New York (1992).
26.Kelly, J. M., Earthquake-Resistant Design with Rubber, Springer-Verlag, London (1997).
27.Naeim, F. and Kelly, J. M., Design of Seismic Isolated Structures, from Theory to Practice, John Wiley & Sons (1999).
28.Lindley, P.B. and Stevenson, A., “Fatigue resistance of nature rubber in compression.” Rubber Chemistry and Technology, 55: 337-351, (1982).
29.Leicht, D. C., Yeoh, O.H., Gent, A. N., Padovan, J. and Mullen, R.L., “Adhesion failure in bonded rubber cylinders part1: internal penny-shaped cracks.” Rubber Chemistry and Technology, 76: 160-173, (2003).
30.Leicht, D. C., Rimnac. C. and Mullen, R.L., “Adhesion failure in bonded rubber cylinders part2: fatigue life prediction of external ring-shaped cracks using tearing energy approach.” Rubber Chemistry and Technology, 76: 365-385, (2003).
31.Mars, W. V., “Multiaxial fatigue crack initiation in rubber.” Tire Science and Technology, 29: 171- 185, (2001).
32.Mars, W. V., “Cracking energy density as a predictor of fatigue life under multiaxial conditions.” Rubber Chemistry and Technology, 75: 1-17, (2002).
33.Mars, W. V. and Fatemi, A., “Multiaxial stress effects on fatigue behavior of filled natural rubber.” International Journal of Fatigue, 28: 521-529, (2006).
34.Saintier, N., Cailletaud, G.. and Piques, R., “Crack initiation and propagation under mulitaxial fatigue in a natural rubber.” International Journal of Fatigue, 28: 61-72, (2006).
35.Saintier, N., Cailletaud, G. and Piques, R., “Multiaxial fatigue life prediction for a natural rubber.” International Journal of Fatigue, 28: 530-539, (2006).
36.ASTM D412 “Standard test methods for rubber properties in tension”.
37.ASTM G23 “Operating light-exposure apparatus (carbon-arc type) with and without water for exposure of nonmetallic materials.”
38.ASTM D750 “Rubber deterioration in carbon-arc or weathering apparatus.”
39.ASTM D573 “Standard test method for rubber – deterioration in an air oven”.
40.ASTM D624 “Standard test method for rubber property – tear resistance”.
41.Lake, G. J. and Lindley, P. B. “Cut crowth and fatigue of rubbers. II. Experiments on a noncrystallizing rubber.” Journal of Applied Polymer Science, 8: 707-721, (1964).
42.Horton, J. M., Tupholme, G. E. and Gover, M. J. C. “Axial loading of bonded rubber blocks.” Journal of Applied Mechanics, 69: 836-843, (2002).
43.Kelly, J. M. and Quiroz, E., “Mechanical Characteristics of Neoprene Isolation Bearings”, Report No. UBC/EERC-92/11, Earthquake Engineering Research Center, University of California Berkeley, (1992).
44.Mott, P. H. and Roland, C. M. “Uniaxial deformation of rubber cylinders.” Rubber Chemistry and Technology, 68, 739-745, (1995).
45.Lake, G. J. and Lindley, P. B., “Role of ozone in dynamic cut growth of rubber.” Journal of Applied Polymer Science, 9: 2031-2045, (1965).