本文主要是實驗研究900多餘圓孔方向下改變不同多餘圓孔直徑的6061-T6鋁合金圓孔管承受循環彎曲負載下的力學行為與破裂損壞。本實驗所考慮6061-T6鋁合金圓孔管的圓孔角度為00，圓孔直徑為6 mm，而五種不同900多餘圓孔直徑大小分別為:2、4、6、8與10 mm，至於實驗結果的力學行為有:彎矩-曲率關係與橢圓化-曲率關係，而實驗結果的破裂損壞有:控制曲率-循環至損壞圈數關係與臨界橢圓化-曲率關係，其中多餘圓孔直徑為6 mm的資料是來自於楊善淵【26】的實驗結果。根據彎矩-曲率的關係顯示，從第一個循環迴圈起該關係會快速的形成一個穩定的迴圈，且多餘圓孔直徑大小對於曲線的影響非常微小。從橢圓化-曲率的關係顯示，多餘圓孔直徑越大時橢圓化增加的就越快。最後，本文參考了Kyriakides and Shaw【3】所提出的經驗公式，進而提出控制曲率-循環至損壞圈數及臨界橢圓化-曲率的理論分析模式。經過與實驗結果比較後發現，理論模擬可以合理的描述實驗結果。

This experiment mainly investigates the response and failure of 6061-T6 aluminum round-hole tubes with a 90 degree redundant hole at the same cross-section and different diameters under cyclic bending. In this experiment, the degree of the round hole of the round-hole 6061-T6 aluminum round-hole tube is at 0 degree and 6 mm in diameter. Five different diameters of the redundant hole are 2, 4, 6, 8, and 10 mm. The mechanical response is the moment-curvature and ovalization-curvature relationships. The failure is the controlled curvature-number of cycles required to ignite failure and critical ovalization-controlled curvature relationships. Among five different diameters, the experiment result of 6 mm is conducted by Yang [26]. The moment-curvature relationships indicate that after the first bending cycle, the moment-curvature loop becomes steady and the influence of the diameter of the redundant round-hole on the moment-curvature curve is infinitesimal. However, the ovalization-curvature relationships show that the greater the diameter of the redundant round-hole is, the faster the ovalization increases. Finally, theoretical analysis models were respectively proposed to simulate the controlled curvature-number of cycles required to ignite failure and critical ovalization-controlled curvature relationships. After comparing with experimental result, the experimental data can be properly described by the theoretical models.

1. Korol,R.M.,1979, “Critical Buckling Strains of Round Tubes In Flexure,’’ International Journal of Mechanics and Science,Vol.21,pp. 719-730.

2. Kyriakides,S. and Shaw, P.K., 1982, “Response and Stability ofElastoplasticCircular Pipe under Combined Bending and External Pressure,” International Journal of Solids and Structures,Vol.18, No. 11,pp.957-973.

3. Shaw,P.K. and Kyriakides,S.,1987,“Inelastic Buckling of Tubes under Cyclic Bending,”ASMEJournal of Pressure Vessel Technology,Vol.109,pp.169-178.

4. Corena,E.and Kyriakides,S.,1988,“On the Collapse of Inelastic Tubes under Combined Bending and Pressure,”International Journal of Solids and Structures,Vol.24,pp.505-535.

5. Pan, W.F., Wang, T.R. and Hsu, C.M., 1998,“A Curvature-Overlization Measurement Apparatus for Circular Tubes under Cyclic Bending,”Experimental Mechanics, Vol.38,No.2,pp.99-102.

6. Pan, W.F. and Her, Y.S., 1998,“ViscoplasticCollapse of Thin-Walled Tubes under Cyclic Bending,”Journal Engineering Materials and Technology,Vol.120,No.4,pp.287-290.

7. Pan, W.F. and Fan, C.H., 1998,“An Experimental Study on the Effect of Curvature-Rate at Preloading Stage on Subsequent Creep or Relaxation of Thin-Walled Tubes under Pure Bending,”JSME International Journal, Series A,Vol.41,No.4,pp.525-531.

8. Lee, K.L., Pan, W.F. andKuo, J.N., 2001,“The Influence of the Diameter-to-Thickness Ratio on Stability of Circular Tubes under Cyclic Bending,” International Journal of Solid andStructures,Vol.38,No.14,pp.2401-2413.

9. Pan, W.F. and Lee, K.L., 2002,“The Effect of Mean Curvature on The Response and Collapse of Thin-Walled Tubes under Cyclic Bending,”JSME International Journal,Series A, Vol. 45,No.2,pp.309-318.

10. Lee, K.L. and Pan, W.F., 2002,“Pure Bending Creep of SUS304 Stainless Steel Tubes,”Steel and Composite Structures, Vol. 2, No. 6,pp.461-474.

11. 徐建民、李國龍以及潘文峰，2003，「圓管在對稱和不對稱循環彎曲負載下的力學行為之研究」，技術學刊，第十八卷，第二期，257-262頁。
12. Lee, K.L., Pan, W.F. and Hsu, C.M., 2004, “Experimental and Theoretical Evaluations of the Effect between Diameter-to-Thickness Ratio and Curvature-Rate on The Stability of Circular Tubes under Cyclic Bending,” JSME International Journal, Series A, Vol. 47,No. 2,pp.212-222.

13. 張高華、李國龍和潘文峰，2008，「圓管承受循環彎曲負載截面變形量測器之設計」，技術學刊，第二十三卷，第一期，21-28頁。

14. Chang, K.H., Hsu, C.M, Sheu, S.R and Pan, W.F, 2005, “Viscoplastic Response and Collapse of 316L Stainless Steel under Cyclic Bending, ” Steel and Composite Structures, Vol.5,No.5, pp.359-374.

15. Chang, K.H., Pan, W.F and Lee, K.L., 2008, “Mean Moment Effect on Circular Thin-Walled Tubes under Cyclic Bending,” Structural Engineering and Mechanics, Vol. 28, No. 5, pp. 495-514.

16. Chang, K.H. and Pan, W.F., 2009, “Buckling Life Estimation of Circular Tubes under Cyclic Bending,” International Journal of Solids and Structures, Vol. 46, No. 2, pp. 254-270.

17. Lee, K.L., Hung, H.Y. and Pan, W.F., 2010, “Buckling Life Estimation of Circular Tubes of Different Materials under Cyclic Bending of Each Cross-Section of Circular Tube under Cyclic Bending,” Journal of Chinese Institute Engineers, Vol. 33, No. 2, pp. 177-189.

18. Lee, K.L., Hung, C.Y. and Pan, W.F., 2010, “Variation of Overlization for Sharp-Notched Circular Tubes under Cyclic Bending,” Journal of Mechanics, Vol. 26, No. 3, pp. 403-411.

19. Lee, K.L., Hung, C.Y. and Pan, W.F, 2011, “CCD Digital Camera System for Measuring Curvature and Overlization of Each Cross-Section of Circular Tube under Cyclic Bending,” Journal of Chinese Institute Engineers, Vol. 34, No. 1, pp. 75-86.

20. Lee, K.L., Hsu, C.M. and Pan, W.F, 2012, “The Influence of Diameter-to-Thickness Ratios on The Response and Collapse of Sharp-Notched Circular Tubes under Cyclic Bending,” Journal of Mechanics, Vol. 28, No. 3, pp. 461-468.

21. 李國龍、洪兆宇和潘文峰，2012，「循環彎曲負載下橢圓形凹槽圓管的皺曲損壞之實驗分析」，中正嶺學報，第四十一卷，第二期，183-190。

22. Lee, K.L., Hsu, C.M and Pan, W.F., 2013, “The Influence of Mean Curvatures on The Collapse of Sharp-Notched Circular Tubes under Cyclic Bending,” Journal of Chinese Society of Mechanical Engineering, Vol. 34, No. 5, pp. 461-468.

23. Lee, K.L., Hsu, C.M. and Pan, W.F., 2013, “Viscoplastic Collapse of Sharp-Notched Circular Tubes under Cyclic Bending,” Acta Mechanics SolidaSinica, Vol. 26, No. 6, pp. 629-641.

24. 潘文峰，2014，「不同方向局部尖銳凹槽圓管承受循環彎曲負載下行為影響的研究實驗」，九十周年校慶基礎學術研討會會議論文。

25. 邱易賦，2018，「圓孔管件在循環彎曲負載下之力學行為的研究」，國立成功大學工程科學研究所碩士論文。

26. 楊善淵，2019，「圓孔管件在不同角度之循環彎曲負載下之力學行為的研究」，國立成功大學工程科學研究所碩士論文。