Mechanical behavior and buckling failure of sharp-notched circular tubes under cyclic bending

다국어 초록 (Multilingual Abstract)

In this paper, an experimental investigation of the mechanical behavior and buckling failure of sharp-notched circular tubes subjected to cyclic bending is discussed. The unnotched and sharp-notched circular tubes of SUS 304 stainless steel were tested under symmetric curvature-controlled cyclic bending. It was found from moment-curvature curves that the loops show cyclic hardening and gradually steady after a few cycles for all tested tubes. The ovalization-curvature curves show an unsymmetric, ratcheting and increasing manner with the number of cycles. In addition, it was found that six almost parallel lines corresponding to unnotched and five different notch-depth (0.2, 0.4, 0.6, 0.8 and 1.0 mm) tubes were noted from the experimental relationship between the cyclic controlled curvature and the number of cycles necessary to produce buckling on a log-log scale. An empirical formulation was proposed so that it could be used for simulating the aforementioned relationship. By comparing with the experimental finding, the simulation was in good agreement with the experimental data.

참고문헌 (Reference)

1 Pan, W.F, "Viscoplastic collapse of thin-walled tubes under cyclic bending" 120 : 287-290, 1998

2 Lee, K.L, "The influence of the diameter-to-thickness ratio on the stability of circular tubes under cyclic bending" 38 : 2401-2413, 2001

3 Jiao, H, "Section slenderness limits of very high strength circular steel tubes in bending" 42 : 1257-1271, 2004

4 Kyriakides, S, "Response and stability of elastoplastic circular pipes under combined bending and external pressure" 18 (18): 957-973, 1982

5 Elchalakani, M, "Plastic mechanism analysis of circular tubes under pure bending" 44 : 1117-1143, 2002

6 Corona, E, "On the collapse of inelastic tubes under combined bending and pressure" 24 (24): 505-535, 1988

7 Kao-Hua Chang, "Mean moment effect on circular thin-walled tubes under cyclic bending" 국제구조공학회 28 (28): 495-514, 2008

8 Kyriakides, S, "Inelastic buckling of tubes under cyclic loads" 109 : 169-178, 1987

9 Shaw, P.K, "Inelastic analysis of thin-walled tubes under cyclic bending" 21 (21): 1073-1110, 1985

10 Lee, K.L, "Experimental and theoretical evaluations of the effect between diameter-to-thickness ratio and curvature-rate on the stability of circular tubes under cyclic bending" 47 (47): 212-222, 2004

11 Vaze, S, "Degradation and collapse of square tubes under cyclic bending" 31 : 325-341, 1998

12 Elchalakani, M, "Concrete-filled circular tubes subjected to constant amplitude cyclic pure bending" 26 : 2125-2135, 2004

13 Corona, E, "Buckling of elastic-plastic square tubes under bending" 38 (38): 753-775, 1996

14 Pan, W.F, "An experimental study on the effect of curvature-rate at preloading stage on subsequent creep or relaxation of thin-walled tubes under pure bending" 41 (41): 525-531, 1998

15 Corona, E, "An experimental investigation of the degradation and buckling of circular tubes under cyclic bending and external pressure" 12 : 229-263, 1991

16 Pan, W.F, "A curvature-ovalization measurement apparatus for circular tubes under cyclic bending" 38 (38): 99-102, 1998