Open AccessThe Influence of Diameter-to-thickness Ratios on the Response and Failure for Locally-dented Circular Tubes Submitted to Cyclic Bending
Author(s) -
K. L. Lee,
MinHung Weng,
Wen Chi Pan
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/744/1/012005
Subject(s) - curvature , bending , tube (container) , materials science , bending moment , loop (graph theory) , structural engineering , composite material , geometry , mathematics , engineering , combinatorics
This paper describes the cyclic bending response and failure of 6061-T6 aluminum alloy locally-dented tubes (abbreviation: 6061-T6 LDT) with different diameter-to-thickness ratios (abbreviation: D o / t ratio) of 16.5, 31.0 and 60.0. A small lateral local dent was created on the tube using a simple technique. A tube having a dent depth from very shallow to about 2.4 times the thickness of the tube wall is considered. From the first bending cycle, the moment-curvature relationship depicts a closed and stable loop. Due to small and localized dents, dent depth shows very small influence on its relationship. But, as the number of bending cycle increases, the ovalization-curvature relationship shows an increase and a ratchet-like distribution. However, the dent depth shows a dramatic effect to this relationship. Furthermore, for a certain D o / t ratio, five non-paralleled straight lines of five different dent depths were found for the controlled curvature-number of cycles required to ignite failure relationship on a log-log scale. Finally, an empirical formula was introduced to describe the aforementioned relationship. As a result, the experimental and analytical data were found to agree well.