In this paper, the response and failure of dented circular tubes with different dent depths under cyclic bending were investigated. The material used was 6061-T6 aluminum alloy and the dent depths considered included: 0.0, 0.3, 0.6, 0.9 and 1.2 mm. From the experimental moment-curvature relationship, the curve becomes symmetrical and steady loop for tubes without a dent. Due to the contact of the two sides for different dent depths, the curves show different degrees of unsymmetry but steady loops for dented tubes. Next, from the experimental ovalization-curvature curve, the ovalization of the tube cross-section increases in a symmetrical and ratcheting manner for tubes without a dent. However, due to the contact of the two sides for different dent depths, the ovalizations show different degrees of unsymmetrical, ratcheting and increasing manner for dented tubes. A higher dent depth leads to a more unsymmetrical ovalization-curvature curve. The tube buckles or fractures when the ovalization of the tube cross-section reaches a critical amount. In addition, it is shown from the experimental controlled curvature-number of cycles required to failure relationship in a log-log scale that five nonparallel straight lines correspond to five different dent depths. Finally, a theoretical formulation was proposed in this paper to simulate the relationship between the controlled curvature and the number of cycles required to failure. By comparing the theoretical analysis with the experimental data, it is shown that the theoretical formulation can properly simulate the experimental results.
|Number of pages||9|
|Journal||Chung Cheng Ling Hsueh Pao/Journal of Chung Cheng Institute of Technology|
|Publication status||Published - 2016 Nov|
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)