Response and Failure of Circumferential Sharp-Notched C2700 Brass Tubes under Cyclic Bending

Abstract

This paper investigates the response and failure of circumferential sharp-notched C2700 brass tubes with four different notch depths of 0.2, 0.4, 0.6, 0.8, and 1.0 mm subjected to cyclic bending. The wall thickness is 1.5 mm for all tested tubes, and cyclic bending loads are applied until buckling failure occurs. The experimental moment-curvature relationships exhibit a stable loop from the first bending cycles. An increase in the notch depth results in the decrease of the peak bending moment. The experimental relationships between ovalization and curvature demonstrate symmetry, serrations, and a growth pattern as cycles progress, regardless of the notch depth. Regarding the curvature-number of cycles required to initiate buckling relationships, it can be observed that five notch depths correspond to five parallel straight lines when plotted on double logarithmic coordinates. Finally, this study employs the theoretical formulation proposed by Lee in 2010 to describe the aforementioned relationships. The theoretical analysis is compared with experimental data, revealing a close alignment between the two approaches.