The Influence of a Redundant Hole with the Same Cross-Section and Different Directions on the Response of Round-Hole Tubes under Cyclic Bending

Abstract

This paper is mainly to study the response and failure of 6061-T6 aluminum alloy round-hole tubes with a redundant round hole on the same cross-section and five different hole directions of 45° 67 5° 90° 135° and 180° under cycling bending The diameters of the round hole and redundant hole are 6 mm The experimental data include: moment-curvature curves ovalization-curvature curves controlled curvature- number of bending cycles required to ignite failure curves and critical ovalization- controlled curvature curves The moment-curvature curve exhibits a stable loop from the first bending cycle From Experimental ovalization-curvature curves the ovalization of the tubes increases in asymmetrical and ratcheting manner From the controlled curvature-number of bending cycles required to ignite failure curves the number of bending cycles required to ignite failure is affected by different redundant hole directions From the critical ovalization-controlled curvature curves the larger controlled curvature leads the larger critical ovalization Finally theoretical formulations were proposed in this study to simulate the controlled curvature-number of bending cycles required to ignite failure and critical ovalization-controlled curvature relationships By comparing the theoretical analysis with the experimental data theoretical formulations properly simulate the experimental results

Date of Award	2019
Original language	English
Supervisor	Wen-Fung Pan (Supervisor)