Material damping in 6061-T6511 aluminium to assess fatigue damage

• Published in: Fatigue & fracture of engineering materials & structures 2003-01, Vol.26 (1), p.79-84
• Main Authors: COLAKOGLU, M., JERINA, K. L.
• Format: Article
• Language: English
• Subjects: aluminium; Applied sciences; Condensed matter: structure, mechanical and thermal properties; damping; Exact sciences and technology; fatigue damage; Fatigue, brittleness, fracture, and cracks; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Metals. Metallurgy; Physics; vibration
• ISSN: 8756-758X; 1460-2695
• DOI: 10.1046/j.1460-2695.2003.00603.x

ABSTRACT Studies in fatigue can be summarized into two stages, fatigue crack initiation and crack propagation. Fatigue damage may increase the risk of failure under cyclic load. Energy dissipation, termed damping, occurs in engineering metals and is a function of the cyclic loading history. Damping behaviour of materials has been estimated using many different experimental techniques, and parameters i.e. the loss factor vs. strain amplitude, frequency range, etc. However, micro‐structural changes in the form of fatigue damage are also contributors to damping in engineering materials. In order to measure energy dissipation, a damping monitoring method has been used. Under a constant cyclic load up to the point of fatigue crack initiation, the effects of fatigue on damping factor were studied for 6061‐T6511 aluminium alloy. In the experiments, the stress levels were below yield point, 50% and 70% of ultimate strength. Experimental results showed that the damping factor changes with the number of fatigue cycles. Percentage increase in damping energy was calculated using experimental data.