Frequency dependent fatigue behaviour of additively manufactured titanium lattices
File(s)1-s2.0-S1350630723004296-main.pdf (1.87 MB)
Published version
Author(s)
Jones, Adam
Jeffers, Jonathan
Oosterbeek, Reece
Type
Journal Article
Abstract
Additively manufactured (AM) porous titanium lattices, with their ability to match the mechanical properties of bone and avoid stress shielding, are a popular candidate material for orthopaedic implants. Such implants are now emerging as treatments for conditions like osteoarthritis and fixation of bone fractures. Fatigue tests are critical due to the cyclic loading environment and must be carried out at an accelerated loading rate to simulate many years of use. Tests are typically performed with servohydraulic instruments, which limits the cyclic compression to relatively low frequencies (15 Hz). Fatigue testing at a higher frequency would accelerate research, however, may introduce phenomena such as heat accumulation and strain rate effects. In this study the fatigue behaviour of a pure titanium stochastic lattice was determined at two test frequencies, 15 Hz and 110 Hz. Testing was conducted using an electromechanical dynamic system. The fatigue strengths at 106 cycles were 5.607±0.106 MPa and 5.764±0.214 MPa at 15 Hz and 110 Hz respectively. A hypothesis t-test at a 95% confidence level stated that there was significant evidence that the population means were not the same, demonstrating evidence of a difference in fatigue strength with testing frequency. However, we can conclude that the 2.8% increase in fatigue strength due to test frequency effects is inconsequential relative to the time saved (16 hours per test) and typical batch-to-batch variability in fatigue strength of approximately 12%. The results of this study should help accelerate research into the fatigue properties of AM porous lattices.
Date Issued
2023-10
Date Acceptance
2023-07-06
Citation
Engineering Failure Analysis, 2023, 152, pp.1-7
ISSN
1350-6307
Publisher
Elsevier
Start Page
1
End Page
7
Journal / Book Title
Engineering Failure Analysis
Volume
152
Copyright Statement
© 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/4.0/).
(http://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
https://www.sciencedirect.com/science/article/pii/S1350630723004296
Publication Status
Published
Article Number
107475
Date Publish Online
2023-07-11