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PUBLICATIONS

Viscoelastic Assessment Method of Polymeric Foams under Cyclic Fatigue

Published

Author(s)

Moira M Foster, Daniel C Morrison, Alexander Landauer, Mark Herynk, Leslie Lamberson

Abstract

Many energy absorption applications utilize flexible polymeric foams for their viscoelastic properties. It is desired that the material will perform consistently across repeated compression cycles. This study examines the effect of fatigue at low strain rates on the viscoelasticity of open-cell polyurethane foam. Six polyurethanes of the same base composition with two porosities (70 % and 80 %) and three chemical indexes (79i, 100i, and 121i) are tested. Large deformation cyclic compression of the foams is conducted on a universal testing system (UTS). These data are then post-processed leveraging dynamic mechanical analysis Fourier transform rheology to characterize changes in the viscoelasticity of the materials over fatigue cycles. Results show that foams can increase or decrease in stiffness up to 10 % over 10^4 cycles. Specifically, higher chemical index, higher excitation frequency, and larger excitation amplitude correlate with a more pronounced decrease in stiffness. Damping can also change by 15 % and correlates with chemical index and excitation frequency. Consequently, the findings suggest that internal foam structure and bulk material properties as well as applied loading parameters affect the viscoelastic fatigue response of flexible polymeric foams.
Citation
Journal of Applied Polymer Science
Pub Type
Journals

Download Paper

https://doi.org/10.1002/app.55846
Local Download

Keywords

Foams, Viscoelasticity, Fatigue, Dynamic mechanical analysis
Polymers and Mechanical properties

Citation

Foster, M. , Morrison, D. , Landauer, A. , Herynk, M. and Lamberson, L. (2024), Viscoelastic Assessment Method of Polymeric Foams under Cyclic Fatigue, Journal of Applied Polymer Science, [online], https://doi.org/10.1002/app.55846, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=957161 (Accessed December 11, 2024)

Issues

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Created June 14, 2024, Updated July 5, 2024