NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
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.
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 October 10, 2025)