Modeling of Viscoelastic Behavior of Flexible Polyurethane Foams Under Quasi-Static and Cyclic Regimes

Purpose The efficiency of fractional derivative and hereditary combined approach in modeling viscoelastic behavior of soft foams was successfully addressed in Elfarhani et al. (2016a). Since predictions obtained on flexible polyurethane foam (FPF) type A (density 28 kg m−3) were found very promoting, the purpose of this paper is to apply the approach basing on two other types of foams. Both soft polyurethane foams type B of density 42 kg m−3 and type C of density 50 kg m−3 were subjected to multi-cycles compressive tests. Design/methodology/approach The total foam response is assumed to be the sum of a non-linear elastic component and viscoelastic component. The elastic force is modeled by a seven-order polynomial function of displacement. The hereditary approach was applied during the loading half-cycles to simulate the short memory effects while the fractional derivative approach was applied during unloading cycles to simulate the long memory effects. An identification methodology based on the separation of the measurements of each component force was developed to avoid parameter admixture problems. Findings The proposed model reveals good reliability in predicting the responses of the two considered flexible foams. Predictions as measurements establish that residual responses were negligible compared to elastic and viscoelastic damping responses. Originality/value The development of a new combined model reveals good reliability in predicting the responses of the two polyurethane foams type A and B.

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Experimental Study on the Ignition Behavior of Flexible Polyurethane Foams by a Smoldering Cigarette

Journal of Applied Fire Science ◽

10.2190/af.22.4.a ◽

2012 ◽

Vol 22 (4) ◽

pp. 375-386

Author(s):

Qiyuan Xie ◽

Hejiang Zhu

Keyword(s):

Experimental Study ◽

Polyurethane Foams ◽

Flexible Polyurethane

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Vibration damping behavior of flexible polyurethane foams under low and high strain regimes

Proceedings - Automotive Acoustics Conference 2017 ◽

10.1007/978-3-658-20251-4_16 ◽

2019 ◽

pp. 273-291

Author(s):

Mark Brennan ◽

Martino Dossi ◽

Yueqi Wang ◽

Maarten Moesen ◽

Jan Vandenbroeck

Keyword(s):

High Strain ◽

Polyurethane Foams ◽

Vibration Damping ◽

Damping Behavior ◽

Flexible Polyurethane

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Identification of Nonlinear Viscoelastic Models of Flexible Polyurethane Foam From Uniaxial Compression Data

Journal of Engineering Materials and Technology ◽

10.1115/1.4032169 ◽

2016 ◽

Vol 138 (2) ◽

Cited By ~ 5

Author(s):

Yousof Azizi ◽

Patricia Davies ◽

Anil K. Bajaj

Keyword(s):

Uniaxial Compression ◽

Viscoelastic Model ◽

Viscoelastic Behavior ◽

Model Parameters ◽

Viscoelastic Models ◽

Nonlinear Viscoelastic ◽

Compression Data ◽

Computationally Intensive ◽

Nonlinear Viscoelastic Model ◽

Flexible Polyurethane

Flexible polyethylene foam is used in many engineering applications. It exhibits nonlinear and viscoelastic behavior which makes it difficult to model. To date, several models have been developed to characterize the complex behavior of foams. These attempts include the computationally intensive microstructural models to continuum models that capture the macroscale behavior of the foam materials. In this research, a nonlinear viscoelastic model, which is an extension to previously developed models, is proposed and its ability to capture foam response in uniaxial compression is investigated. It is hypothesized that total stress can be decomposed into the sum of a nonlinear elastic component, modeled by a higher-order polynomial, and a nonlinear hereditary type viscoelastic component. System identification procedures were developed to estimate the model parameters using uniaxial cyclic compression data from experiments conducted at six different rates. The estimated model parameters for individual tests were used to develop a model with parameters that are a function of strain rates. The parameter estimation technique was modified to also develop a comprehensive model which captures the uniaxial behavior of all six tests. The performance of this model was compared to that of other nonlinear viscoelastic models.

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Water-blown rigid and flexible polyurethane foams containing epoxidized soybean oil triglycerides

Journal of Applied Polymer Science ◽

10.1002/app.28153 ◽

2008 ◽

Vol 109 (1) ◽

pp. 537-544 ◽

Cited By ~ 36

Author(s):

Yuan-Chan Tu ◽

Galen J. Suppes ◽

Fu-Hung Hsieh

Keyword(s):

Soybean Oil ◽

Polyurethane Foams ◽

Epoxidized Soybean Oil ◽

Flexible Polyurethane

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In situ monitoring of isophorone diisocyanate-based flexible polyurethane foams formation

Journal of Cellular Plastics ◽

10.1177/0021955x16670579 ◽

2016 ◽

Vol 54 (1) ◽

pp. 37-52 ◽

Cited By ~ 3

Author(s):

I Eceiza ◽

L Irusta ◽

A Barrio ◽

MJ Fernández-Berridi

Keyword(s):

Foam Height ◽

Polyurethane Foams ◽

In Situ Monitoring ◽

Generation Process ◽

Isophorone Diisocyanate ◽

Experimental Conditions ◽

Foaming Process ◽

Foam Generation ◽

Flexible Polyurethane

Novel isophorone diisocyanate-based flexible polyurethane foams were prepared by the one-step method in a computerized foam qualification system (FOAMAT). The experimental conditions to obtain this type of foams, in relation to the nature and concentration of catalysts as well as the reaction temperature, were established as no data were available in scientific literature. The chemical reactions occurring during the foam generation process were monitored in situ by attenuated total reflectance-FTIR spectroscopy. The kinetics of the foam generation was fitted to an nth order model and the data showed that the foaming process adjusted to a first-order kinetics. The physical changes as pressure, foam height, and dielectric polarization were monitored by the FOAM software (FOAMAT). According to these parameters, the foaming process was divided into four steps: bubble growth, bubble packing, cell opening, and final curing.

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