Size effect on stress–strain relation of neat polyurethane foam

Chiang, Fu‐Pen; Ding, Yi

doi:10.1016/j.compositesb.2007.02.011

Cited by 15 publications

(15 citation statements)

References 11 publications

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“…The mechanical behaviors of foams are not only dictated by the microstructure of foams (described by relative density, cell shape, cell size, etc.) [2,3], but also dictated by the properties of the cell wall material [4,5]. While the mechanical behavior of cellular metallic materials has been widely studied, researches devoted to properties of the composite foams are limited.…”

Section: Introductionmentioning

confidence: 99%

Compressive property and energy absorption characteristic of open-cell SiCp/AlSi9Mg composite foams

Luo

Liu

et al. 2010

Journal of Alloys and Compounds

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Section: Introductionmentioning

confidence: 99%

Compressive property and energy absorption characteristic of open-cell SiCp/AlSi9Mg composite foams

Luo

Liu

et al. 2010

Journal of Alloys and Compounds

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“…7 10 11 Cellulose is the most abundant biomaterial in nature and its low cost and availability has led to a large body of research directed at its application into composites in part due to its low density, high specific strength and reactive surface. [12][13][14][15][16][17] Cellulose fibers are bundles of microfibrils where the individual chains are intermolecularly held together by hydrogen bonds. 17 The microfibrils consist of crystalline domains separated by amorphous domains with length varies from 100 nm to several microns.…”

Section: Introductionmentioning

confidence: 99%

Rigid Polyurethane Foam/Cellulose Whisker Nanocomposites: Preparation, Characterization, and Properties

Li¹,

Ren²,

Ragauskas³

2011

J. Nanosci. Nanotech.

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Novel rigid polyurethane nanocomposite foams have been prepared by the polymerization of a sucrose-based polyol, a glycerol-based polyol and polymeric diphenylmethane diisocyanate in the presence of cellulose whiskers. Varying amounts of sulfuric acid hydrolyzed cellulose whiskers (0.25, 0.50, 0.75 and 1.00 wt%) prepared from a commercial fully bleached softwood kraft pulp were incorporated to investigate the effect of its dosage on the mechanical and thermal properties of polyurethane nanocomposites. Fourier transform infrared spectra of the nanocomposite foams suggested that additional hydrogen bonds were developed and crosslinking occurred between the hydroxyl groups of cellulose whiskers and isocyanate groups which increased the phase separation of soft and hard segments in the polyurethane. The closed cells of control foam and nanocomposite foams were homogeneously dispersed and the cell sizes were approximately 350 microm in diameter as observed by scanning electron microscope. A substantial improvement of mechanical properties at low whisker content (< or = 1.00 wt%) was obtained, especially the compressive strength and modulus at 1.00 wt% whiskers content which were increased by 269.7% and 210.0%, respectively. Thermal stability of the nanocomposites was also enhanced as determined by differential scanning calorimetry and thermogravimetric analysis.

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“…In-depth surfaces failure cannot be distinguished although they affect to some degree the displacement estimation [15]. Its high potential for heterogeneous materials or biomechanical applications [22], from macro level failure characterization [23][24][25], to micro scale strain field estimation [26][27][28] has motivated several investigations.…”

Section: Introductionmentioning

confidence: 99%

“…On the other hand, some works have used DIC to characterize the heterogeneous strain field in PUR foams. Chiang and Ding [27] employed a multi-speckle technique (similar to DIC technique) to observe the differences in the strain field between macro and micro-size PUR samples when submitted to tensile loading. Although the deformation was almost uniform along the largest samples, the micro-size ones revealed heterogeneous patterns.…”

Section: Introductionmentioning

confidence: 99%

Some Practical Considerations for Compression Failure Characterization of Open-Cell Polyurethane Foams Using Digital Image Correlation

Belda

Megías

Feito

et al. 2020

Sensors

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(1) Background: Open-cell polyurethane foam mechanical behavior is highly influenced by microstructure. The determination of the failure mechanisms and the characterization of the deformation modes involved at the micro scale is relevant for accurate failure modeling. (2) Methods: We use digital image correlation (DIC) to investigate strain fields of open-cell polyurethane foams of three different densities submitted to compression testing. We analyze the effect of some DIC parameters on the failure pattern definition and the equivalent strain magnification at the apparent ultimate point. Moreover, we explore speckle versus non-speckle approaches and discuss the importance of determining the pattern quality to perform the displacement correlation. (3) Results: DIC accurately characterizes the failure patterns. A variation in the subset size has a relevant effect on the strain magnification values. Step size effect magnitude depends on the subset size. The pattern matching criterion presented little influence (3.5%) on the strain magnification. (4) Conclusion: The current work provides a comprehensive analysis of the influence of some DIC parameters on compression failure characterization of foamed structures. It highlights that changes of subset and step sizes have a significant effect on the failure pattern definition and the strain magnification values, while the pattern matching criterion and the use of speckle have a minor influence on the results. Moreover, this work stands out that the determination of the pattern quality has a major importance for texture analysis. The in-depth, detailed study carried out with samples of three different apparent densities is a useful guide for DIC users as regards texture correlation and foamed structures.

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Size effect on stress–strain relation of neat polyurethane foam

Cited by 15 publications

References 11 publications

Compressive property and energy absorption characteristic of open-cell SiCp/AlSi9Mg composite foams

Compressive property and energy absorption characteristic of open-cell SiCp/AlSi9Mg composite foams

Rigid Polyurethane Foam/Cellulose Whisker Nanocomposites: Preparation, Characterization, and Properties

Some Practical Considerations for Compression Failure Characterization of Open-Cell Polyurethane Foams Using Digital Image Correlation

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