Full-field characterization of mechanical behavior of polyurethane foams

Abstract

The foam material of interest in this investigation is a rigid closed-cell polyurethane foam PMDI with a nominal density of 20 pcf (320 kg/m 3 ). Three separate types of compression experiments were conducted on foam specimens. The heterogeneous deformation of foam specimens and strain concentration at the foam-steel interface were obtained using the 3-dimensional digital image correlation (3D-DIC) technique. These experiments demonstrated that the 3D-DIC technique is able to obtain accurate and full-field large deformation of foam specimens, including strain concentrations. The experiments also showed the effects of loading configurations on deformation and strain concentration in foam specimens. These DIC results provided experimental data to validate the previously developed viscoplastic foam model (VFM). In the first experiment, cubic foam specimens were compressed uniaxially up to 60%. The full-field surface displacement and strain distributions obtained using the 3D-DIC technique provided detailed information about the inhomogeneous deformation over the area of interest during compression. In the second experiment, compression tests were conducted for cubic foam specimens with a steel cylinder inclusion, which imitate the deformation of foam components in a package under crush conditions. The strain concentration at the interface between the steel cylinder and the foam specimen was studied in detail. In the third experiment, the foam specimens were loaded by a steel cylinder passing through the center of the specimens rather than from its end surface, which created a loading condition of the foam components similar to a package that has been dropped. To study the effects of confinement, the strain concentration and displacement distribution over the defined sections were compared for cases with and without a confinement fixture. Published by Elsevier Ltd.

Failure and Damage Analysis of Advanced Materials

“…The first is continuum modeling. The second approach is micro-modeling, in which the actual cellular structure is modeled (Jin et al, 2007;Chen et al, 1998;Ren and Silberschmidt, 2008;Gibson, 1985). To calibrate such a numerical model based on material behavior separate traction, compression, shear and hydrostatic tests are needed to provide the appropriate mechanical properties of the studied foam (Li et al, 2000).…”

Time-Resolved Dynamic Friction Testing of a Polyurethane Foam Against a Polymer/Clay Nano-composite Under Impact Loading

“…Therefore, the mechanical behaviors and energy absorption properties of the foams have been widely researched [1][2][3][4][5][6][7][8][9][10]. In fact, the interfacial friction between the foams and the objects also plays an important role in slight collisions, in which the foams would not go through large deformation.…”

In situ mechanical characterization during deformation of PVC polymeric foams using ultrasonics and digital image correlation

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