The high strain tensile deformation of open-cellfoams is analyzed, using a Kelvin foam lattice model. Thestretching, bending, and twisting of elastic cell edges is analyzed,and the deformed cell shapes predicted. The stress-strain relationand Poisson's ratio are predicted for strains up to 40, for tensionin the 100 and 111 directions of the BCC lattice. The latterprediction is closest to stress-strain curves for polyurethane foams,especially when the cell shape anisptropy is taken into account. Thechange from edge bending to extension as the main deformationmechanisms, for strains exceeding 20, increases the sloped of thestress-strain curve. A comparison is made with irregular cell structure models.
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