NONLINEAR FINITE DEFORMATION RESPONSE OF OPEN CELL POLYURETHANE SPONGE TO FLUID FILTRATION

The nonlinear finite deformation response of open cell polyurethane sponge to fluid filtration was studied, both experimentally and theoretically. The equilibrium uniaxial strain distribution along a sponge cylinder was optically measured while it was supported on its downstream surface by a rigid filter and loaded by fluid pressure of various levels. The strain along the cylinder was found to be highly nonuniform and of sigmoidal pattern-flat near both ends and steep in the middle. The theoretical investigation considers the fluid-filled sponge as an incompressible solid-fluid mixture. The response of the sponge to uniaxial filtration was analyzed in terms of its constitutive properties which were determined experimentally. The model’s predictions show good agreement to the measured strain distribution. © 1990 by ASME.