Squeeze process under impact, in highly compressible porous layers, imbibed with liquids

The paper proposes a model for the squeeze process under impact for highly compressible porous layers imbibed with fluids (HCPL). It is assumed that the normal forces generated by elastic compression of the fibers comprising the solid phase are negligible compared to the pressure forces generated in the imbibed fluid, within the porous layer. The process, named ex-poro-hydrodynamic (XPHD) lubrication, is strongly dependent on porosity variation and consequently on permeability variation. Closed form analytical solutions are given for circular and rectangular contacts with various boundary conditions. Numerical applications show the existence of optimum initial compacticity, sigma(0), that minimizes the maximum impact force (i.e. the maximum damping effect). These interesting results can be useful for the design of squeeze dampers and shock absorbers based on XPHD lubrication. (C) 2009 Elsevier Ltd. All rights reserved.