On the study of fluid flow in a soft porous media using a scaled-up indenter

Soft porous materials are ubiquitous in the nature. Issues inherent in the response of these materials to external impacts raise problems that are broadly important in diverse areas of science and increasingly attract attentions in technology. In this paper, we report a comprehensive, experimental and theoretical approach to examine the transient fluid pressure distribution inside soft porous media when a spherical loading surface impacts on it. A novel experimental setup was developed that includes a fully instrumented hemi-spherical piston with supporting structures, and a soft porous layer underneath. Extensive experimental studies were performed in which the motion of the loading surface and the resulting transient pressure distribution were recorded. The results were compared with a novel theoretical model, leading to excellent agreements. The study significantly improves our understanding of the dynamic response of soft porous material to external compression. Especially it provides a scaled-up model to simulate the process of probe indentation, which, however, does not provide any information about the transient pore pressure distribution under the loading surface.