Speaker
Description
Multicellular aggregates represent a wide class of hydrated soft biological media, in which the interplay between the flow of the interstitial fluid and the reorganization of the internal structure (remodeling) dictate the overall mechanical and hydraulic properties of the aggregates [1].
An interesting phenomenon occurring, for instance, when indentation and torsion tests are performed on multicellular aggregates is the formation of boundary-layers nearby the points of contact between experimental apparatus and specimen [2]. There, the ductility properties and the hydraulic behavior of the aggregates can significantly deviate from the ones found in its interior, and some authors attribute these effects to local changes in the boundary curvature [3].
With the objective of capturing these boundary effects, in this presentation we adapt the strain-gradient plasticity theory by Gurtin and Anand [4] to describe the remodeling of a biphasic medium in non-Darcian regime. In doing so, we follow the main steps taken in [5], where we give particular emphasis on the thermodynamical and computational aspects of the work.
References
[1] Giverso, C., Preziosi, L., “Modelling the compression and reorganization of cell aggregates”, Math Med Biol, 29(2), 181–204 (2012).
[2] Fleck, N. A., and Hutchinson, J. W. (1997). Strain gradient plasticity. Advances in Applied Mechanics, 33, 295–361.
[3] Callens, S. J., Uyttendaele, R. J., Zajac, M., and Zadpoor, A. A. (2020). Substrate curvature as a design parameter for complex tissue structures. Biomaterials, 232, 119739.
[4] Gurtin, M. E., Anand, L., “A theory of strain-gradient plasticity for isotropic, plastically irrotational materials. Part II: Finite deformations”, Int. J. Plas., 21(12), 2297–2318 (2005).
[5] Giammarini, A., Pastore, A., Ramírez-Torres, A., and Grillo, A., “A first-gradient approach to the remodeling and fluid flow in saturated porous media”, Math. Mech. Solids, 30(9), 2185–2223 (2025).