Self-Healing Constitutive Behaviour of Poroelastic Architected Matter: A New Regime in Smart Aerospace Structural Design

In this study, we present a mechanics-based numerical constitutive modelling approach that tunes a fundamental structural characteristic, namely the porosity, in interaction with the fluid within it. The approach, based on Biot's three-dimensional consolidation theory in conjunction with Darcy's law of fluid flow, transforms a normal poroelastic structure into a smart one. This is exemplified using a poroelastic beam, with the assumption of functional porosity varies along the longitudinal axis and that fluid flow is confined to this axis. We demonstrate a viscoelastic-like delayed deformation followed by saturation behaviour. Additionally, we show the existence of self-healing properties in such structures. Such time-dependent deformation with saturation can be utilized to control energy absorption, dampen vibrations, and handle thermal/mechanical loads over time. The self-healing property offers the potential to extend service life, reduce maintenance, and enhance resilience in applications such as aircraft interiors and joints, and impact protection. Though demonstrated using a beam, the approach has potential extensions to metalattice structures composed of similar smart porous beam elements. This could unlock a plethora of features relevant to aerospace applications, such as a high stiffness-to-weight ratio, among others.