Bioinspired Dampers: Meniscus-Inspired Energy Dissipation Components

Abstract

Nature provides examples of functionally graded porous structures that effectively absorb energy, such as the knee meniscus. The meniscus features a three-layered structure with varying porosity from the outer to inner layers. The tissue’s porous spaces are fluid-saturated, facilitating energy dissipation and damping. Inspired by this architecture, we designed two 3-layered porous geometries. These geometries consist of thin outer layers and a thicker inner layer with higher porosity and permeability. They were created using image analysis, computational fluid dynamics (CFD) simulations, and pore space segmentation (PSS). The PSS geometry shows a reduced peak pore diameter (88 μ m vs. 111 μ m) and an increased density of lower throat lengths but a slightly larger throat radius compared to the CFD geometry. These differences significantly impact permeability, with PSS samples showing a peak of 1522 D versus 151 D in CFD samples. We compared their energy dissipation capabilities through cyclic compression experiments at varying rates and with different fluid viscosities. The dissipation energy density of the CFD geometry (1.8 KPa) was 2.5 times higher than that of the PSS geometry (0.7 KPa). Scanning Electron Microscopy (SEM) compression tests revealed deformation patterns, including crease formation, bulging, and permanent deformation.

Keywords: Energy dissipation, Bio-inspired dampers, cyclic compression tests, porous materials