Highly energy dissipative 3D-printed composite panel inspired by the lobster shells for applications on the lunar surface
Topic(s) : Special Sessions
Co-authors :
Pierre-Louis PICHARD (FRANCE), Laurent MAHEO (FRANCE), Justin DIRRENBERGER , Ugo LAFONT (NETHERLANDS), Antoine LE DUIGOU (FRANCE)Abstract :
Establishing a permanent human presence on the lunar surface must take into account the harsh in-situ environmental conditions, among them micrometeoroids and small debris. Each square meter of the lunar surface is hit at least by two micrometeoroids every year [1], at an average velocity of 13 km.s-1 [2]. The randomness and unpredictability of such a risk lead to consider the implementation of shielding over the critical installations. The abundance of lunar regolith makes it a promising raw material for many applications [3], of which that targeted here. The lab-scale production of fibres out of this material has been recently demonstrated [4]; nevertheless, basalt fibres also turn out to be a reasonable analogue, at a cheaper cost and available in greater amounts. The latter are embedded in a polyamide matrix, which is in fine the composite material used in this work.
Architectured materials are defined as the combination between a structure and at least one constitutive material [5]. This provides the whole architecture properties that could not be reached with the bulk material(s) alone. All the materials found in Nature are actually architectured materials, across all length scales [6]. They also have tailored porosity as a distinctive feature, in combination with various patterns. Crustacean shells, such as the lobster carapace, were selected as a source of inspiration for efficient energy-absorbing panels, as they feature among the most tenacious natural structures ever reported [7][8]. The carapace is a functionally graded material in which porosity increases inwards. The understanding of the underlying energy dissipation mechanisms at various velocities enables to propose bioinspired composite panels with tailored porosity.
Given the level of complexity required by such structures, the continuous filament fabrication technology (belonging to the additive manufacturing processes) was selected. It enables the production of composite materials with a large design freedom and enhanced mechanical strength, compared to the traditional fused filament fabrication process, by taking advantage of the filament anisotropy. Turning the desired architecture into a tangible object requires the generation of a specific printing path, given the continuous nature of the filament. The architectures evaluated in this work through impact testing performed in the middle-velocity range (10 m.s-1), include variations of the material deposition parameters, the angle between adjacent plies, the porosity ratio and the pore aspect ratio.
Architectured materials are defined as the combination between a structure and at least one constitutive material [5]. This provides the whole architecture properties that could not be reached with the bulk material(s) alone. All the materials found in Nature are actually architectured materials, across all length scales [6]. They also have tailored porosity as a distinctive feature, in combination with various patterns. Crustacean shells, such as the lobster carapace, were selected as a source of inspiration for efficient energy-absorbing panels, as they feature among the most tenacious natural structures ever reported [7][8]. The carapace is a functionally graded material in which porosity increases inwards. The understanding of the underlying energy dissipation mechanisms at various velocities enables to propose bioinspired composite panels with tailored porosity.
Given the level of complexity required by such structures, the continuous filament fabrication technology (belonging to the additive manufacturing processes) was selected. It enables the production of composite materials with a large design freedom and enhanced mechanical strength, compared to the traditional fused filament fabrication process, by taking advantage of the filament anisotropy. Turning the desired architecture into a tangible object requires the generation of a specific printing path, given the continuous nature of the filament. The architectures evaluated in this work through impact testing performed in the middle-velocity range (10 m.s-1), include variations of the material deposition parameters, the angle between adjacent plies, the porosity ratio and the pore aspect ratio.