Architectured Lattice Materials with Tunable Anisotropy: Design and Analysis of the Material Property Space with the Aid of Machine Learning

Abstract

Materials with anisotropic mechanical properties play an important role in nature and technology. Thus, many biomechanical processes in living organisms, which govern their growth, muscular activity, and oxygen and nutrient supply, are based on an anisotropic response of cells to various mechanical stimuli. [1,2] In engineering practice, materials with controlled anisotropy are used in various sensitive structures. [3] Directional dependence of the propagation velocity of acoustic waves stemming from the elastic anisotropy of the medium makes it possible to produce various materials and devices for breaking acoustic waves or damping of vibrations. [4] These are but a few illustrations of the significance of mechanical anisotropy. Elastic anisotropy can be achieved in many ways. In composites, it is produced using a special arrangement of the constituents. [5] The paradigm of architectured materials, [6,7] also referred to in the literature as hybrid materials, or metamaterials, and for brevity called archimats in the following, opens remarkable new possibilities for creating anisotropic properties. It builds on the idea of Ashby that the inner architecture of a material can be regarded as an extra "degree of freedom" in materials design, which can be exploited to provide the material with desired properties. [8] Some architectured materials with artificially created mechanical anisotropy are already in existence; see the previous studies. [3,4,9,10] Among them, periodic beam lattice materials take a special place due to the variability of properties they possess. [6] The properties are determined by the architecture of the elementary cell of the lattice. Commonly, it is the lattice geometry that is varied to achieve targeted characteristics of the material, while

Architecturing materials at mesoscale: some current trends

“…The design with lattices containing a meso scale structure with elements of different kinds represents a new evolutionary step in the development of this research area [52,53]. A meso structure is a spatial pattern formed [44], (b) sponge-inspired material with high buckling resistance [46], (c) hinged lattice with a giant Poisson's ratio [50], (d) material with a zero Poisson's ratio [49], (e) programmable metamaterial for energy dissipation with fully reversible deformation [45], (f) damage-tolerant material inspired by crystal microstructure [51], (g) fault-tolerant material [47], (h) three-dimensional auxetic with omnidirectional Poisson's ratio [48].…”

Buckling and postbuckling of architectured materials: A review of methods for lattice structures and metal foams

“…Examples are the design of archimats with desired stiffness properties, [101][102][103] with a desired auxetic behaviour, 56,57,104,105 with tailored buckling mechanisms at the microscale 106 or with an artificially designed anisotropy. 107,108 For obtaining the desired effective properties of archimats, either the internal architecture 3 in terms of the orientation 102 and aspect ratios 106,109 of the individual structural members can be modified or a combination of different base materials can be utilized. 29,104,107 Additionally, manufacturing defects can have a strong impact on the mechanical behaviour of archimats 17,18,55 and consequently have to be considered in the design process.…”

“…107,108 For obtaining the desired effective properties of archimats, either the internal architecture 3 in terms of the orientation 102 and aspect ratios 106,109 of the individual structural members can be modified or a combination of different base materials can be utilized. 29,104,107 Additionally, manufacturing defects can have a strong impact on the mechanical behaviour of archimats 17,18,55 and consequently have to be considered in the design process.…”

The Emergence of Sequential Buckling in Reconfigurable Hexagonal Networks Embedded into Soft Matrix

“…Cellular lattice structures assembled from repeating cells are widely known for their superior combination of low weight and high mechanical properties [ 1 , 2 , 3 ]. In general, the mechanical performance of lattices is defined by the geometry of the unit cells [ 4 , 5 , 6 , 7 ], and rational design of the internal architecture enables the engineering of lattices with enhanced stiffness [ 8 , 9 ], controlled anisotropy of mechanical properties [ 10 , 11 ], or lattices that are tolerant to partial failure [ 12 , 13 ]. Unsurprisingly, many mechanical metamaterials can be considered as successors of cellular materials [ 14 , 15 ].…”