Print Email Facebook Twitter Non-auxetic mechanical metamaterials Title Non-auxetic mechanical metamaterials Author de Jonge, Christa P. (Student TU Delft) Kolken, H.M.A. (TU Delft Biomaterials & Tissue Biomechanics) Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics) Date 2019 Abstract The concept of "mechanical metamaterials" has become increasingly popular, since their macro-scale characteristics can be designed to exhibit unusual combinations of mechanical properties on the micro-scale. The advances in additive manufacturing (AM, three-dimensional printing) techniques have boosted the fabrication of these mechanical metamaterials by facilitating a precise control over their micro-architecture. Although mechanical metamaterials with negative Poisson's ratios (i.e., auxetic metamaterials) have received much attention before and have been reviewed multiple times, no comparable review exists for architected materials with positive Poisson's ratios. Therefore, this review will focus on the topology-property relationships of non-auxetic mechanical metamaterials in general and five topological designs in particular. These include the designs based on the diamond, cube, truncated cube, rhombic dodecahedron, and the truncated cuboctahedron unit cells. We reviewed the mechanical properties and fatigue behavior of these architected materials, while considering the effects of other factors such as those of the AM process. In addition, we systematically analyzed the experimental, computational, and analytical data and solutions available in the literature for the titanium alloy Ti-6Al-4V. Compression dominated lattices, such as the (truncated) cube, showed the highest mechanical properties. All of the proposed unit cells showed a normalized fatigue strength below that of solid titanium (i.e., 40% of the yield stress), in the range of 12-36% of their yield stress. The unit cells discussed in this review could potentially be applied in bone-mimicking porous structures. Subject FatigueLattice structuresMechanical metamaterialsNon-auxeticVolume-preserving materials To reference this document use: http://resolver.tudelft.nl/uuid:f1e3aca9-13db-42b1-b9ff-73c396f2c2ec DOI https://doi.org/10.3390/ma12040635 ISSN 1996-1944 Source Materials, 12 (4) Part of collection Institutional Repository Document type review Rights © 2019 Christa P. de Jonge, H.M.A. Kolken, A.A. Zadpoor Files PDF materials_12_00635.pdf 2.43 MB Close viewer /islandora/object/uuid:f1e3aca9-13db-42b1-b9ff-73c396f2c2ec/datastream/OBJ/view