Fig. 1 Typical force-relative displacement of an auxetic tetra-anti-chiral structure More

Fig. 2 The procedure for the construction of the numerical models: ( a ) construction of the 3D—fully solid elements numerical model and ( b ) application for the construction of the 2.5D beam finite element model More

Fig. 3 Definition of the numerical models for the convergence analysis. Letter C followed by a digit defines the configuration case while the numbers are the parentheses represent the elements used through-thickness, along the length of the patch, and along the ligament. The lengths of the ligam... More

Fig. 4 Convergence analysis: ( a ) cumulated results for the compression analysis and ( b ) cumulated results for the buckling analysis More

Fig. 5 The free-body diagram of the unit cell More

Fig. 6 ( a ) The variation of Poisson’s ratio as a function of the radius of the node is presented. The ligaments were considered of equal lengths (20 mm) and ( b ) the variation of Poisson’s ratio as a function of the length of the ligaments is presented. The value of the radius of the node was s... More

Fig. 7 ( a ) The variation of Poisson’s ratio as a function of the thickness and width of the ligaments is presented. The thickness of the vertical ligaments ( t y ) is equal to the thickness of the horizontal ligaments ( t x ) and ( b ) slight adjustments of Poisson’s ratio can be performed... More

Fig. 8 Geometrical features: ( a ) the geometrical dimension of the unit cell and ( b ) formulation of the geometrical model More

Fig. 9 A series of structures was defined using the paraments detailed in Table 2 . The case is identified by the corresponding letter. More

Fig. 10 Numerical and theoretical results for structures with a different number of units along the vertical axis More

Fig. 11 Buckling analysis of the beam finite elements model: ( a ) numerical model of the node with a small radius, ( b ) overview of the full numerical model, and ( c ) buckling mode of the structure More

Fig. 12 Numerical models for buckling analysis More

Fig. 13 ( a ) 3D numerical model of the unit, ( b ) 2.5D numerical model of the unit, and ( c ) geometrical features of the connection between the ligament and central node (it is assumed that L x = L y = L ) More

Fig. 1 Schematic representation of the prime concepts of this study: ( a ) schematic of a half-cell consisting of a porous silicon electrode coupled with Li metal, separated by a separator and ( b ) magnified view of silicon particles and the surrounding CBD, and pore phase in the pristine state (... More