Table 2 The dimensions of the system (in mm) in Fig. 5 together with the strains and Poisson’s ratio computed. System A is considered as the initial structure
From: Mathematical modeling of auxetic systems: bridging the gap between analytical models and observation
|  | Dimensions | Strains in y-direction | Strains in x-direction | Poisson’s ratio ν21 | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
X22 | X11 | \( {e}_2^{eng} \) | δε2 | \( {e}_2^{true} \) | \( {e}_2^{eng} \) | δε2 | \( {e}_2^{true} \) | Eng. | Instant | True | |
A | 30 | 25 | Â | Â | Â | Â | Â | Â | Â | Â | Â |
B | 34 | 22 | 0.133 | 0.133 | 0.125 | -0.120 | -0.120 | -0.128 | 0.900 | 0.900 | 1.021 |
C | 38 | 17 | 0.267 | 0.118 | 0.236 | -0.320 | -0.227 | -0.386 | 1.200 | 1.932 | 1.631 |
D | 42 | 17 | 0.400 | 0.105 | 0.336 | -0.320 | 0.000 | -0.386 | 0.800 | 0.000 | 1.146 |
E | 46 | 23 | 0.533 | 0.095 | 0.427 | -0.080 | 0.353 | -0.083 | 0.150 | -3.706 | 0.195 |
F | 50 | 25 | 0.667 | 0.087 | 0.511 | 0.000 | 0.087 | 0.000 | 0.000 | -1.000 | 0.000 |
G | 54 | 28 | 0.800 | 0.080 | 0.588 | 0.120 | 0.120 | 0.113 | -0.150 | -1.500 | -0.193 |
H | 58 | 31 | 0.933 | 0.074 | 0.659 | 0.240 | 0.107 | 0.215 | -0.257 | -1.446 | -0.326 |
I | 62 | 27 | 1.067 | 0.069 | 0.726 | 0.080 | -0.129 | 0.077 | -0.075 | 1.871 | -0.106 |