Fig. 2: Buckling of chiral and non-chiral rods.
From: Large recoverable elastic energy in chiral metamaterials via twist buckling
a,b, Angled non-chiral rods. c–f, Chiral rods. a, Normalized force (F1rod/Fs) versus macroscopic strain (ε = s/L0 sin θ) of angled rods with oblique angle θ. Micro-bending imperfection is included here. b, Normalized energy (U1rod/Us) under different maximal von Mises stresses (σv) versus θ of perfectly straight rods. c, Theoretical force–strain curves of typical chiral models. Filled circles are points for σv = 0.1Es. None of the curves reach σv = 0.2Es at ε = 0.2. d, Proportions of energy from different deformation modes. e, Energy–stress plot of straight rods with 2r/L0 = 0.1 (U1rod/Us versus σv/Es). Discrete points are FEA results for R = 7 mm. f, Influence of initial angle (α0) and radius (R) on U1rod/Us at ε = 0.2.
