Abstract
A nonreciprocal gel consisting of hydrogel and nanosheet exhibits mechanical nonreciprocity, which has potential applications in mechanical engineering. An earlier study has revealed that this mechanical nonreciprocity is triggered by the tension-compression asymmetry resulting from the microscopic buckling behavior of nanosheets during compressive deformation, but the relevant influencing factors remain unknown. In this study, we investigate the microscopic buckling behavior and the resultant tension-compression asymmetry in a nonreciprocal gel subjected to uniaxial conditions. Eigenvalue buckling and post-buckling analyses equipped with computational homogenization are performed on a unit cell modeled as an elastic bilayer for which ratios of Young’s modulus and thickness are parameterized. The results confirm that selecting a dilute microscopic buckling with the characteristic wavelength or a non-dilute microscopic buckling with the infinite wavelength hinges on the ratios of Young’s modulus and thickness, which is consistent with the theoretical solution for the buckling behavior of a layered composite. We also elucidate that the tension-compression asymmetry is more pronounced as the Young’s modulus ratio increases or the thickness ratio decreases.