3D lightweight mechanical metamaterial with nearly isotropic inelastic large deformation response

Well-designed stretching-dominated lattices can form elastic metamaterials with high specific stiffness and strength. Their strongly anisotropic unstable nonlinear mechanical properties, however, limit their application to energy absorption. In contrast, bending-dominated are well known for absorption capacity stable response, but poor response. Here, we propose a new class of light-weight isotropic truss lattice that combines both advantages. Numerical simulations reveal the proposed not only exhibit isotropy, also nearly inelastic large deformation particular, relative density smaller than 1% metamaterial almost attains upper bound Poisson’s ratio an material, i.e ν=0.5. Compared BCC lattices, uniaxial compression tests show modulus is twice as large, collapse strength about 1.6 times large. The designed thus noteworthy alternative load bearing, absorption, transformation acoustics.