A class of elastic isotropic plate lattice materials with near-isotropic yield stress

Thoughtfully engineered lattice materials offer a canvas for tailoring a diverse range of mechanical attributes. Yet, their pronounced anisotropy and inherently unstable nonlinear mechanical behavior curtail their suitability for energy absorption applications. Here, we propose the adoption of lightweight plate lattice structures for energy absorption and loading support. This involves strategically integrating plates into the rhombic dodecahedron framework, facilitating elastic isotropy and nearly yield isotropy. The proposed plate lattices showcase remarkable properties, including an exceptionally high bulk modulus that reaches the HS bound. Moreover, they boast an enhanced energy absorption capacity, surpassing that of the rhombic dodecahedron truss lattice by up to 2.58 times. The effects of relative density and loading direction on the mechanical properties were thoroughly explored through numerical simulations. Simulation predictions were rigorously validated through experimental verification. The failure modes of plate samples transition from being dependent on the loading direction, leading to collapse, to becoming stable regardless of the loading direction as the relative density increases from 0.1 to 0.2. It is noteworthy that plate lattices demonstrate SEA values comparable to those of shell lattices, even surpassing the stiffest isotropic plate lattice. These characteristics underscore their potential for applications in loading support and energy absorption.