Materials & Design (Jul 2023)
Mechanical design of a convex-deformable polymer plate
Abstract
The authors’ previous study introduced a convex-deformable sandwich plate consisting of a pyramid truss core and two face sheets that exhibit a two-dimensional auxetic pattern. Owing to its unique micro-architecture, the sandwich plate successfully underwent adequate convex deformation under bending, even when many chips were embedded in its core. However, the plate was fabricated by adhesively bonding stainless-steel face sheets to a polymer truss core, and this fabrication process was complex and expensive. Moreover, the detailed dimensions of this plate were determined iteratively through trial-and-error. In this study, we develop a fresh approach to monolithically fabricate the entire body of the auxetic plate from a polymer by using three-dimensional printing. First, three mechanical constraints, which are needed for designing the face sheets and the core to realize compliant and convex deformation, unlike that of an ordinary sandwich plate, are defined. A precise mechanical design procedure is applied for dimensional optimization of the plate, and the mechanical behaviors of the fabricated specimen are observed by subjecting it to tensile and bending loads. The optimally designed polymer specimen exhibited a high level of convex deformation, as indicated by its adequate flexural rigidity (D = 0.0565 Nm2) and curvature ratio (0.625) when bent to the minimum curvature radius of ρ = 150 mm.
