Novel design of closed-cell foam structures for property enhancement

Abstract

Cellular materials, such as foams, can be used as load bearing members in civil construction and as protective energy absorbing structures for personnel and equipment. In the present study, novel lightweight closed-cell structures were designed, and their mechanical properties and collapse mechanisms were investigated through a combination of experimental validation and finite element (FE) simulations. Selected porous structure designs were manufactured from acrylonitrile butadiene styrene (ABS) using additive manufacturing technology. These 3D printed structures were subjected to quasi-static loading to determine the dependence of their elastic and plastic responses from their topological features. Deformation mechanisms were elucidated through quasi-static compression experiments and FE modelling. The appropriate distribution of the base material in the designed closed-cell structures inherits the merits of uniform stress distribution and large deformations that lead to reaching high strengths and desirable energy absorption efficiencies. The effects of relative density and cell shape were studied in detail from elastic loading through the large plastic strain densification regions. The effects of cellular architecture on deformation mechanisms and energy absorption capabilities demonstrated the possibility of enhancing energy absorption efficiencies with appropriate design criteria. Based on the experimental and numerical analyses, the most efficient energy absorbing closed-cell structure was proposed.