An investigation of mechanical properties and energy absorption behavior of foam-filled 3D-printed sandwich structures

The objective of this study is to investigate the compressive behavior and energy absorption performance of two-dimensional (3D)-printed foam-filled sandwich structures through both experimental and computational approaches. Four different structural configurations, including honeycomb, reentrant, zero Poisson’s ratio, and modified reentrant designs, were developed to analyze the influence of microstructure and Poisson’s ratio on the mechanical response of the metamaterials. The results showed that energy absorption behavior strongly depends on the structural topology and deformation mechanism rather than Poisson’s ratio alone. Among the unfilled structures, the zero Poisson’s ratio configuration exhibited the highest specific energy absorption, while the modified auxetic structure demonstrated improved plateau stability and enhanced performance compared to the conventional reentrant design. Additionally, the influence of foam filling on the mechanical behavior of the structures was investigated. The compressive test results indicated that foam filling significantly improved the mechanical response and energy absorption properties of all configurations. Furthermore, finite element simulations were performed to model the compressive behavior of the 3D-printed structures, generally showing good agreement with the experimental results and successfully capturing the overall deformation and energy absorption trends. These findings demonstrate that both topology optimization and foam filling are effective strategies for enhancing the energy absorption performance of 3D-printed sandwich structures.