Energy Absorption and Mechanical Performance of Functionally Graded Soft–Hard Lattice Structures

Abstract

Today, the rational combination of materials and design has enabled the development of bio-inspired lattice structures with unprecedented properties to mimic biological features. The present study aims to investigate the mechanical performance and energy absorption capacity of such sophisticated hybrid soft–hard structures with gradient lattices. The structures are designed based on the diversity of materials and graded size of the unit cells. By changing the unit cell size and arrangement, five different graded lattice structures with various relative densities made of soft and hard materials are numerically investigated. The simulations are implemented using ANSYS finite element modeling (FEM) (2020 R1, 2020, ANSYS Inc., Canonsburg, PA, USA) considering elastic-plastic and the hardening behavior of the materials and geometrical non-linearity. The numerical results are validated against experimental data on three-dimensional (3D)-printed lattices revealing the high accuracy of the FEM. Then, by combination of the dissimilar soft and hard polymeric materials in a homogenous hexagonal lattice structure, two dual-material mechanical lattice statures are designed, and their mechanical performance and energy absorption are studied. The results reveal that not only gradual changes in the unit cell size provide more energy absorption and improve mechanical performance, but also the rational combination of soft and hard materials make the lattice structure with the maximum energy absorption and stiffness, in comparison to those structures with a single material, interesting for multi-functional applications.

Design and Characterization of Asymmetric Cell Structure of Auxetic Material for Predictable Directional Mechanical Response

“…Another benefit of AM is the possibility of manufacturing cellular structures [ 2 ] or complex configurations generally formed by interconnected nodes and struts that maintain a periodic pattern [ 3 , 4 ]. These structures can present multiple attractive properties depending on the specific application, such as light weight, high specific stiffness, and high energy absorption capacity [ 5 , 6 , 7 , 8 , 9 ]. Sandwich panel fabrication is one of the most widely studied and reported in the literature [ 10 , 11 , 12 , 13 , 14 , 15 ].…”

Fast 3D Printing with Chitosan/Polyvinyl alcohol/Graphene Oxide Multifunctional Hydrogel Ink that has UltraStretch Properity

“…3D printing technology provided a great help for manufacturing of complex shapes and structures [11] . The optimization of structural design combined with finite element modeling (FEM) can further improve energy absorption and performance [12] . Through geometric modeling and topology‐optimization (TO), some nonlinear soft materials can be predicted when used to design structures [13,14] .…”

“…[11] The optimization of structural design combined with finite element modeling (FEM) can further improve energy absorption and performance. [12] Through geometric modeling and topology-optimization (TO), some non-linear soft materials can be predicted when used to design structures. [13,14] Simultaneously, machine learning (ML) gives 3D printing a unique advantage in the field of manufacturing soft robots with special geometric requirements.…”

Design of Hierarchical Architected Lattices for Enhanced Energy Absorption

“…Lattices have emerged as the main candidates for energy absorption structures and have been extensively studied [ 6 , 7 , 8 ]. Lattice unit cells are typically designed to harness instabilities and maximize buckling to increase energy absorption [ 9 , 10 ].…”