Comparative Study on the Uniaxial Behaviour of Topology-Optimised and Crystal-Inspired Lattice Materials

Chengxing Yang,Kai Xu,Suchao Xie

doi:10.3390/met10040491

Abstract

This work comparatively studies the uniaxial compressive performances of three types of lattice materials, namely face-centre cube (FCC), edge-centre cube (ECC), and vertex cube (VC), which are separately generated by topology optimisation and crystal inspiration. High similarities are observed between the materials designed by these two methods. The effects of design method, cell topology, and relative density on deformation mode, mechanical properties, and energy absorption are numerically investigated and also fitted by the power law. The results illustrate that both topology-optimised and crystal-inspired lattices are mainly dominated by bending deformation mode. In terms of collapse strength and elastic modulus, VC lattice is stronger than FCC and ECC lattices because its struts are arranged along the loading direction. In addition, the collapse strength and elastic modulus of the topology-optimised FCC and ECC are close to those generated by crystal inspiration at lower relative density, but the topology-optimised FCC and ECC are obviously superior at a higher relative density. Overall, all topology-generated lattices outperform the corresponding crystal-guided lattice materials with regard to the toughness and energy absorption per unit volume.

Highlights

As a mimic of nature cellular material, lattice material is designed with its unit cells arranged periodically along tessellation directions
Our objective is to systematically explore the similarities and differences of three types of lattice materials guided by two methods, i.e., topology optimisation and crystal inspiration
The relative density of the generated cells varies in the interval [0.1, 0.3], which is comparable to that of aerogel, alumina nanolattices, and other ultralight materials [45]

Summary

Introduction

As a mimic of nature cellular material, lattice material is designed with its unit cells arranged periodically along tessellation directions. Methods for lattice material design can be generally classified into two categories, i.e., manual generation and mathematical generation [5]. Manual generation means designing a lattice material by using beams and trusses with joints modified to create seamless transitions between unit cell elements [5]. There are numerous manually designed lattice materials and some of them are inspired by crystal structures. Lozanovski et al [19,20] numerically investigated the strut defects of lattice materials fabricated by the AM method, and a Monte Carlo simulation-based approach was proposed to predict the stiffness of a lattice material with defects

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Results

Discussion

Conclusion