Influence of Geometric and Manufacturing Parameters on the Compressive Behavior of 3D Printed Polymer Lattice Structures.

Rafael Guerra Silva,Gustavo Morales Pavez,Cristóbal Salinas Estay,María Josefina Torres,Jorge Zahr Viñuela

doi:10.3390/ma14061462

Rafael Guerra Silva, Gustavo Morales Pavez + Show 3 more

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https://doi.org/10.3390/ma14061462

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Abstract

Fused deposition modeling represents a flexible and relatively inexpensive alternative for the production of custom-made polymer lattices. However, its limited accuracy and resolution lead to geometric irregularities and poor mechanical properties when compared with the digital design. Although the link between geometric features and mechanical properties of lattices has been studied extensively, the role of manufacturing parameters has received little attention. Additionally, as the size of cells/struts nears the accuracy limit of the manufacturing process, the interaction between geometry and manufacturing parameters could be decisive. Hence, the influence of three geometric and two manufacturing parameters on the mechanical behavior was evaluated using a fractional factorial design of experiments. The compressive behavior of two miniature lattice structures, the truncated octahedron and cubic diamond, was evaluated, and multilinear regression models for the elastic modulus and plateau stress were developed. Cell size, unit cell type, and strut diameter had the largest impact on the mechanical properties, while the influence of feedstock material and layer thickness was very limited. Models based on factorial design, although limited in scope, could be an effective tool for the design of customized lattice structures.

Highlights

Additive manufacturing (AM) opens up new opportunities for the development of novel materials, as they are capable of generating complex custom-made lattice structures in three-dimensions with precise control over the size and shape of both cells and struts, and the overall topology of the structure [1]
The design, simulation and fabrication of lattices built via AM have attracted attention, and different methods have been proposed to predict the mechanical performance of lattice structures [8]
This could be of special interest in miniature lattice structures, as the dimension of the struts is relatively small and the staircase effect could have a negative impact [38,39]: the interaction between strut orientation and layer thickness affects the accuracy of struts in AM and could cause significant changes in mechanical properties, as strut thickness must grow larger if the angle between the strut and the horizontal plane increases to secure adequate adhesion between layers

Summary

Introduction

Additive manufacturing (AM) opens up new opportunities for the development of novel materials, as they are capable of generating complex custom-made lattice structures in three-dimensions with precise control over the size and shape of both cells and struts, and the overall topology of the structure [1]. The characterization of a multitude of lattice configurations manufactured using diverse AM methods such as fused deposition modeling [7,10,11,12,13], stereolithography [14,15,16], jet fusion [17,18,19], and selective laser sintering [20,21] is currently a very active topic in research, in addition to the development of diverse analytical and numerical methods for the design of lattice structures [22,23,24,25]. The influence of diverse geometric parameters (unit cell type, cell size, cell orientation, strut thickness, strut cross-section, etc.) on the mechanical properties of lattice structures has been investigated by analytical, numerical, and experimental techniques [7,26,27,28,29,30,31]. Scaling law models have been used to model the relationship between strut diameter, cell size, and mechanical properties [22,28], and have been validated experimentally [7,29,30,31]

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