Optimal design of three-dimensional non-uniform nylon lattice structures for selective laser sintering manufacturing

Xin Jin,Meng Zhang,Guo Xi Li

doi:10.1177/1687814018790833

Abstract

As a kind of novel multifunctional structure with three-dimensional pores characterized by low relative density, lattice structures can attain a lightweight design while maintaining high specific mechanical properties in three-dimensional solid structures. Focusing on the challenge of finding the optimal design of lattice structures in the design object, a design and modeling method of non-uniform three-dimensional lattice structures is proposed while ensuring the selective laser sintering manufacturability. Optimization for cell type, cell size, and strut size distribution of lattices is specified with the mechanical properties analyzed and the material model calculated beforehand. The manufacturing constraints are analyzed and expressed in topology optimization and the optimal distribution of topology optimization results is mapped to the strut size distribution of lattice cells. The rapid and automatic computer-aided design modeling of optimized structures is realized by the parametric definition and assembling of lattice components. Finally, the non-uniform structures are successfully manufactured by selective laser sintering and it is shown by means of finite element analysis and experiments that the proposed design approach can improve the mechanical performance compared to the uniform lattice structure under the same weight reduction. And for the design object in this study, body-centered structure with cell size [Formula: see text]mm is chosen as the optimal cell type and cell size under the given selective laser sintering manufacturing constraints.

Highlights

In recent years, with the rapid development of material preparation and forming technology, cellular structures emerge as a kind of novel multifunctional lightweight structure with two-dimensional (2D) or threedimensional (3D) pores characterized by low relative density.[1]
We introduce an approach to optimize the design of 3D non-uniform lattice structures for selective laser sintering (SLS) with the lattice cell as the design unit
We focus on lattices with cube envelope, namely, the four kinds of lattices shown in Figure 3, for cube envelope, can facilitate the arrangement of lattices and the boundary in the 3D solid model is regular

Summary

Introduction

With the rapid development of material preparation and forming technology, cellular structures emerge as a kind of novel multifunctional lightweight structure with two-dimensional (2D) or threedimensional (3D) pores characterized by low relative density.[1] They keep material only in the vital regions of a part to attain a lightweight structure while maintaining the high specific mechanical properties such as strength,[2] shock resistance,[3] heat transfer and insulation,[4] and energy absorption. Lattice-based cellular structures offer stiffer and stronger materials over foams. Compared to honeycombs with 2D pores, the potential fully open 3D interior structures of lattices facilitate multifunctional applications[6] and enable design freedom in the 3D domain

Methods

Results

Conclusion