Design of lightweight tree-shaped internal support structures for 3D printed shell models

Abstract

Purpose The purpose of this paper is to design a lightweight tree-shaped internal support structure for fused deposition modeling (FDM) three-dimensional (3D) printed shell models. Design/methodology/approach A hybrid of an improved particle swarm optimization (PSO) and greedy strategy is proposed to address the topology optimization of the tree-shaped support structures, where the improved PSO is different from traditional PSO by integrating the best component of different particles into the global best particle. In addition, different from FEM-based methods, the growing of tree branches is based on a large set of FDM 3D printing experiments. Findings The proposed improved PSO and its combination with a greedy strategy is effective in reducing the volume of the tree-shaped support structures. Through comparison experiments, it is shown that the results of the proposed method outperform the results of recent works. Research limitations/implications The proposed approach requires the derivation of the function of the yield length of a branch in terms of a set of critical parameters (printing speed, layer thickness, materials, etc.), which is to be used in growing the tree branches. This process requires a large number of printing experiments. To speed up this process, the users can print a dozen of branches on a single build platform. Thereafter, the users can always use the function for the fabrication of the 3D models. Originality/value The proposed approach is useful for the designers and manufacturers to save materials and printing time in fabricating the shell models using the FDM technique; although the target is to minimize the volume of internal support structures, it is also applicable to the exterior support structures, and it can be adapted to the design of the tree-shaped support structures for other AM techniques such as SLA and SLM.

Utilizing Fractals for Modeling and 3D Printing of Porous Structures

“…See [72,73] for the details. It is worth mentioning that self-similar structures created by tree-like fractals have been used to reinforce a 3D printed structure [75,76]. In this case, solid models, not the point cloud, of the self-similar segments are used, which is not the focus in this study.…”

Escaping Tree-Support (ET-Sup): minimizing contact points for tree-like support structures in additive manufacturing

“…Generating tree-supports can be described as the Euclidean Steiner Minimal Tree problem, which is at least NP-hard (Vanek et al , 2014). Zhu et al (2019b, 2019c) used a hybrid of a particle swarm optimization and a greedy algorithm to design the tree-supports. The method saves up to 8% material and 13% print time compared to the results obtained by the Autodesk Meshmixer (Schmidt and Umetani, 2014), and it has a computation time from minutes to hours.…”

“…This kind of support is reliable, but they are notoriously harder to remove and more likely to damage the model. Another type of supports is the tree-like supports (Zhu et al , 2019c), which grow branches to touch the overhangs [Figure 1(b)]. Tree supports use less material and have less contacts with the overhangs, so that they are easier to remove and cause less damage.…”

A hybrid of genetic algorithm and particle swarm optimization for reducing material waste in extrusion-basedadditive manufacturing

“…Zhang et al (2019) proposed a local barycenter-based tree-support algorithm that has the nice property of higher efficiency and less material consumption. Zhu et al (2019aZhu et al ( , 2019b proposed a hybrid of PSO and greedy algorithm to minimize the support volume of the tree-supports (Figure 1(c)) for 3D printed models. Zhou et al (2019) used the Lindenmayer system (Lsystem) to simulate the plants' growing process to generate a symmetric tree-support and eliminated branches without intersecting the 3D model.…”