Support Structures Optimisation for High-Quality Metal Additive Manufacturing with Laser Powder Bed Fusion: A Numerical Simulation Study

Abstract

This study focuses on Metal Additive Manufacturing (AM), an emerging method known for its ability to create lightweight components and intricate designs. However, Laser Powder Bed Fusion (LPBF), a prominent AM technique, faces a major challenge due to the development of high residual stress, resulting in flawed parts and printing failures. The study’s goal was to assess the thermal behaviour of different support structures and optimised designs to reduce the support volume and residual stress while ensuring high-quality prints. To explore this, L-shaped specimens were printed using block-type support structures through an LPBF machine. This process was subsequently validated through numerical simulations, which were in alignment with experimental observations. In addition to block-type support structures, line, contour, and cone supports were examined numerically to identify the optimal solutions that minimise the support volume and residual stress while maintaining high-quality prints. The optimisation approach was based on the Design of Experiments (DOE) methodology and multi-objective optimisation. The findings revealed that block supports exhibited excellent thermal behaviour. High-density supports outperformed low-density alternatives in temperature distribution, while cone-type supports were more susceptible to warping. These insights provide valuable guidance for improving the metal AM and LPBF processes, enabling their broader use in industries like aerospace, medical, defence, and automotive.

An Interactive Web-Based Platform for Support Generation and Optimisation for Metal Laser Powder Bed Fusion

“…The support optimisation module is an interactive engine that provides optimisation suggestions for commonly used geometries in metal AM and PBF-LB/M systems, including block, line, contour, and cones support structures. The optimisation results are based on the authors' previously published work [14], where the thermal behaviour of the above-mentioned support types was studied aiming to minimise support volume and residual stress while maintaining the quality of prints. Specifically, support density and tooth area were examined using various support parameters, including x, y hatching, tooth height, and tooth top length, while design of experiments (DOE) methodology was employed to create support alternatives.…”

“…This feedback is displayed on the four grey horizontal sliders beneath. Here, it should be restated that the optimisation results are exclusively based on the findings of the authors' previously published work [14], where the thermal behaviour of the four mentioned support types, using L-shaped specimens made of titanium, was investigated. Subsequent experimentation and data collection are anticipated to enhance the functionality of the support optimisation engine, incorporating more input parameters and optimisation outputs such as support removability.…”

“…This is directed towards the fabrication of optimised metal support structures capable of addressing these conditions and thereby eliminating defects such as warping, distortion, cracks, and part delamination. These studies are highlighted in the literature section of another author's earlier published work [14], where the thermal behaviour of four common support structures used in metal AM was investigated. The aim was to propose optimal parameters that minimise support volume and residual stress while ensuring high-quality printed outcomes.…”

“…In this research, for the first time, an initial release of an interactive web-based platform for support generation and optimisation is proposed. The platform allows users to import 3D files, determine part orientation, generate and visualise block-type support structures with diamond perforations using the open-source PySLM library developed by Luke Parry [22], access optimisation suggestions for block, line, contour, and cone supports based on the author's prior research [14], perform thermomechanical simulations to anticipate the thermal performance of the imported part, as well as export the prepared assembly for further processing. The platform targets not only professionals but also intermediate users involved in metal AM, providing user-friendly functionality within a simple interface.…”

Experimental and Numerical Investigation of the Use of Ultrasonic Waves to Assist Laser Welding

“…In the solid mechanics domain, reflective boundaries are applied at the area of the welding molten pool. A comprehensive thermal simulation was conducted by Dimopoulos et al [ 33 ]; however, in this simulation, only the effect of heating on vibration transmission to the molten pool area is considered. In the domain of electrostatics, the behaviour of piezoelectric ceramics is governed solely by the equations of solid mechanics.…”