Optimal and adaptive lattice design considering process-induced material anisotropy and geometric inaccuracy for additive manufacturing

2022 ◽  
Vol 65 (1) ◽  
Author(s):  
Shaoying Li ◽  
Shangqin Yuan ◽  
Jihong Zhu ◽  
Weihong Zhang ◽  
Yunlong Tang ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Material Anisotropy ◽  
Lattice Design

Additive Manufacturing: A New Paradigm for the Next Generation of High-Power-Density Direct-Drive Electric Generators

2018 ◽  
Author(s):  
Austin C. Hayes ◽  
Latha Sethuraman ◽  
Lee Jay Fingersh ◽  
Katherine Dykes
Keyword(s):  
Additive Manufacturing ◽  
Power Density ◽  
Systems Engineering ◽  
High Power ◽  
Complex Geometry ◽  
High Reliability ◽  
High Power Density ◽  
Direct Drive ◽  
Sand Cast ◽  
Lattice Design

In recent years, there has been a growing demand for high-power-density direct-drive generators in the wind industry owing to their high reliability, torque per unit volume, and conversion efficiencies. However, direct-drive wind turbine generators are very large, low-speed electric machines, which pose remarkable design and manufacturing issues that challenge their upscaling potential and cost of implementation. With air-gap tolerance as the main design driver, the need for high stiffness shifts the focus toward support-structure design that forms a significant portion of the generator’s total mass. Existing manufacturing processes allow the use of segmented-steel-weldment disk or spoke-arm assemblies that yield stiffer structures per unit mass but tend to be heavier and more expensive to build. As a result, there is a need for a transformative approach to realize lightweight designs that can also facilitate series production at competitive costs. Inspired by recent developments in metal additive manufacturing (AM), we explore a new freedom in the structural design space with a high potential for weight savings in direct-drive generators. This includes the feasibility of using nonconventional complex geometries, such as lattice-based structures as structurally efficient options. Powder-binder jetting of a sand-cast mold was identified as the most feasible AM technology to produce large-scale generator rotor structures with complex geometry. A parametric optimization study was performed and optimized results within deformation and mass constraints were found for each design. The response to the maximum Maxwell stress due to unbalanced magnetic pull was also explored for each design. Further, a topology optimization was applied for each parameter-optimized design to validate results and provide insights into further mass reduction. These novel designs catered for AM are compared in both deflection and mass to conventional rotor designs using NREL’s systems engineering design tool, GeneratorSE. The optimized lattice design with a U-beam truss resulted in a 24% reduction in structural mass of the rotor and 60% reduction in radial deflection. It is demonstrated that additive manufacturing shifts the focus from manufacturability constraints toward lower mass.

On the flexural stiffness of 3D printer thermoplastic

2016 ◽  
Vol 45 (1) ◽  
pp. 59-75 ◽  
Author(s):  
Lawrence Virgin
Keyword(s):  
Additive Manufacturing ◽  
Structural Analysis ◽  
Young’S Modulus ◽  
Flexural Stiffness ◽  
3D Printer ◽  
Material Anisotropy ◽  
Thermoplastic Material ◽  
Load Bearing ◽  
Student Projects ◽  
Compare And Contrast

This paper describes the process of estimating Young’s modulus for the thermoplastic material commonly used in a type of 3D printer. Its twin goals are to compare and contrast a number of simple techniques from elementary structural analysis and to assess the influence of the printer density settings and print orientation (effective material anisotropy). Since components printed using additive manufacturing are used extensively for student projects, often involving load-bearing components, this contribution seeks to shed some light on fundamental modeling issues

Parallelized Additive Manufacturing of Variably Partitioned Volumes for Large Scale 3D Printing With Localized Quality

2020 ◽  
Author(s):  
Mahmoud Dinar
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Large Scale ◽  
Division Problem ◽  
Material Anisotropy ◽  
Need For Support ◽  
One Machine ◽  
Small Working ◽  
Load Conditions ◽  
Missed Opportunity

Abstract Despite the growing application of additive manufacturing (AM) in fabricating complex designs, most machines suffer from small working envelopes and slow processing speeds. One workaround to the problem of small throughput in AM is to partition the volume of a desired object and fabricate sub-volumes in parallel. Prior related work has focused on two problems. One is the geometric division problem, disregarding AM benefits and challenges in determining partitions. Others attempt to install multiple AM processing heads on the same machine, ensuring seamless bonding between deposited material from different heads while avoiding interference among them. A missed opportunity lies in deploying many independent machines simultaneously while considering benefits and limitations of AM. To that end, objects too large to be fabricated on one machine, are divided primarily into cubes that exploit benefits of AM. Specifically, the cubes are hollowed out in the direction of printing to reduce weight while avoiding the need for support structure, and depending on load conditions, packed in different orientations to mitigate material anisotropy.

scholarly journals Design for Additive Manufacturing: Tool Review and a Case Study

2021 ◽  
Vol 11 (4) ◽  
pp. 1571
Author(s):  
Daniel Moreno Nieto ◽  
Daniel Moreno Sánchez
Keyword(s):  
Additive Manufacturing ◽  
Flexible Manufacturing ◽  
Manufacturing System ◽  
Mechanical Design ◽  
Industrial Process ◽  
Design Tools ◽  
Lattice Design ◽  
Complex Shapes ◽  
Study Case

This paper aims to collect in a structured manner different computer-aided engineering (CAE) tools especially developed for additive manufacturing (AM) that maximize the capabilities of this technology regarding product development. The flexibility of the AM process allows the manufacture of highly complex shapes that are not possible to produce by any other existing technology. This fact enables the use of some existing design tools like topology optimization that has already existed for decades and is used in limited cases, together with other novel developments like lattice design tools. These two technologies or design approaches demand a highly flexible manufacturing system to be applied and could not be used before, due to the conventional industrial process limitations. In this paper, these technologies will be described and combined together with other generic or specific design tools, introducing the study case of an additive manufactured mechanical design of a bicycle stem.

scholarly journals Material Anisotropy in Additively Manufactured Polymers and Polymer Composites: A Review

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3368
Author(s):  
Nima Zohdi ◽  
Richard (Chunhui) Yang
Keyword(s):  
Additive Manufacturing ◽  
Complex Geometry ◽  
Research Work ◽  
High Strength ◽  
Layer By Layer ◽  
Material Anisotropy ◽  
Removal Technology ◽  
Subtractive Manufacturing ◽  
Potential Methods ◽  
Manufacturing Technologies

Additive manufacturing (AM) is a sustainable and innovative manufacturing technology to fabricate products with specific properties and complex shapes for additive manufacturable materials including polymers, steels, titanium, copper, ceramics, composites, etc. This technology can well facilitate consumer needs on products with complex geometry and shape, high strength and lightweight. It is sustainable with having a layer-by-layer manufacturing process contrary to the traditional material removal technology—subtractive manufacturing. However, there are still challenges on the AM technologies, which created barriers for their further applications in engineering fields. For example, materials properties including mechanical, electrical, and thermal properties of the additively manufactured products are greatly affected by using different ways of AM methods and it was found as the material anisotropy phenomenon. In this study, a detailed literature review is conducted to investigate research work conducted on the material anisotropy phenomenon of additively manufactured materials. Based on research findings on material anisotropy phenomenon reported in the literature, this review paper aims to understand the nature of this phenomenon, address main factors and parameters influencing its severity on thermal, electrical and mechanical properties of 3D printed parts, and also, explore potential methods to minimise or mitigate this unwanted anisotropy. The outcomes of this study would be able to shed a light on improving additive manufacturing technologies and material properties of additively manufactured materials.

Lattice Structure Design Advisor for Additive Manufacturing Using Gaussian Process

2017 ◽  
Author(s):  
Tsz Ling Elaine Tang ◽  
Yan Liu ◽  
Da Lu ◽  
Erhan Batuhan Arisoy ◽  
Suraj Musuvathy
Keyword(s):  
Additive Manufacturing ◽  
Structural Properties ◽  
Structural Design ◽  
Lattice Structure ◽  
Structure Design ◽  
Structural Performance ◽  
Design Parameters ◽  
Use Case ◽  
Lattice Structures ◽  
Lattice Design

Additive manufacturing (AM) exemplifies the potential of lattice structures to revolutionize structural design. It enables light weight lattice structures to be produced while maintaining the desirable structural performance. Lattice design can vary in different shapes and dimensions. Obtaining the structural performance of a particular lattice structure design is not a straight-forward process. Significant effort is required to perform mechanical testing experiments or to perform finite element analysis (FEA) to characterize the lattice design. In view of that, a guidance system to determine lattice design parameters based on desired functional performance for a specific lattice type is developed, which can be used in interactive design processes and workflows. Homogenization using FEA experiments is applied to characterize the macroscopic lattice structural properties. Mechanical properties of orthotropic cubic lattice f2ccz are estimated. It follows with a design of experiment study to characterize the effective structural properties of 39 lattices with respect to lattice design parameters (unit cell length and strut diameter). A Gaussian process is applied to develop models relating the lattice design parameter to macroscopic structural properties (forward model), and vice versa (inverse model). Both the forward and inverse models are examined and shown to be capable of modeling the FEA experimental dataset of 39 lattices. To illustrate the potential application of the lattice design advisor framework, a structural design use case including lattice part is presented. In the use case, the lattice structure design advisor is proven to be able to estimate an accurate homogenized material property of arbitrary lattice design parameter. This lattice structure design advisor can simplify and streamline the design, modeling and simulation process of lattice-filled structural designs.

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