Designing for Additive Manufacturing: Lightweighting Through Topology Optimization Enables Lunar Spacecraft

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Melissa E. Orme ◽  
Michael Gschweitl ◽  
Michael Ferrari ◽  
Ivan Madera ◽  
Franck Mouriaux
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Preliminary Design ◽  
Powder Bed ◽  
Lunar Landing ◽  
Rigorous Testing ◽  
Numerical Effort ◽  
Engine Mount ◽  
Development Approach

An end-to-end development approach for space flight qualified additive manufacturing (AM) components is presented and demonstrated with a case study consisting of a system of five large, light-weight, topologically optimized components that serve as an engine mount in SpaceIL's GLPX lunar landing craft that will participate in the Google Lunar XPrize challenge. The development approach includes a preliminary design exploration intended to save numerical effort in order to allow efficient adoption of topology optimization and additive manufacturing in industry. The approach also addresses additive manufacturing constraints, which are not included in the topology optimization algorithm, such as build orientation, overhangs, and the minimization of support structures in the design phase. Additive manufacturing is carried out on the topologically optimized designs with powder bed laser technology and rigorous testing, verification, and validation exercises complete the development process.

Additive Manufacturing Constraints in Topology Optimization for Improved Manufacturability

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Kunal Mhapsekar ◽  
Matthew McConaha ◽  
Sam Anand
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Experimental Validation ◽  
Manufacturing Processes ◽  
Manufacturing Constraints ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
And Topology ◽  
Am Processes

Additive manufacturing (AM) provides tremendous advantage over conventional manufacturing processes in terms of creative freedom, and topology optimization (TO) can be deemed as a potential design approach to exploit this creative freedom. To integrate these technologies and to create topology optimized designs that can be easily manufactured using AM, manufacturing constraints need to be introduced within the TO process. In this research, two different approaches are proposed to integrate the constraints within the algorithm of density-based TO. Two AM constraints are developed to demonstrate these two approaches. These constraints address the minimization of number of thin features as well as minimization of volume of support structures in the optimized parts, which have been previously identified as potential concerns associated with AM processes such as powder bed fusion AM. Both the manufacturing constraints are validated with two case studies each, along with experimental validation. Another case study is presented, which shows the combined effect of the two constraints on the topology optimized part. Two metrics of manufacturability are also presented, which have been used to compare the design outputs of conventional and constrained TO.

Multi-Component Topology Optimization for Powder Bed Additive Manufacturing (MTO-A)

2018 ◽  
Author(s):  
Yuqing Zhou ◽  
Tsuyoshi Nomura ◽  
Kazuhiro Saitou
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Simultaneous Optimization ◽  
Previous Attempt ◽  
Numerical Instability ◽  
Feature Size ◽  
Powder Bed ◽  
Nonlinear Projection ◽  
Gradient Based ◽  
Length Width

This paper presents a gradient-based multi-component topology optimization (MTO) method for structures assembled from components made by powder bed additive manufacturing. It is built upon our previous work on the continuously-relaxed MTO framework utilizing the concept of fractional component membership. The previous attempt on the integration of the relaxed MTO framework with additive manufacturing constraints, however, suffered from numerical instability for larger size problems, limiting its application to 2D low-resolution examples. To overcome this difficulty, this paper proposes an improved MTO formulation based on a design field regularization and a nonlinear projection of component membership variables, with a focus on powder bed additive manufacturing. For each component, constraints on the maximum allowable build volume (i.e., length, width, and height), the elimination of enclosed voids, and the minimum printable feature size are imposed during the simultaneous optimization of the overall base topology and component partitioning. The scalability of the new MTO formulation is demonstrated by a few 2D examples with much higher resolution than previously reported, and the first reported 3D example of MTO.

Redesigning a Reaction Control Thruster for Metal-Based Additive Manufacturing: A Case Study in Design for Additive Manufacturing

2016 ◽  
Author(s):  
Matthew R. Woods ◽  
Nicholas A. Meisel ◽  
Timothy W. Simpson ◽  
Corey J. Dickman
Keyword(s):  
Additive Manufacturing ◽  
Attitude Control ◽  
Development Effort ◽  
Design For Additive Manufacturing ◽  
Powder Bed ◽  
Subtractive Manufacturing ◽  
End Use ◽  
Manufacturing Time ◽  
Novel Design

Prior research has shown that powder bed fusion additive manufacturing (AM) can be used to make functional, end-use components from powdered metallic alloys, such as Inconel® 718 super alloy. However, these end-use products are often based on designs developed for more traditional subtractive manufacturing processes without taking advantage of the unique design freedoms afforded by AM. In this paper, we present a case study involving the redesign of NASA’s existing “Pencil” thruster used for spacecraft attitude control. The initial “Pencil” thruster was designed for, and manufactured using, traditional subtractive methods. The main focus in this paper is to (a) review the Design for Additive Manufacturing (DfAM) concepts and considerations used in redesigning the thruster and (b) compare it with a parallel development effort redesigning the original thruster to be manufactured more effectively using subtractive processes. The results from this study show how developing end-use AM components using DfAM guidelines can significantly reduce manufacturing time and costs while introducing new and novel design geometries.

Lattice Structure Design for Additive Manufacturing: Unit Cell Topology Optimization

2019 ◽  
Author(s):  
Bradley Hanks ◽  
Mary Frecker
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Lattice Structure ◽  
Optimization Method ◽  
Structure Design ◽  
Unit Cell ◽  
Lattice Structures ◽  
Design For Additive Manufacturing ◽  
Structure Topology

Abstract Additive manufacturing is a developing technology that enhances design freedom at multiple length scales, from the macroscale, or bulk geometry, to the mesoscale, such as lattice structures, and even down to tailored microstructure. At the mesoscale, lattice structures are often used to replace solid sections of material and are typically patterned after generic topologies. The mechanical properties and performance of generic unit cell topologies are being explored by many researchers but there is a lack of development of custom lattice structures, optimized for their application, with considerations for design for additive manufacturing. This work proposes a ground structure topology optimization method for systematic unit cell optimization. Two case studies are presented to demonstrate the approach. Case Study 1 results in a range of unit cell designs that transition from maximum thermal conductivity to minimization of compliance. Case Study 2 shows the opportunity for constitutive matching of the bulk lattice properties to a target constitutive matrix. Future work will include validation of unit cell modeling, testing of optimized solutions, and further development of the approach through expansion to 3D and refinement of objective, penalty, and constraint functions.

scholarly journals Optimization of Brake Calipers Using Topology Optimization for Additive Manufacturing

2021 ◽  
Vol 11 (4) ◽  
pp. 1437
Author(s):  
Evangelos Tyflopoulos ◽  
Mathias Lien ◽  
Martin Steinert
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Optimization Procedure ◽  
Optimization Approach ◽  
Design Flexibility ◽  
Current State ◽  
3D Printed ◽  
Removal Processes ◽  
Material Layout

The weight optimization of a structure can be conducted by using fewer and downsized components, applying lighter materials in production, and removing unwanted material. Topology optimization (TO) is one of the most implemented material removal processes. In addition, when it is oriented towards additive manufacturing (AM), it increases design flexibility. The traditional optimization approach is the compliance optimization, where the material layout of a structure is optimized by minimizing its overall compliance. However, TO, in its current state of the art, is mainly used for design inspiration and not for manufacturing due to design complexities and lack of accuracy of its design solutions. The authors, in this research paper, explore the benefits and the limitations of the TO using as a case study the housings of a front and a rear brake caliper. The calipers were optimized for weight reduction by implementing the aforementioned optimization procedure. Their housings were topologically optimized, partially redesigned, prepared for 3D printing, validated, and 3D printed in titanium using selective laser melting (SLM). The weight of the optimized calipers reduced by 41.6% compared to commercial calipers. Designers interested in either TO or in automotive engineering can exploit the findings in this paper.

scholarly journals Probabilistic Modelling of Defects in Additive Manufacturing: A Case Study in Powder Bed Fusion Technology

Procedia CIRP ◽  
2019 ◽  
Vol 81 ◽  
pp. 956-961 ◽  
Author(s):  
Hossein Mokhtarian ◽  
Azarakhsh Hamedi ◽  
Hari P.N. Nagarajan ◽  
Suraj Panicker ◽  
Eric Coatanéa ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Probabilistic Modelling ◽  
Powder Bed Fusion ◽  
Fusion Technology ◽  
Powder Bed

Redesigning a Reaction Control Thruster for Metal-Based Additive Manufacturing: A Case Study in Design for Additive Manufacturing

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Nicholas A. Meisel ◽  
Matthew R. Woods ◽  
Timothy W. Simpson ◽  
Corey J. Dickman
Keyword(s):  
Additive Manufacturing ◽  
Attitude Control ◽  
Manufacturing Processes ◽  
Development Effort ◽  
Design For Additive Manufacturing ◽  
Powder Bed ◽  
Subtractive Manufacturing ◽  
End Use ◽  
Manufacturing Time

Prior research has shown that powder-bed fusion (PBF) additive manufacturing (AM) can be used to make functional, end-use components from powdered metallic alloys, such as Inconel® 718 superalloy. However, these end-use components and products are often based on designs developed for more traditional subtractive manufacturing processes and do not take advantage of the unique design freedoms afforded by AM. In this paper, we present a case study involving the redesign of NASA’s existing “pencil” thruster used for spacecraft attitude control. The initial pencil thruster was designed for and manufactured using traditional subtractive methods. The main focus in this paper is to (a) identify the need for and use of both opportunistic and restrictive design for additive manufacturing (DfAM) concepts and considerations in redesigning the thruster for fabrication with PBF AM and (b) compare the resulting DfAM thruster with a parallel development effort redesigning the original thruster to be manufactured more effectively using subtractive manufacturing processes. The results from this case study show how developing end-use AM components using specific DfAM guidelines can significantly reduce manufacturing time and costs while enabling new and novel design geometries.

(Re)Designing for Part Consolidation: Understanding the Challenges of Metal Additive Manufacturing

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
John Schmelzle ◽  
Eric V. Kline ◽  
Corey J. Dickman ◽  
Edward W. Reutzel ◽  
Griffin Jones ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
System Level ◽  
Powder Bed ◽  
Part Consolidation ◽  
Case Part ◽  
Metallic Parts ◽  
Design Freedom ◽  
Am Processes ◽  
Metal Additive

Additive manufacturing (AM) of metallic parts provides engineers with unprecedented design freedom. This enables designers to consolidate assemblies, lightweight designs, create intricate internal geometries for enhanced fluid flow or heat transfer performance, and fabricate complex components that previously could not be manufactured. While these design benefits may come “free” in many cases, it necessitates an understanding of the limitations and capabilities of the specific AM process used for production, the system-level design intent, and the postprocessing and inspection/qualification implications. Unfortunately, design for additive manufacturing (DfAM) guidelines for metal AM processes are nascent given the rapid advancements in metal AM technology recently. In this paper, we present a case study to provide insight into the challenges that engineers face when redesigning a multicomponent assembly into a single component fabricated using laser-based powder bed fusion for metal AM. In this case, part consolidation is used to reduce the weight by 60% and height by 53% of a multipart assembly while improving performance and minimizing leak points. Fabrication, postprocessing, and inspection issues are also discussed along with the implications on design. A generalized design approach for consolidating parts is presented to help designers realize the freedoms that metal AM provides, and numerous areas for investigation to improve DfAM are also highlighted and illustrated throughout the case study.

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