Towards Integrating Topology Optimization and Additive Manufacturing
Towards Integrating Topology Optimization and Additive Manufacturing

Author: Amir M. Mirzendehdel

Publisher:

Published: 2017

Total Pages: 120

ISBN-13:

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Topology optimization (TO) is an automated design tool that integrates mathematical modeling with numerical analysis to automatically reduce weight and material usage while ensuring certain prescribed constraints on performance of the design are satisfied. The high-performance light-weight designs created through topology optimization are often free-form and organic, manufacturing of which through traditional casting, forming, or subtractive technologies can become quite challenging. Additive manufacturing (AM) is a class of more modern technologies that seem to alleviate this issue by fabricating complex parts layer by layer. On the other hand, the cost of additively manufactured parts increase significantly with material usage. Therefore, optimizing designs can reduce material usage, build time, and post-process time to make AM worthwhile. Thus, TO and AM complement each other to fabricate ever more complex high performance and customized yet affordable products. However, for these technologies to be integrated, there are certain issues, such as extraneous support structures or material anisotropy, that need to be considered within the optimization. Focus of this thesis is mainly on: 1. Addressing challenges on reducing amount of support structure and considering process-induced anisotropy throughout the optimization process. 2. Exploiting the capabilities of AM in free-form fabrication to improve performance by generating more complex multi-material designs. In other words, the present thesis attempts to make advances on integrating the two modern and promising fields, topology optimization and additive manufacturing by developing optimization algorithms that generate optimized designs while tracing Pareto frontiers. Perhaps the most important benefit of this class of methods is the fact that intermediate topologies remain structurally valid, thus iterative solvers can converge much faster. Further, these intermediate designs are local optimum solutions. These traits make these methods well-suited for rapidly exploring the design space to find freeform designs while ensuring their structural integrity.

Towards Design Automation for Additive Manufacturing
Towards Design Automation for Additive Manufacturing

Author: Anton Wiberg

Publisher: Linköping University Electronic Press

Published: 2019-10-14

Total Pages: 53

ISBN-13: 9179299857

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In recent decades, the development of computer-controlled manufacturing by adding materiallayer by layer, called Additive Manufacturing (AM), has developed at a rapid pace. The technologyadds possibilities to the manufacturing of geometries that are not possible, or at leastnot economically feasible, to manufacture by more conventional manufacturing methods. AMcomes with the idea that complexity is free, meaning that complex geometries are as expensiveto manufacture as simple geometries. This is partly true, but there remain several design rulesthat needs to be considered before manufacturing. The research field Design for Additive Manufacturing(DfAM) consists of research that aims to take advantage of the possibilities of AMwhile considering the limitations of the technique. Computer Aided technologies (CAx) is the name of the usage of methods and software thataim to support a digital product development process. CAx includes software and methodsfor design, the evaluation of designs, manufacturing support, and other things. The commongoal with all CAx disciplines is to achieve better products at a lower cost and with a shorterdevelopment time. The work presented in this thesis bridges DfAM with CAx with the aim of achieving designautomation for AM. The work reviews the current DfAM process and proposes a new integratedDfAM process that considers the functionality and manufacturing of components. Selectedparts of the proposed process are implemented in a case study in order to evaluate theproposed process. In addition, a tool that supports part of the design process is developed. The proposed design process implements Multidisciplinary Design Optimization (MDO) witha parametric CAD model that is evaluated from functional and manufacturing perspectives. Inthe implementation, a structural component is designed using the MDO framework, which includesComputer Aided Engineering (CAE) models for structural evaluation, the calculation ofweight, and how much support material that needs to be added during manufacturing. Thecomponent is optimized for the reduction of weight and minimization of support material,while the stress levels in the component are constrained. The developed tool uses methodsfor high level Parametric CAD modelling to simplify the creation of parametric CAD modelsbased on Topology Optimization (TO) results. The work concludes that the implementation of CAx technologies in the DfAM process enablesa more automated design process with less manual design iterations than traditional DfAM processes.It also discusses and presents directions for further research to achieve a fully automateddesign process for Additive Manufacturing.

Integrated Topology Optimization Design and Process Planning for Additive Manufacturing
Integrated Topology Optimization Design and Process Planning for Additive Manufacturing

Author: Dylan J. Bender

Publisher:

Published: 2019

Total Pages: 0

ISBN-13:

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Industry 4.0 demands that the systems and processes in today's product design and manufacturing not just be automated, but to be robust and containing many feedback mechanisms which enables it to be self-correcting. The hypothetical upcoming Industry 5.0 promises on demand and personalized products which this thesis aims to take a step in the direction of. It is proposed that an integrated and optimized process for structural topology optimization and subsequent additive manufacturing is possible for automated design and manufacturing starting from its problem definition. An improvement on the benchmarked topology optimization methods is shown which allows the user control over the optimization's convergence characteristics which is then further studied to find a robust set of optimization parameters. The resulting topology of the structure is then analyzed for its optimal printing orientation based on a custom-made algorithm which minimizes manufacturing costs. Furthermore, the structure is then sliced for instruction generation of layer-based manufacturing techniques in a novel fashion which also serves to provide feedback of the manufacturing process planning to the topology optimization design stage.

Algorithm-Driven Truss Topology Optimization for Additive Manufacturing
Algorithm-Driven Truss Topology Optimization for Additive Manufacturing

Author: Christian Reintjes

Publisher: Springer Nature

Published: 2022-02-01

Total Pages: 219

ISBN-13: 3658362111

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Since Additive Manufacturing (AM) techniques allow the manufacture of complex-shaped structures the combination of lightweight construction, topology optimization, and AM is of significant interest. Besides the established continuum topology optimization methods, less attention is paid to algorithm-driven optimization based on linear optimization, which can also be used for topology optimization of truss-like structures. To overcome this shortcoming, we combined linear optimization, Computer-Aided Design (CAD), numerical shape optimization, and numerical simulation into an algorithm-driven product design process for additively manufactured truss-like structures. With our Ansys SpaceClaim add-in construcTOR, which is capable of obtaining ready-for-machine-interpretation CAD data of truss-like structures out of raw mathematical optimization data, the high performance of (heuristic-based) optimization algorithms implemented in linear programming software is now available to the CAD community.

Topology Optimization Subject to Additive Manufacturing Constraints
Topology Optimization Subject to Additive Manufacturing Constraints

Author: Moritz Ebeling-Rump

Publisher:

Published: 2019

Total Pages: 228

ISBN-13:

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In Topology Optimization the goal is to find the ideal material distribution in a domain subject to external forces. The structure is optimal if it has the highest possible stiffness. A volume constraint ensures filigree structures, which are regulated via a Ginzburg-Landau term. During 3D Printing overhangs lead to instabilities, which have only been tackled unsatisfactorily. The novel idea is to incorporate an Additive Manufacturing Constraint into the phase field method. A rigorous analysis proves the existence of a solution and leads to first order necessary optimality conditions. With an Allen-Cahn interface propagation the optimization problem is solved iteratively. At a low computational cost the Additive Manufacturing Constraint brings about support structures, which can be fine tuned according to engineering demands. Stability during 3D Printing is assured, which solves a common Additive Manufacturing problem.

Topology Optimization for Additive Manufacturing Involving High-Cycle Fatigue
Topology Optimization for Additive Manufacturing Involving High-Cycle Fatigue

Author: Shyam Suresh

Publisher: Linköping University Electronic Press

Published: 2020-05-05

Total Pages: 41

ISBN-13: 9179298508

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Additive Manufacturing (AM) is gaining popularity in aerospace and automotive industries. This is a versatile manufacturing process, where highly complex structures are fabricated and together with topology optimization, a powerful design tool, it shares the property of providing a very large freedom in geometrical form. The main focus of this work is to introduce new developments of Topology Optimization (TO) for metal AM. The thesis consists of two parts. The first part introduces background and theory, where TO and adjoint sensitivity analysis are described. Furthermore, methodology used to identify surface layer and high-cycle fatigue are introduced. In the second part, three papers are appended, where the first paper presents the treatment of surface layer effects, while the second and third papers provide high-cycle fatigue constraint formulations. In Paper I, a TO method is introduced to account for surface layer effects, where different material properties are assigned to bulk and surface regions. In metal AM, the fabricated components in as-built surface conditions significantly affect mechanical properties, particularly fatigue properties. Furthermore, the components are generally in-homogeneous and have different microstructures in bulk regions compared to surface regions. We implement two density filters to account for surface effects, where the width of the surface layer is controlled by the second filter radius. 2-D and 3-D numerical examples are treated, where the structural stiffness is maximized for a limited mass. For Papers II and III, a high-cycle fatigue constraint is implemented in TO. A continuous-time approach is used to predict fatigue-damage. The model uses a moving endurance surface and the development of damage occurs only if the stress state lies outside the endurance surface. The model is applicable not only for isotropic materials (Paper II) but also for transversely isotropic material properties (Paper III). It is capable of handling arbitrary load histories, including non-proportional loads. The anisotropic model is applicable for additive manufacturing processes, where transverse isotropic properties are manifested not only in constitutive elastic response but also in fatigue properties. Two optimization problems are solved: In the first problem the structural mass is minimized subject to a fatigue constraint while the second problem deals with stiffness maximization subjected to a fatigue constraint and mass constraint. Several numerical examples are tested with arbitrary load histories.

Topology Design Methods for Structural Optimization
Topology Design Methods for Structural Optimization

Author: Osvaldo M. Querin

Publisher: Butterworth-Heinemann

Published: 2017-06-09

Total Pages: 205

ISBN-13: 0080999891

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Topology Design Methods for Structural Optimization provides engineers with a basic set of design tools for the development of 2D and 3D structures subjected to single and multi-load cases and experiencing linear elastic conditions. Written by an expert team who has collaborated over the past decade to develop the methods presented, the book discusses essential theories with clear guidelines on how to use them. Case studies and worked industry examples are included throughout to illustrate practical applications of topology design tools to achieve innovative structural solutions. The text is intended for professionals who are interested in using the tools provided, but does not require in-depth theoretical knowledge. It is ideal for researchers who want to expand the methods presented to new applications, and includes a companion website with related tools to assist in further study. Provides design tools and methods for innovative structural design, focusing on the essential theory Includes case studies and real-life examples to illustrate practical application, challenges, and solutions Features accompanying software on a companion website to allow users to get up and running fast with the methods introduced Includes input from an expert team who has collaborated over the past decade to develop the methods presented

Topology Optimization in Engineering Structure Design
Topology Optimization in Engineering Structure Design

Author: Jihong Zhu

Publisher: Elsevier

Published: 2016-11-08

Total Pages: 296

ISBN-13: 0081021194

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Topology Optimization in Engineering Structure Design explores the recent advances and applications of topology optimization in engineering structures design, with a particular focus on aircraft and aerospace structural systems.To meet the increasingly complex engineering challenges provided by rapid developments in these industries, structural optimization techniques have developed in conjunction with them over the past two decades. The latest methods and theories to improve mechanical performances and save structural weight under static, dynamic and thermal loads are summarized and explained in detail here, in addition to potential applications of topology optimization techniques such as shape preserving design, smart structure design and additive manufacturing.These new design strategies are illustrated by a host of worked examples, which are inspired by real engineering situations, some of which have been applied to practical structure design with significant effects. Written from a forward-looking applied engineering perspective, the authors not only summarize the latest developments in this field of structure design but also provide both theoretical knowledge and a practical guideline. This book should appeal to graduate students, researchers and engineers, in detailing how to use topology optimization methods to improve product design. Combines practical applications and topology optimization methodologies Provides problems inspired by real engineering difficulties Designed to help researchers in universities acquire more engineering requirements

Using Topology Optimization to Improve Design for Additive Manufacture
Using Topology Optimization to Improve Design for Additive Manufacture

Author: Ian Ferguson

Publisher:

Published: 2015

Total Pages:

ISBN-13:

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Additive manufacturing (AM) offers new design freedom to create topologies with complex surfaces and internal structures that could not be produced by traditional manufacturing processes. Due to this design flexibility, parts designed for AM have the potential to withstand the same structural loads as traditionally manufactured parts at lower masses. In an attempt to reduce the mass of structural parts to a minimum, optimization techniques such as topology optimization can be employed to achieve geometries that may be unintuitive to designers. While in many cases AM is the only means to realize such an optimized design, the constraints of the particular AM process may require a design to be modified before it can be produced. This thesis examines the current state of topology optimization technology and investigates how topology optimization software fits into the workflow of design for AM. This is achieved by exploring the problem of minimizing the mass of a mounting plate for an aerospace vehicle. Optimization is performed with varying boundary conditions and materials to observe their effect on resulting topologies and design performance. The results are then manually interpreted to conform to AM constraints. A 60% weight savings was achieved over the current mounting plate design, but the optimization software did not take AM constraints into account. Manual design modifications were required to ensure that the design was one continuous part and that a suitable prototype of the optimized design could be produced. In the context of this problem, the benefits and limitations of incorporating topology optimization into design for AM are presented. It was found that manual design workflow for AM requires the designer to iterate design around performance, while incorporating topology optimization into the workflow requires the designer to iterate design around manufacturability.

Multiscale Structural Topology Optimization
Multiscale Structural Topology Optimization

Author: Liang Xia

Publisher: Elsevier

Published: 2016-04-27

Total Pages: 186

ISBN-13: 0081011865

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Multiscale Structural Topology Optimization discusses the development of a multiscale design framework for topology optimization of multiscale nonlinear structures. With the intention to alleviate the heavy computational burden of the design framework, the authors present a POD-based adaptive surrogate model for the RVE solutions at the microscopic scale and make a step further towards the design of multiscale elastoviscoplastic structures. Various optimization methods for structural size, shape, and topology designs have been developed and widely employed in engineering applications. Topology optimization has been recognized as one of the most effective tools for least weight and performance design, especially in aeronautics and aerospace engineering. This book focuses on the simultaneous design of both macroscopic structure and microscopic materials. In this model, the material microstructures are optimized in response to the macroscopic solution, which results in the nonlinearity of the equilibrium problem of the interface of the two scales. The authors include a reduce database model from a set of numerical experiments in the space of effective strain. Presents the first attempts towards topology optimization design of nonlinear highly heterogeneous structures Helps with simultaneous design of the topologies of both macroscopic structure and microscopic materials Helps with development of computer codes for the designs of nonlinear structures and of materials with extreme constitutive properties Focuses on the simultaneous design of both macroscopic structure and microscopic materials Includes a reduce database model from a set of numerical experiments in the space of effective strain