Investigation of Parameter Spaces for Topology Optimization With Three-Dimensional Orientation Fields for Multi-Axis Additive Manufacturing

2020 ◽  
Vol 143 (5) ◽  
Author(s):  
Joseph R. Kubalak ◽  
Alfred L. Wicks ◽  
Christopher B. Williams
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Design Space ◽  
Mechanical Performance ◽  
Unit Length ◽  
Three Dimensions ◽  
Layer By Layer ◽  
Material Distribution ◽  
Orientation Fields ◽  
Material Orientation

Abstract The layer-by-layer deposition process used in material extrusion (ME) additive manufacturing results in inter- and intra-layer bonds that reduce the mechanical performance of printed parts. Multi-axis (MA) ME techniques have shown potential for mitigating this issue by enabling tailored deposition directions based on loading conditions in three dimensions (3D). Planning deposition paths leveraging this capability remains a challenge, as an intelligent method for assigning these directions does not exist. Existing literature has introduced topology optimization (TO) methods that assign material orientations to discrete regions of a part by simultaneously optimizing material distribution and orientation. These methods are insufficient for MA–ME, as the process offers additional freedom in varying material orientation that is not accounted for in the orientation parameterizations used in those methods. Additionally, optimizing orientation design spaces is challenging due to their non-convexity, and this issue is amplified with increased flexibility; the chosen orientation parameterization heavily impacts the algorithm’s performance. Therefore, the authors (i) present a TO method to simultaneously optimize material distribution and orientation with considerations for 3D material orientation variation and (ii) establish a suitable parameterization of the orientation design space. Three parameterizations are explored in this work: Euler angles, explicit quaternions, and natural quaternions. The parameterizations are compared using two benchmark minimum compliance problems, a 2.5D Messerschmitt–Bölkow–Blohm beam and a 3D Wheel, and a multi-loaded structure undergoing (i) pure tension and (ii) three-point bending. For the Wheel, the presented algorithm demonstrated a 38% improvement in compliance over an algorithm that only allowed planar orientation variation. Additionally, natural quaternions maintain the well-shaped design space of explicit quaternions without the need for unit length constraints, which lowers computational costs. Finally, the authors present a path toward integrating optimized geometries and material orientation fields resulting from the presented algorithm with MA–ME processes.

scholarly journals A Shape Optimization Method for Part Design Derived from the Buildability Restrictions of the Directed Energy Deposition Additive Manufacturing Process

Designs ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 19
Author(s):  
Andreas K. Lianos ◽  
Harry Bikas ◽  
Panagiotis Stavropoulos
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Energy Deposition ◽  
Design Method ◽  
Current Trend ◽  
Internal Stresses ◽  
Material Distribution ◽  
Load Case ◽  
Design Elements ◽  
Industrial Sectors

The design methodologies and part shape algorithms for additive manufacturing (AM) are rapidly growing fields, proven to be of critical importance for the uptake of additive manufacturing of parts with enhanced performance in all major industrial sectors. The current trend for part design is a computationally driven approach where the parts are algorithmically morphed to meet the functional requirements with optimized performance in terms of material distribution. However, the manufacturability restrictions of AM processes are not considered at the primary design phases but at a later post-morphed stage of the part’s design. This paper proposes an AM design method to ensure: (1) optimized material distribution based on the load case and (2) the part’s manufacturability. The buildability restrictions from the direct energy deposition (DED) AM technology were used as input to the AM shaping algorithm to grant high AM manufacturability. The first step of this work was to define the term of AM manufacturability, its effect on AM production, and to propose a framework to estimate the quantified value of AM manufacturability for the given part design. Moreover, an AM design method is proposed, based on the developed internal stresses of the build volume for the load case. Stress tensors are used for the determination of the build orientation and as input for the part morphing. A top-down mesoscale geometric optimization is used to realize the AM part design. The DED Design for Additive Manufacturing (DfAM) rules are used to delimitate the morphing of the part, representing at the same time the freeform mindset of the AM technology. The morphed shape of the part is optimized in terms of topology and AM manufacturability. The topology optimization and AM manufacturability indicator (TMI) is introduced to screen the percentage of design elements that serve topology optimization and the ones that serve AM manufacturability. In the end, a case study for proof of concept is realized.

Scalable submicrometer additive manufacturing

Science ◽  
2019 ◽  
Vol 366 (6461) ◽  
pp. 105-109 ◽  
Author(s):  
Sourabh K. Saha ◽  
Dien Wang ◽  
Vu H. Nguyen ◽  
Yina Chang ◽  
James S. Oakdale ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Design Space ◽  
Three Dimensional ◽  
Complex Structures ◽  
Layer By Layer ◽  
Promising Candidate ◽  
Single Digit ◽  
Cross Sectional ◽  
Two Photon ◽  
Nanoscale Features

High-throughput fabrication techniques for generating arbitrarily complex three-dimensional structures with nanoscale features are desirable across a broad range of applications. Two-photon lithography (TPL)–based submicrometer additive manufacturing is a promising candidate to fill this gap. However, the serial point-by-point writing scheme of TPL is too slow for many applications. Attempts at parallelization either do not have submicrometer resolution or cannot pattern complex structures. We overcome these difficulties by spatially and temporally focusing an ultrafast laser to implement a projection-based layer-by-layer parallelization. This increases the throughput up to three orders of magnitude and expands the geometric design space. We demonstrate this by printing, within single-digit millisecond time scales, nanowires with widths smaller than 175 nanometers over an area one million times larger than the cross-sectional area.

scholarly journals Taking into account thermal residual stresses in topology optimization of structures built by additive manufacturing

2018 ◽  
Vol 28 (12) ◽  
pp. 2313-2366 ◽  
Author(s):  
Grégoire Allaire ◽  
Lukas Jakabčin
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Residual Stresses ◽  
Heat Fluxes ◽  
Powder Layer ◽  
Layer By Layer ◽  
Thermal Deformations ◽  
Thermal Residual Stresses ◽  
Structural Design Optimization ◽  
Manufacturing Techniques

We introduce a model and several constraints for shape and topology optimization of structures, built by additive manufacturing techniques. The goal of these constraints is to take into account the thermal residual stresses or the thermal deformations, generated by processes like Selective Laser Melting, right from the beginning of the structural design optimization. In other words, the structure is optimized concurrently for its final use and for its behavior during the layer-by-layer production process. It is well known that metallic additive manufacturing generates very high temperatures and heat fluxes, which in turn yield thermal deformations that may prevent the coating of a new powder layer, or thermal residual stresses that may hinder the mechanical properties of the final design. Our proposed constraints are targeted to avoid these undesired effects. Shape derivatives are computed by an adjoint method and are incorporated into a level set numerical optimization algorithm. Several 2D and 3D numerical examples demonstrate the interest and effectiveness of our approach.

Topology and Free Size Optimization With Manufacturing Constraints for Light Weight Die Cast Automotive Backrest Frame

2009 ◽  
Author(s):  
Sreeram Polavarapu ◽  
Lonny L. Thompson ◽  
Mica Grujicic
Keyword(s):  
Finite Element ◽  
Topology Optimization ◽  
Design Space ◽  
Size Optimization ◽  
Manufacturing Constraints ◽  
Material Distribution ◽  
Front Seat ◽  
Die Cast ◽  
Stiffening Ribs ◽  
Multiple Load

Finite element analysis, together with topology and free-size optimization is used to design a lightweight die cast automotive front seat backrest frame when subjected to loads prescribed by ECE R17 European government regulations and additional loads which are predicted in an event of crash. In particular, an effort is made here to study the characteristics of a die cast automotive front seat backrest frame and develop a method for predicting the optimized material and support rib distribution which provides a lightweight seat which satisfies both strength and deflection requirements in a design space which includes the action of multiple load cases. An existing commercially available die cast backrest frame serves as the reference design space. Both 3D surface and solid models are created for representation as shell and solid finite element models for analysis. The objective function for topology optimization of the 3D solid model is to minimize mass of the component subject to stress and deflection constraints and is used as a guide in determining optimal geometric distribution of stiffening ribs. When the shell model of the reference seat is subjected to free-size optimization with this same constraint and objective given, an optimized material distribution measured by shell element thicknesses is obtained. For the topology optimization, manufacturing constraints of preferred draw direction and symmetry are applied in order to obtain an optimized material distribution which can be manufactured in the die-cast process. The procedure followed in this work generated an optimal material distribution and stiffening ribs in a lightweight die cast automotive seat backrest frame when subjected to multiple load cases. An overall reduction in weight of 13% is achieved over a reference commercially available die cast backrest frame component.

scholarly journals The quest for stiff, strong and tough hybrid materials: an exhaustive exploration

2013 ◽  
Vol 10 (89) ◽  
pp. 20130711 ◽  
Author(s):  
F. Barthelat ◽  
M. Mirkhalaf
Keyword(s):  
Topology Optimization ◽  
Spider Silk ◽  
Design Space ◽  
Materials Science ◽  
Mechanical Performance ◽  
Soft Materials ◽  
Global Approach ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Global Optima

How to arrange soft materials with strong but brittle reinforcements to achieve attractive combinations of stiffness, strength and toughness is an ongoing and fascinating question in engineering and biological materials science. Recent advances in topology optimization and bioinspiration have brought interesting answers to this question, but they provide only small windows into the vast design space associated with this problem. Here, we take a more global approach in which we assess the mechanical performance of thousands of possible microstructures. This exhaustive exploration gives a global picture of structure–property relationships and guarantees that global optima can be found. Landscapes of optimum solutions for different combinations of desired properties can also be created, revealing the robustness of each of the solutions. Interestingly, while some of the major hybrid designs used in engineering are absent from the set of solutions, the microstructures emerging from this process are reminiscent of materials, such as bone, nacre or spider silk.

scholarly journals Micro Metal Additive Manufactured Low-Loss Slotted Rectangular Waveguides Operating at 220-500 GHz

2021 ◽  
Vol 9 ◽  
Author(s):  
Zixian Wu ◽  
Guanghua Shi ◽  
Yang Yu ◽  
Xiaozhu Wen ◽  
Cheng Guo ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Insertion Loss ◽  
Unit Length ◽  
Measurement Techniques ◽  
Layer By Layer ◽  
Low Loss ◽  
Additive Manufacturing Technology ◽  
Measurement Results ◽  
Rectangular Waveguides ◽  
Metal Additive

This paper reports the design, fabrication and measurement techniques for a set of low-loss slotted waveguides. The waveguides are fabricated based on a micro metal additive manufacturing technology. They were fabricated layer by layer in one piece without the need of post-fabrication assembly. As examples, straight waveguides in WR-3.4 (220-330°GHz) and WR-2.2 (330-500°GHz) bands were fabricated and tested. Measurement results show the insertion loss per unit length is 0.0615-0.122°dB/mm and 0.116-0.281°dB/mm, respectively.

Additive Manufacturing of Kevlar Reinforced Epoxy Composites

2019 ◽  
Author(s):  
Nashat Nawafleh ◽  
Jordan Chabot ◽  
Mutabe Aljaghtham ◽  
Cagri Oztan ◽  
Edward Dauer ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Mechanical Performance ◽  
Failure Strain ◽  
Flexural Modulus ◽  
Layer By Layer ◽  
Structural Components ◽  
Thermoset Composites ◽  
3D Objects ◽  
Layer Deposition ◽  
Subtractive Manufacturing

Abstract Additive manufacturing is defined as layer-by-layer deposition of materials on a surface to fabricate 3D objects with reduction in waste, unlike subtractive manufacturing processes. Short, flexible Kevlar fibers have been used in numerous studies to alter mechanical performance of structural components but never investigated within printed thermoset composites. This study investigates the effects of adding short Kevlar fibers on mechanical performance of epoxy thermoset composites and demonstrates that the addition of Kevlar by 5% in weight significantly improves flexure strength, flexural modulus, and failure strain by approximately 49%, 19%, and 38%, respectively. Hierarchical microstructures were imaged using scanning electron microscopy to observe the artefacts such as porosity, infill and material interdiffusion, which are inherent drawbacks of the 3D printing process.

Topology Optimization for Additive Manufacturing Considering Layer-Based Minimum Feature Sizes

2017 ◽  
Author(s):  
Mikhail Osanov ◽  
James K. Guest
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Manufacturing Process ◽  
Three Dimensional ◽  
Design Tool ◽  
Geometric Constraints ◽  
Layer By Layer ◽  
Simple Modification ◽  
Complex Structural ◽  
Manufacturing Technologies

The rapid advance of additive manufacturing technologies has provided new opportunities for creating complex structural shapes. In order to fully exploit these opportunities, however, engineers must re-think the design process and leverage these new capabilities while respecting manufacturing constraints inherent in various processes. Topology optimization, as a free-from design tool, is a potentially powerful approach to addressing this design challenge provided the manufacturing process is properly accounted for. This work examines geometric constraints related to feature size and the layer-by-layer nature of the manufacturing process. A simple modification to the Heaviside Projection Method, an approach for naturally achieving geometric constraints in topology optimization, is proposed and demonstrated to have clear, understandable impact on three-dimensional optimized beam designs.

scholarly journals Knowledge Management for Topological Optimization Integration in Additive Manufacturing

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Nicolas Gardan
Keyword(s):  
Knowledge Management ◽  
Additive Manufacturing ◽  
Mechanical Performance ◽  
Functional Performance ◽  
Topological Optimization ◽  
Layer By Layer ◽  
Support Material ◽  
Manufacturing Costs ◽  
Material Volume ◽  
Globalized World

Engineering design optimization of mechanical structures is nowadays essential in the mechanical industry (automotive, aeronautics, etc.). To remain competitive in the globalized world, it is necessary to create and design structures that, in addition to complying specific mechanical performance, should be less expensive. Engineers must then design parts or assemblies that are a better compromise between mechanical and functional performance, weight, manufacturing costs, and so forth. In this context Additive Manufacturing (AM) process offers the possibility to avoid tools and manufacture directly the part. There are numerous technologies which are using different kind of material. For each of these, there are at least two materials: the production material and the support one. Support material is, in most cases, cleaned and becomes a manufacturing residue. Improving the material volume and the global mass of the product is an essential aim surrounding the integration of simulation in additive manufacturing process. Moreover, the layer-by-layer technology of additive manufacturing allows the design of innovative objects, and the use of topological optimization in this context can create a very interesting combination. The purpose of our paper is to present the knowledge management of an AM trade oriented tool which integrated the topological optimization of parts and internal patterns.

scholarly journals Additive manufacturing of polymer-based structures by extrusion technologies

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Alianna Maguire ◽  
Neethu Pottackal ◽  
M A S R Saadi ◽  
Muhammad M Rahman ◽  
Pulickel M Ajayan
Keyword(s):  
Additive Manufacturing ◽  
Composite Materials ◽  
High Performance ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Future Research ◽  
Layer By Layer ◽  
Structural Applications ◽  
Materials Used ◽  
Extrusion Printing

Abstract Extrusion-based additive manufacturing (AM) enables the fabrication of three-dimensional structures with intricate cellular architectures where the material is selectively dispensed through a nozzle or orifice in a layer-by-layer fashion at the macro-, meso-, and micro-scale. Polymers and their composites are one of the most widely used materials and are of great interest in the field of AM due to their vast potential for various applications, especially for the medical, military, aerospace, and automotive industries. Because architected polymer-based structures impart remarkably improved material properties such as low density and high mechanical performance compared to their bulk counterparts, this review focuses particularly on the development of such objects by extrusion-based AM intended for structural applications. This review introduces the extrusion-based AM techniques followed by a discussion on the wide variety of materials used for extrusion printing, various architected structures, and their mechanical properties. Notable advances in newly developed polymer and composite materials and their potential applications are summarized. Finally, perspectives and insights into future research of extrusion-based AM on developing high-performance ultra-light materials using polymers and their composite materials are discussed.

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