Browsing by Subject "topology optimization"
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Item Application of Topology Optimization in Modern Additive Manufacturing(University of Texas at Austin, 2010) Chahine, Gilbert; Smith, Pauline; Kovacevic, RadovanThe current work examines the principle of topology optimization (TOP) and solving the problem of minimal compliance, and its applications in modern additive manufacturing (AM). The theory of TOP has been excessively investigated for the past few decades; however its practical use is hindered by manufacturing limitations of manifesting the designs into physical parts. TOP numerically determines the favorable topology configuration contained in a workspace that is constrained by a specific set of external supports and applied loads. It overcomes conventional design traditions, and solves for finding the path of least resistance, mimicking phenomenon found in natural structures, such as bone and wood. The present research focuses on the different methodologies invested in the field, and also inspects the possibilities and efficiency of using numerical design, which is powered by TOP, in modern AM processes such as Electron Beam Melting enabling the production of highly complex parts. The major interest is the production of functionally graded porosity (FGP) in bio-adaptable dental implants able to reduce stress shielding, promote faster osseointegration, and provide micromotion between the dental prosthesis and the root form of the implant. Future implications of the field include optimized porous structures aiming towards application-defined stiffness and pore size, enabling a digital design with advances analogous to modern AM.Item Beam Structure Optimization for Additive Manufacturing based on Principal Stress Lines(University of Texas at Austin, 2010-09-23) Li, Yongqiang; Chen, YongThe benefits of component design with cellular structures have been demonstrated in a wide variety of applications. The recent advances in additive manufacturing and high performance computing have enabled us to design a product component with adaptive cellular structures to achieve significantly better performance. However, designing a product component with such structures, especially its shape and topology, poses significant challenges. Many approaches in topology optimization have been developed before for the purpose. In this paper, we present a novel structural optimization method based on the principal stress line analysis of a continuum domain. We first present the theoretical basis of our optimization method. We then discuss the properties of principal stress lines and their computation in a given design domain. Accordingly a novel structural optimization method is presented including size, shape and topology optimization. Related mathematical formulations and algorithms are also given for generating a beam structure with the minimum compliance. Three test cases are presented to illustrate the presented method.Item Cellular and Topology Optimization of Beams under Bending: An Experimental Study(University of Texas at Austin, 2019) Gopal, Arjun; Parihar, Gaurav; Holt, McKay; Stinson, Tanner; Sharma, Manasvi; Bhate, DhruvDesign for Additive Manufacturing (AM) includes concepts such as cellular materials and topology optimization that combine the capabilities of advanced computational design with those of AM technologies that can realize them. There is however, limited experimental study of the relative benefits of these different approaches to design. This paper examines these two different approaches, specifically in the context of maximizing the flexural rigidity of a beam under bending, while minimizing its mass. A total of 23 beams were designed using commercially available cellular design, and topology optimization software. The Selective Laser Sintering (SLS) process was used to manufacture these beams with Nylon 12, which were then tested per ASTM D790 three-point bend test standards. The effect of varying the size and shape of cells on the flexural rigidity was studied using 15 different cellular designs. These results were then compared to six different topology optimized beam designs, as well as three solid and hollow baseline beams. These preliminary findings suggest that topology optimized shapes underperform their cellular counterparts with regard to specific stiffness, and that stochastic cellular shapes deserve deeper study.Item Design and Manufacture of a Continuous Fiber-Reinforced 3D Printed Unmanned Aerial Vehicle Win(University of Texas at Austin, 2021) Jayashankar, Dhileep Kumar; Devarajan, Aarthi; Dong, Guoying; Rosen, DavidThe Markforged Mark Two 3D printer is capable of printing various orientations of continuous fiber reinforcement. An initial study of how the orientation of the fiber influences the strength characteristics (tensile and flexural properties) was conducted. Four combinations of carbon fiber reinforcement orientations were tested, specifically unidirectional, isotropic, concentric and a combination of isotropic and concentric, with the Markforged Onyx matrix material. The results will aid in designing a wing with the optimum fiber configuration that will give the desired mechanical properties based on the forces acting on the wing. Design for Additive Manufacturing (DfAM) concepts and tools will be used to design and manufacture a large UAV wing. Topology optimization, based on a CFD computed pressure distribution, was used to determine geometric regions where carbon fiber reinforcement could be best utilized. From there, a honeycomb structure was designed to ensure stiffness and light weight based on desired densities. A wing section was fabricated using the Mark Two printer to identify the capabilities and limitations of the system in realizing the design objectives.Item Development, Production and Post-Processing of a Topology Optimized Aircraft Bracket(University of Texas at Austin, 2019) Klippstein, Helge; Duchting, Anne; Reiher, Thomas; Hengsbach, Florian; Menge, Dennis; Schmid, Hans-JoachimStructural parts for aviation have very high demands on the development and production process. Therefore, the entire process must be considered in order to produce high-quality AM metal parts. In this case study, a conventional part was selected to be optimized for AM. The process presented includes component selection, design improvement with a novel approach for topology optimization based on the AMendate algorithm as basis of MSC Apex Generative Design, component production on a SLM 250 HL and post-processing including heat treatment and surface smoothing. With the topology optimization a weight reduction of ~60 % could be realized, whereby the stress distribution is more homogeneous. Furthermore, the challenges of support optimization and post-processing have to be addressed, in order to produce competitive parts.Item Effect of Sparse-Build Internal Structure on Performance of Fused Deposition Modeling Tools Under Pressure(University of Texas at Austin, 2016) Meng, S.; Mason, L.; Taylor, G.; Wang, X.; Leu, M.C.; Chandrashekhara, K.Two different approaches to design a sparse-build tool for fabrication by the fused deposition modeling (FDM) process are compared. One approach uses a 2D lattice structure and the other approach is inspired by topology optimization. Ultem 9085 is used as the material, and the amount of material used to build the tool is kept constant to ensure a fair comparison. A solid tool is also included in the comparison. The performance of the tool under uniform pressure is simulated using finite element analysis (FEA) and the accuracy of the FEA results is verified by comparing them with experimentally measured data for a similar tool. The build material, support material, build time, maximum displacement, and maximum von Mises stress are compared for the three build approaches, with an emphasis on the pros and cons of each sparse-build tool with regards to performance under uniform pressure and fabrication by FDM.Item An Empirical Study Linking Additive Manufacturing Design Process to Success in Manufacturability(University of Texas at Austin, 2019) Mehta, Priyesh; Berdanier, Catherine G.P.; Malviya, Manoj; Miller, Colin; Manogharan, GuhaThis paper characterizes engineering designers’ abilities to re-design a component for additive manufacturing, employing screen capture methods. Additive Manufacturing has garnered significant interest from a wide range of industries, academia and government stakeholders due to its potential to reform and disrupt traditional manufacturing processes. The technology offers unprecedented design freedom and customization along with its ability to process novel and high strength alloys in promising lead times. To harness the maximum potential of this technology, designers are often tasked with creating new products or re-design existing portfolios of traditionally manufactured parts to achieve lightweight designs with better performance. To date, few studies explore the correspondence between design behaviors and manufacturability of final product within an Additive Manufacturing context. This paper presents empirical data from the design processes of six graduate student engineering designers as they re-design a traditionally designed part for additive manufacturing. Behaviors through the design task are compared between the study participants with a quantitative measure of the manufacturability and quality of each design. Results indicate opportunities for further research and best practices in design for Additive manufacturing and engineering education practitioners across multiple disciplines.Item An Experimental Study of Design Strategies for Stiffening Thin Plates under Compression(University of Texas at Austin, 2019) Ramirez Chavez, Irving E.; Noe, Cameron; Sekar, Vigneshwaran; Jogani, Shainil; Israni, Siddharth; Bhate, DhruvIncreasing stiffness and failure loads while minimizing mass is useful in many engineering applications, including the design of thin plates and shells. In this paper, the performance of thin plates using a range of stiffening approaches were studied for the specific instance of compressive loading. Periodic, graded, stepped, “Voronoi” stochastic, and topologically optimized patterns were explored. These stiffening designs were realized using different software tools and manufactured with the Selective Laser Sintering (SLS) process. These 3D printed specimens were tested under compression to assess their mechanical response. Videos of these tests were recorded to study the shape of the failure modes. This data was analyzed to determine the performance of the different stiffener designs, in comparison to the performance of baseline plates without any stiffening. The study concludes with a discussion of the results and their implications for stiffening thin plates, showing that triangular and stochastic stiffening strategies show particular promise in increasing specific compressive stiffness and specific buckling load.Item FE-Optimization and Data Handling for Additive Manufacturing of Structural Parts(University of Texas at Austin, 2015) Reiher, Thomas; Koch, RainerAdditive Manufacturing (AM) offers high potential due to its freedom of design for structural parts. Especially in combination with FE-based topology optimization an optimal use of material and thus significant weight reductions can be expected. However, the application of AM is hampered by different additional manufacturing processes along the entire production chain and data handling induced restrictions. Disadvantages emerge from a lack of adjustment of the entire design process for AM. First the optimization algorithms are not targeted to the opportunities and restrictions of AM – represented by design rules – like the design of support structures. Secondly, the CAD software is not adjusted to AM in particular. Creating freeform shaped surfaces based on the optimization results is significantly less convenient than building defined blocks or turning parts following the needs of conventional machining. The indispensable subsequent interpretation of optimization results regarding the design rules and the possibilities of CAD-tools counteracts optimal results. This paper considers different approaches for a Topology Optimization (TO)-shape regaining on different sample parts including telecommunication satellite parts. An innovative design methodology is presented getting crucial for creating high quality designs.Item GUIDED MANUAL DESIGN FOR ADDITIVE MANUFACTURING OF TOPOLOGICALLY OPTIMIZED LEGACY TOOLING PARTS(University of Texas at Austin, 2023) Luben, Hannah; Meisel, NicholasDesign for Additive Manufacturing (DfAM) is a unique conceptual way to adapt a part for Additive Manufacturing (AM). While some of the choices made in DfAM become second nature to seasoned AM designers, inexperienced designers may not know the nuances involved in what is still a developing manufacturing technology. Topology Optimization (TO) in particular tends to create organic shapes that may not be immediately conducive to printing through AM. This paper proposes a comprehensive workflow tool to guide a designer, regardless of their experience, through the decision-making process inherent to DfAM. The guide helps the designer manually edit a legacy tooling design into a topologically optimized part that is readily manufacturable through AM. Discussion of a relevant case study follows the outline of the design tool to exemplify its use.Item High Resolution Topology Design with Iso-XFEM(University of Texas at Austin, 2014) Abdi, M.; Ashcroft, I.; Wildman, R.Topology optimization, as a challenging aspect of structural optimization, has gained interest in recent years as a method of designing structures to take advantage of the design freedoms of advanced manufacturing techniques such as Additive Manufacturing (AM). The majority of topology optimization algorithms are integrated with the Finite Element Method (FEM) to enable the analysis of structures with complex geometry during the optimization process. However, due to the finite element-based nature of the subsequent topology optimized solutions, the design boundaries are dependent on the finite element mesh used and tend not to have the desired smoothness for direct fabrication. The topology optimized solutions may, therefore, need smoothing, reanalysing and shape optimization before they become manufacturable. In this study, an Extended Finite Element Method (X-FEM) is employed and integrated with an evolutionary structural optimization algorithm, aiming to avoid/decrease the post-processing required from topology optimization design to manufacture. Rather than using finite elements for boundary representation, an isoline/isosurface approach is used to capture the design boundary during the optimization process. The comparison of the X-FEM-based solutions with the FE-based ones for the topology optimization of test cases representing real industrial components indicates significant improvements in the solutions’ boundary representation as well as their structural performance.Item A Hybrid Algorithm for Topology Optimization of Additive Manufactured Structures(University of Texas at Austin, 2011-08-17) Aremu, A.; Ashcroft, I.; Wildman, R.; Hague, R.; Tuck, C.; Brackett, D.Most topology (TO) algorithms involve the penalization of intricate structural features to eliminate manufacturing difficulties. Since additive manufacturing is less dependent on manufacturing constraints, it becomes necessary to adapt these algorithms for AM. We propose a hybrid algorithm consisting of an adaptive meshing strategy (AMS) and a modified form of the bidirectional evolutionary structural optimization (BESO) method. By solving a standard cantilever problem, we show that the hybrid method offers improved performance over the standard BESO method. It is proposed that the new method is more suitable for optimizing structures for AM in a computational efficient manner.Item Integration of Topology Optimization with Efficient Design of Additive Manufactured Cellular Structures(University of Texas at Austin, 2015) Cheng, Lin; Zhang, Pu; Biyikli, Emre; Bai, Jiaxi; Pilz, Steve; To, Albert C.Cellular structures are promising candidates for additive manufacturing to design lightweight and complex parts to reduce material cost and enhance sustainability. In the paper, we focus on the integration of the topology optimization with the additive manufactured cellular structures. In order to take advantage of these two technologies for lightweight manufacturing, a totally new design and CAD method is developed to build up the bridge between the optimal density distribution and the cellular structure. First, a systematic theoretical and experimental framework is provided to obtain the mechanical properties of cellular structures with variable density profile. Second, a revised topology optimization algorithm is introduced to optimize arbitrary 3D models with given boundary conditions. In this process, the minimum compliance problem and allowable stress problem are considered to get the relative density distribution. Third, CAD methods are developed to obtain the function between the local relative density and the variable density of cellular structure. With the aid of the function, one can convert the density distribution to the cellular vertex radius distribution and build variable density cellular structures in the given parts. Finally, a real part named pillow bracket is designed by this process to illustrate the efficiency and reliability of the new method.Item A Mold Insert Case Study on Topology Optimized Design for Additive Manufacturing(University of Texas at Austin, 2019) Sinico, M.; Ranjan, R.; Moshiri, M.; Ayas, C.; Langelaar, M.; Witvrouw, A.; van Keulen, F.; Dewulf, W.The Additive Manufacturing (AM) of injection molding inserts has gained popularity during recent years primarily due to the reduced design-to-production time and form freedom offered by AM. In this paper, Topology Optimization (TO) is performed on a metallic mold insert which is to be produced by the Laser Powder Bed Fusion (LPBF) technique. First, a commercially available TO software is used, to minimize the mass of the component while ensuring adequate mechanical response under a prescribed loading condition. The commercial TO tool adopts geometry-based AM constraints and achieves a mass reduction of ~50 %. Furthermore, an in-house TO method has been developed which integrates a simplified AM process model within the standard TO algorithm for addressing the issue of local overheating during manufacturing. The two topology optimized designs are briefly compared, and the advantages of implementing manufacturing constraints into the TO algorithm are discussed.Item Morphable Components Topology Optimization for Additive Manufacturing(University of Texas at Austin, 2018) Xian, Y.; Rosen, D.W.This paper addresses two issues: 1. Topology optimization (TO) yields designs that may require support structures if additively manufactured, which increase material and clean-up costs. 2. Material anisotropy is induced during additive manufacturing, which results in inaccurate TO results if such material properties are not included in the algorithm. This paper, based on a moving morphable components (MMC) approach where structure is composed of several building blocks, introduces constraints for minimum build angle, as well as a penalty constraint for building blocks with no support material below, so that the TO output is completely printable. Additionally, orthotropic material properties are integrated in the optimization. In a separate optimization algorithm, each building block is assumed to have its own fiber orientation.Item Multi-Material Structural Topology Optimization Under Uncertainty via a Stochastic Reduced Order Model Approach(University of Texas at Austin, 2017) Aguiló, M.A.; Warner, J.E.This work presents a stochastic reduced order modeling approach for the solution of uncertainty aware, multi-material, structural topology optimization problems. Uncertainty aware structural topology optimization problems are computationally complex due to the number of model evaluations that are needed to quantify and propagate design uncertainties. This computational complexity is magnified if high-fidelity simulations are used during optimization. A stochastic reduced order model (SROM) approach is applied to 1) alleviate the prohibitive computational cost associated with large-scale, uncertainty aware, structural topology optimization problems; and 2) quantify and propagate inherent uncertainties due to design imperfections. The SROM framework transforms the uncertainty aware, multi-material, structural topology optimization problem into a deterministic optimization problem that relies only on independent calls to a deterministic analysis engine. This approach enables the use of existing optimization and analysis tools for the solution of uncertainty aware, multi-material, structural topology optimization problems.Item Multiple-Material Topology Optimization of Compliant Mechanisms Created via Polyjet 3D Printing(University of Texas at Austin, 2013) Meisel, Nicholas A.; Gaynor, Andrew; Williams, Christopher B.; Guest, James K.Compliant mechanisms are able to transfer motion, force, and energy using a monolithic structure without discrete hinge elements. The geometric design freedoms and multi-material capability offered by the PolyJet 3D printing process enables the fabrication of compliant mechanisms with optimized topology. The inclusion of multiple materials in the topology optimization process has the potential to eliminate the narrow, weak, hinge-like sections that are often present in single-material compliant mechanisms. In this paper, the authors propose a design and fabrication process for the realization of 3-phase, multiple-material compliant mechanisms. The process is tested on a 2D compliant force inverter. Experimental and theoretical performance of the resulting 3-phase inverter is compared against a standard 2-phase design.Item Non-Isotropic Material Distribution Topology Optimization for Fused Deposition Modeling Products(University of Texas at Austin, 2015) Hoglund, Robert; Smith, Douglas E.Mechanical properties of products produced with the Fused Deposition Modeling (FDM) process are known to be dependent on bead direction, especially when short fiber reinforcement is added to the polymer filament feedstock. As a result, the structural performance of fiber-filled FDM parts is expected to be improved by simultaneously computing preferred deposition directions while optimizing the internal support structure. This paper presents a topology optimization method for computing the material distribution within a fiber-reinforced polymer composite FDM part that incorporates the non-isotropic mechanical properties of the bead structure. Unlike the well-established homogenization topology optimization method which determines pointwise orthotropic properties by increasing the complexity of the design problem, our approach takes advantage of the simplicity of the SIMP method where the underlying orthotropic orientation is assumed. Computed results show the effect that the orientation of fiber filled bead orthotropic microstructure has on part topology for 2D FDM parts.Item An Optimization Based Design Framework for Multi-Functional 3D Printing(University of Texas at Austin, 2013-08-16) Brackett, D.; Panesar, A.; Ashcroft, I.; Wildman, R.; Hague, R.This work investigates design analysis and optimization methods for the integration of active internal systems into a component for manufacture using multi-material 3D printing processes. This enables efficient design of optimal multifunctional components that exploit the design freedoms of additive manufacturing (AM). The main contributions of this paper are in two areas: 1) the automated placement and routing of electrical systems within the component volume and, 2) the accommodation of the effect of this system integration on the structural response of the part through structural topology optimization (TO). A novel voxel modeling approach was used to facilitate design flexibility and to allow direct mapping to the 3D printer jetting nozzles.Item Product Optimization with and for Additive Manufacturing(University of Texas at Austin, 2016) Reiher, T.; Koch, R.Additive Manufacturing offers a great potential for the optimization of products. Therefore different approaches are feasible to exploit these potentials for elaborating optimal solutions. For example these include optimization of weight or stiffness of structural components as well as the integration of functions and other entities of assemblies. Note, however, that additive manufacturing processes have process specific limitations. Products, components and assemblies, as well as procedures for the design and production preparation must be optimized with regard to a successful additive manufacturing. The use of already known tools for the optimization and design needs to be reconsidered and adapted to the additive manufacturing. This also includes the production planning with component orientation in build chamber as well as a necessary quality management system. This paper shows several ways for product optimization with additive manufacturing, often based on topology optimization, and procedures for information gathering, decision making and shape determination for part optimization for Additive Manufacturing.