Browsing by Subject "support structures"
Now showing 1 - 16 of 16
- Results Per Page
- Sort Options
Item Additive Manufacturing with Modular Support Structures(University of Texas at Austin, 2018) Yigit, Ismail Enes; Isa, Mohammed; Lazoglu, IsmailAdditive manufacturing is praised to have low material waste compared to conventional subtractive manufacturing methods. This is not always the case when the computer aided design (CAD) model consists of large overhangs. In such cases, fabrication of support structures are required to fill the space between the CAD model and the manufacturing bed. In post processing, these support structures must be removed from the model. These supports become waste and reduce the buy-to-fly ratio. In this paper, we present a pre-fabricated reusable modular support structure system which minimizes the fabrication of conventional support structures. The conventional supports are replaced with modular support blocks wherever possible. The blocks are stacked under the overhang with a robot arm until the overhang of the model is reached. Conventional supports can be fabricated on top when needed with fused filament fabrication. This strategy reduces fabrication of conventional supports. Thus, faster fabrication times are obtained with higher buy-to-fly ratios.Item Assessing New Support Minimizing Strategies for the Additive Manufacturing Technology SLM(University of Texas at Austin, 2013-08-16) Cloots, M.; Spierings, A.B.; Wegener, K.To successfully produce metal parts by SLM, additional support structures are needed to support overhanging surfaces in order to dissipate process heat and to minimize geometrical distortions induced by internal stresses. These structures are often massive and require additional post-processing time for their removal. A minimization of the extent to which support structures are needed would therefore significantly reduce manufacturing and finishing efforts and costs. A specific component segmentation strategy is developed. It allows the segmentation of critical areas of the component by applying a specific scanning strategy with appropriate energy input and optimized supporting strategies. The results indicate that the supporting effort can generally be reduced, e.g. overhang geometries with an angle to the horizontal of less than 35° can be manufactured without any support. The successful realization of the segmentation strategy in combination with optimized support structures allows the implementation of a stacking strategy, thereby using the available work space more efficiently.Item DEPICTION OF SUPPORT STRUCTURES IN TECHNICAL DRAWINGS(University of Texas at Austin, 2023) Lammers, S.; Koers, T.; Magyar, B.; Zimmer, D.; Lieneke, T.To ensure uniform documentation of support structure information, a concept is presented that enables a standardized depiction of support structures in technical drawings based on ISO 128-3. To this end, requirements for a uniform depiction are defined and a procedure for drawing entry is presented. The drawing entry should contain all production-relevant support structure information. The standardized documentation of support structure information in technical drawings is intended to ensure a simple, clear and safe exchange of information between business units or different companies along the value chain. As a result a possible drawing entry of support structures was developed. To distinguish between different support structure types, a standardized depiction of geometrical information in a specification field is shown. The specification field gives a detailed description of the support structure type, the geometry as well as the connection to the part and the building platform. Also uncommon support types like lattice structures or CAD based support structures can be implemented. To ensure the usability the depiction is editable and extendable.Item Development of a Method to Derive Design Guidelines for Production-suitable Support Structures in Metal Laser Powder Bed Fusion(University of Texas at Austin, 2021) Lammers, S.; Lieneke, T.; Zimmer, D.Solid support structures in metal laser powder bed fusion have a significant influence on the economic applicability, component quality and process stability and represent a central challenge for widespread industrial use. As the connection of the components to the building platform by supports is essential, the negative effects must be minimized at the same time as the supporting effect is optimized. Within the scope of this study, a standardized method is developed that allows the investigation of several support structures and parameters with regard to their influence on the target variables: component quality, process efficiency and stability. In addition to the proof of general suitability, the applicability is investigated using so-called standard elements. Based on the experimental results, design guidelines are derived, which will serve as a basis for decision-making during the selection of support structure for an individual application.Item Dynamic Build Bed for Additive Manufacturing(University of Texas at Austin, 2019) Yigit, Ismail Enes; Lazoglu, IsmailCompared to subtractive manufacturing, additive manufacturing generally has low material waste. However, models with large overhangs require manufacturing of support structures which ends up as waste material. This paper proposes the use of a dynamic build bed for reducing support structures. The bed consists of an array of actuated pins which move in the build orientation. Each pin can be individually moved to the correct height for supporting the given model. Two separate applications of the build bed are investigated. In the first application, the dynamic build bed is used as support structures in deposition-based AM methods. The pins individually raise out of the build bed to support the overhang geometry at the given deposition height. The second application is in powder-based AM methods. In the second application, the pins are used to fill the space of the powder where the geometry will not occupy. The pins are individually lowered in the build orientation to make space for a new powder layer. Thus, saving excessive deposition of powder.Item Enabling Cost-based Support Structure Optimization in Laser Powder Bed Fusion of Metals(University of Texas at Austin, 2021) Bartsch, K.; Emmelmann, C.Support structures are essential to laser powder bed fusion (PBF-LB/M). They sustain overhangs, prevent distortion, and dissipate process-induced heat. Their removal after manufacturing is required, though, increasing the overall costs. Therefore, optimization is important to increase the economic efficiency of PBF-LB/M. To enable optimization focused on the support structures’ costs, a cost model is developed. The whole production process, including the design, manufacturing, and post-processing of a part is considered by deriving formulas for the individual costs. The cost model is applied to a benchmark procedure previously developed. Additionally, a case study investigating different support layout strategies is conducted.Item Investigation of Support Structures for Direct Metal Laser Sintering (DMLS) of IN625 Parts(University of Texas at Austin, 2015) Poyraz, Ö.; Yasa, E.; Akbulut, G.; Orhangül, A.; Pilatin, S.Along with the increased application of additive manufacturing (AM) in the aerospace industry, a better understanding of different aspects for the technique has become necessary to fulfill the high demands of reliability and robustness. The ability to introduce very complex, even internal, features into part design with AM appeals everyday many design engineers to this new group of technologies. In this respect, new design rules for AM are being researched, developed and updated day-to-day. Although, it is commonly stated that AM offers limitless geometrical complexity, there are some limits of the technology. For Direct Metal Laser Sintering (DMLS), a metal powder fusion AM process, one of the major limitations in the geometrical freedom offered by AM is the overhang surfaces which necessitates melting on loose powder and lead to dross formation, distortions, curling, etc. Support structures to be built together with the target part thus become necessary and critical to avoid such undesired results and moreover to facilitate a uniform heat dissipation. Design of the support structures which are easy to apply and remove is therefore among the important research topics in AM. The compromise in the design of support structures roots from the fact that the support structures must be strong enough to connect the part to provide resistance for curling up and they are desired to be loose enough to be easily removed. In addition, redundant use of support structures increases the amount of material spent, production time as well as postprocessing efforts. This paper presents an investigation of different support structure designs; applied onto a thin-walled IN625 part, manufactured using DMLS.Item LIQUID METAL JETTING OF ALUMINUM PARTS WITH SALT SUPPORT STRUCTURES(University of Texas at Austin, 2023) Kirchebner, Benedikt; Weidner, Christoph; Ploetz, Maximilian; Rehekampff, Christoph; Volk, Wolfram; Lechner, PhilippLiquid metal jetting (LMJ) bears the potential of being a fast part manufacturing technology while using a cheap raw material. LMJ is a subtype of material jetting (MJT) and the parts are built by successively depositing droplets of molten metal onto a build platform. For full 3D capability, support structures are necessary, which must be removed in subsequent processes. In previous investigations, we proposed the usage of water-soluble salt as a support material, selected a suitable salt, and analyzed the influence of this material on aluminum parts made in LMJ. The present work shows a duplex MJT print head for processing aluminum alloys and KClNaCl salt. Various printing sequences and support structure strategies are compared. The results show that the sequence of printing aluminum and salt is crucial. Furthermore, using thin layers of the support material as a release layer appears promising.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 New Support Structures for Reduced Overheating on Downfacing Regions of Direct Metal Printed Parts(University of Texas at Austin, 2019) Paggi, Umberto; Ranjan, Rajit; Thijs, Lore; Ayas, Can; Langelaar, Matthijs; van Keulen, Fred; van Hooreweder, BrechtIn Laser Powder Bed Fusion (LPBF), the downfacing surfaces usually have increased surface roughness and reduced dimensional accuracy due to local overheating and warpage. To partially overcome this a new supporting structure is developed in this study, namely the contactless support. This is a thin blade parallel to the critical area which transfer the heat away from the melt pool via conduction through the powder bed instead of direct contact. The support is tested in different geometries and printing conditions to define the optimal distance from the part and its effectiveness is evaluated by measuring the surface roughness of the samples. Numerical modelling of heat transfer phenomenon is also employed to determine the thermal history of the printing process and understand which parameters define the optimal distance for the thermal supports. Finally topology optimization is used to create a support structure which minimize the wasted material while keeping the heat flow optimal.Item Optimization of Supports in Metal-Based Additive Manufacturing by Means of Finite Element Models(University of Texas at Austin, 2012-08-15) Krol, T.A.; Zach, F.; Seidel, C.Metal-based additive manufacturing processes require a supporting of overhanging part areas during the powder solidification e. g. for improving the heat dissipation to the substrate. Technology users nowadays strive to reduce support areas due to economical aspects, while simultaneously enhancing the process stability by maximizing the support stiffness. For the simplification and acceleration of this support design procedure, the presented work describes a methodology for optimizing support structures by means of finite element models. Thereby, the main approaches are covering a fractal adaptation of the support layout and an optimization of block supports depending on the calculation results. The presented methods were applied by using experimental components.Item Support-Free Sintering of 3D Printed Binder Jet Copper and Stainless Steel Parts(2022) Jangam, John Samuel Dilip; Anthony, Thomas; McKinnell, Jim; Pon, Ben; Piderman, Jake; Zhao, LihuaBinder jet additive manufacturing involves selectively applying a binder, layer-by-layer, to produce green parts, followed by a high temperature sintering treatment. During sintering, green parts are inherently prone to undesired part distortion/sag in the unsupported regions. Traditional methods use 3D printed supports or machined ceramic setters to avoid the part distortion/sag during sintering. We introduce a shape-retaining-stimulus coating that will mitigate/eliminate the need of additional supports during sintering. Simply supported coper and stainless steel green parts of various thickness were evaluated for part distortion. Our experimental results demonstrate that a selective application of the shape-retaining-stimulus coating on 3D printed copper parts with a spanning up to 50 mm, and stainless steel parts spanning up to 33 mm can be sintered without auxiliary supports. Our shape-retaining-stimulus coating produces exceptional results, and the ease of removal makes it an attractive candidate.Item Support-free sintering of 3D printed binder jet copper and stainless steel parts(2022) Jangam, John Samuel Dilip; Anthony, Thomas; McKinnell, Jim; Pon, Ben; Piderman, Jake; Zhao, LihuaBinder jet additive manufacturing involves selectively applying a binder, layer-by-layer, to produce green parts, followed by a high temperature sintering treatment. During sintering, green parts are inherently prone to undesired part distortion/sag in the unsupported regions. Traditional methods use 3D printed supports or machined ceramic setters to avoid the part distortion/sag during sintering. We introduce a shape-retaining-stimulus coating that will mitigate/eliminate the need of additional supports during sintering. Simply supported coper and stainless steel green parts of various thickness were evaluated for part distortion. Our experimental results demonstrate that a selective application of the shape-retaining-stimulus coating on 3D printed copper parts with a spanning up to 50 mm, and stainless steel parts spanning up to 33 mm can be sintered without auxiliary supports. Our shape-retaining-stimulus coating produces exceptional results, and the ease of removal makes it an attractive candidate.Item Towards directed energy deposition of metals using polymer-based supports: porosity of 316L stainless steel deposited on carbon-fiber-reinforced ABS(2022) Kurfess, Rebecca; Saleeby, Kyle; Feldhausen, Thomas; Fillingim, Blane; Hart, A. John; Hardt, DavidDirected energy deposition (DED) is increasingly valuable to many industries because of its high deposition rates relative to other metal additive manufacturing processes, but the design space of DED is limited. For instance, steep overhangs are difficult or impossible to manufacture. Polymer-based support structures could help address this challenge. The viability of DED on polymer composite substrates has begun to be explored, specifically with 316L stainless steel on carbon-fiber-reinforced ABS substrates. Monolithic metal components can be deposited on the polymer, but it was found that gas release during polymer degradation causes porosity due to gas entrapment in the metal. An interlayer cooling time was introduced to reduce polymer degradation and decrease the porosity due to gas entrapment, but this led to porosity from lack of fusion. The results of this work provide insight into process parameter selection and scan strategy development to enable the use of polymer support structures in blown-powder DED.Item Truss-Type Support Structures for SLM(University of Texas at Austin, 2021) Subedi, Subodh C.; Thoma, Dan J.; Suresh, KrishnanSupport structures are critical in selective laser melting (SLM) of 3D metal additively manufactured components. Besides providing structural support, they serve as conduits for efficient heat dissipation. Support structures heavily influence the printability of a part as well as its physical and mechanical properties. Commonly used thin walled surface support structures are reliable, but are difficult to optimize, post-process, and often entrap a significant amount of powder. This paper presents the concept of truss-type surface support structures for SLM to address these challenges. The proposed structures are easy to optimize and provide better anchorage; further, they do not entrap powder, and are easy to remove. Experimental results demonstrate the effectiveness of these designs over commonly used support structures, paving a path towards optimal support structure design for SLM.Item Using Parallel Computing Techniques to Algorithmically Generate Voronoi Support and Infill Structures for 3D Printed Objects(University of Texas at Austin, 2019) Williams, T.; Langehennig, S.; Ganter, M.; Storti, D.Many methods of 3D printing rely on support and infill structures in order to produce quality parts. This paper formulates an algorithm that produces support and/or infill structures based on Voronoi cells for objects described by a function or a closed triangulated mesh. The algorithm utilizes Voronoi structures with a high degree of customization provided to the end user, and takes advantage of parallel computing to cut down on the computation time required to generate these structures. The aforementioned method is novel because it uses Voronoi structures as supports and combines support and infill generation into a single process, displaying the flexibility of Voronoi foam structures in 3D printing applications. The primary focus is the implementation of the algorithm itself and the customization capabilities it provides.