Nonterrestrial utilization of materials: Automated space manufacturing facility

Four areas related to the nonterrestrial use of materials are included: (1) material resources needed for feedstock in an orbital manufacturing facility, (2) required initial components of a nonterrestrial manufacturing facility, (3) growth and productive capability of such a facility, and (4) automation and robotics requirements of the facility

Development of Novel Low-Cost Rapid Tooling Solution by Incorporating Fused Deposition Modeling Sacrificial Patterns

Injection molding and additive manufacturing (3D-printing) are two manufacturing solutions that are suitable to produce plastic components. The material extrusion-based additive manufacturing (AM) process deposits beads side by side through an extrusion to build prototypes. This process is capable of manufacturing complex geometries, but it is very expensive and slow. As a result, it is not the best solution for manufacturing low to medium (10-5000) production volumes. Additionally, there are limited materials for AM as compared to injection molding. Injection molding process is very fast, reliable, and low-cost to produce thousands of a single product in a short time. However, the initial investment for building the mold is very high and it may take up to several weeks to manufacture a good quality mold. To cover the gap between these two processes, a low-cost tooling solution with a reduced build time has been developed that is suitable for low to medium production. Internal features are integrated within the tooling to investigate the possibility of building internal channels that can later be optimized to improve the cooling efficiency of the tool. The developed tooling solution was designed for a hands-free door handle. Design for manufacturing (DfM) strategies were applied to the initial CAD design to make it suitable for an injection molding process. Finite element analysis (FEA) and injection molding simulations were used to conduct virtual studies on this low-cost tooling solution. To create the internal features, soluble material (SR-30 developed by Stratasys) was used and Aremco 805 epoxy was cast to create the mold cavities. After curing the epoxy, the soluble patterns were dissolved to create the final mold. The developed tooling was able to manufacture the J-hook with a dimensional precision of approximately 1% - 3% of the desired geometries. Additionally, no sink mark or shrinkage was observed on the surfaces of the final product. Most importantly, the cost of the solution was kept under 500 CAD dollars and complex internal features were built without any additional support structure on the inside. Build time of the J-hook was reduced from 3 hours to less than 2 minutes and most importantly, the piece price of each J-hook was lowered by more than 44 CAD dollars per piece

Intelligent system to support micro injection process through artificial intelligent techniques and cae model integration

Trabajo de investigaciónIn this project a propose of integration of CAE Modeling and artificial intelligence systems to support the process in the production of micro plastic parts is presented. Based on analysis provided by CAE systems, studies will be carried out for diverse parts, to be analyses and throw to artificial intelligent techniques give recommendations of optimal values of plastic micro injection process.1. INTRODUCTION 2. PROBLEM STATEMENT 3. OBJECTIVES 4. CONCEPTUAL FRAMEWORK 5. THEORETICAL FRAMEWORK 6. STATE OF THE ART 7. METHODOLOGY 8. DESCRIPCION OF PROJECT 9. RESULTS 10. VALIDATION OF PROJECT 11. CONCLUSIONS AND FUTURE WORKS 12. REFERENCES 13. ANNEXESMaestríaMagister en Ingeniería y Gestión de la Innovació

Size and shape specific particles toward biomedical imaging: design, fabrication, and characterization

Thesis (Ph.D.)--Boston UniversityThe power of a biomedical imaging modality can be augmented and is, in large part, determined by the capabilities of the available contrast agents. For example, quantum dots represent a colorful palette of powerful contrast agents for optical fluorescence imaging and Raman spectroscopy, given their tunable multiplexing capability and long-term stability compared to traditional organic molecule-based fluorescent labels. On the contrary, as the workhorses in both clinical and research imaging, the full potentials of magnetic resonance imaging and computed tomography have yet to be actualized due to several existing fundamental limitations in the currently available contrast agents, including but not limited to, the lack of multiplexing capability, low sensitivity, as well as the lack of functional imaging capacity. Leveraging both traditional top-down micro- and nanoelectromechanical systems fabrication techniques and bottom-up self-assembly approaches, this dissertation explores the possibility of mitigating these limitations by engineering precisely controllable, size and shape (as well as a host of other materials properties) specific micro- and nanoparticles, for use as the next generation contrast agents for magnetic resonance imaging and computed tomography. Herein, the ways by which engineering approaches can impact the design, fabrication and characterization of contrast agents is investigated. Specifically, different configmations of magnetic micro- and nanoparticles, including double-disk and hollow-cylinder structmes, fabricated using a top-down approach were employed as magnetic resonance imaging contrast agents enabled with a multiplexing capability and improved sensitivity. Subsequently, a scalable nanomanufactming platform, utilizing nanoporous anodized aluminum oxide membranes as templates for pattern transfer as well as thermal/ultraviolet nanoimprinting techniques, was developed for the high throughput fabrication of size and shape specific polymeric nanorods. When ladened with X-ray attenuating tantalum oxide nanoparticle payloads, these polymeric nanorods can be used as contrast agents for computed tomography, yielding prolonged vascular circulation times, improved sensitivity, as well as targeted imaging capabilities. Furthermore, by applying various payload materials, this nanomanufacturing platform also has the flexibility to produce contrast agents for other imaging modalities, as well as the potential to realize dual-purpose agents for both diagnostic and therapeutic applications

Formula SAE Monocoque Chassis Development

Formula SAE is a collegiate competition hosted by SAE International with the primary goal being to design, manufacture, and race an open wheel race car. The Cal Poly Racing Formula SAE team strives for improvement every race season and has remained competitive as a result. The 2019-2020 management team determined that further research and development towards the chassis would yield the greatest performance benefit for future seasons, as the previous chassis platform limited packaging and mounting options for vehicle subsystems which interfaced with the chassis. A redesign of the Cal Poly Racing Formula SAE team’s carbon fiber reinforced polymer monocoque chassis was requested to improve subsystem integration, increase torsional stiffness, and reduce weight compared to the previous platform. Specifically, this senior project team focused on manufacturing process improvement and laminate design to meet these goals for the 2020 Formula SAE competition. This report details the design and manufacturing of such a chassis. Specific emphasis was placed on the geometry, laminate, and manufacturing process design. The geometry was designed using subsystem input for satisfactory integration of all subsystem components while maintaining a high specific torsional stiffness. The team also developed numerous analysis tools including spreadsheets and finite element models to design the asymmetric laminate of the chassis. Modular, multi-piece tooling was designed to produce a single-piece chassis and to allow for easy geometric changes in the future. Though two complete chassis were delivered to the Formula SAE team, the outbreak of COVID-19 prevented the collection of data that would have been used to validate the design. However, the Formula SAE team was made aware of the validation plan proposed in this report

Advanced Gas Turbine (AGT) powertrain system development for automotive applications

Rotor dynamic instability investigations were conducted. Forward ball bearing hydraulic mount configurations were tested with little effect. Trial assembly of S/N 002 ceramic engine was initiated. Impeller design activities were completed on the straight line element (SLE) blade definition to address near-net-shape powder metal die forging. Performance characteristics of the Baseline Test 2A impeller were closely preserved. The modified blading design has been released for tooling procurement. Developmental testing of the diffusion flame combustor (DFC) for initial use in the S/N 002 2100 F ceramic structures engine was completed. A natural gas slave preheater was designed and fabricated. Preliminary regenerator static seal rig testing showed a significant reduction in leakage and sensitivity to stack height. Ceramic screening tests were completed and two complete sets of ceramic static structures were qualified for engine testing. Efforts on rotor dynamics development to resolve subsynchronous motion were continued

An Investigation of the Native and Manipulated Effects of Shear Imbalanced Melt Flows during Molding Processes

Runner-based shear imbalances is a common feature in injection molding of polymers. Its effect on the melt flow is a main concern, causing problems even in cases where the mold cavities are naturally balanced and the geometry is traditionally defined. Melt rotation technology has been applied to address this issue, as well as that of shrinkage and warpage.In the present study, this technology is taken several steps further with the goal of exploring and solving product quality variations that is attributed to the imbalanced polymer melt flow problem. Molding trials were conducted with and without melt rotation using several types of polymers, and the resultant effects on the physical, thermal, and mechanical properties of the molded products were explored. The study found that important product quality parameters such as crystallinity and tensile modulus vary significantly throughout conventionally molded products, and that these can be dramatically altered by implementation of the melt rotation technology. For semi-crystalline materials, specimens taken from product regions associated with higher melt flow shear levels exhibited higher crystallinity levels as well as higher tensile moduli due to the localized shear rate variation.This work also includes visual analysis of how shearing of the polymer through the runner system affects mold filling in real-time. Multi-cavity molding is widely used to increase manufacturing efficiency by primarily reducing time and cost. It is mainly generally accepted that the optimal runner design is one that is geometrically balanced. However, is now also understood that imbalances are also due to the shearing of the polymer melt as it is pushed through the runner system. To gain a deeper understanding on how this occurs, a custom-built mold with transparent mold inserts and runner system was utilized. Cavity filling of polymers into different cavity designs was captured using a high-speed camera. Analysis of this visual data would provide aid in finding methods to mitigate the non-uniform behavior of molten polymers undergoing shear-thinning. Molding trials were implemented and experimental results have been found to support the effectiveness of the melt rotation technology.The results in this work also show the potential of adopting the technology for a broader range of applications that require a homogeneous polymer melt flow for ensuring efficient manufacturing and desired quality products

A multiple objective optimization approach to quality control

The use of product quality as the performance criteria for manufacturing system control is explored. The goal in manufacturing, for economic reasons, is to optimize product quality. The problem is that since quality is a rather nebulous product characteristic, there is seldom an analytic function that can be used as a measure. Therefore standard control approaches, such as optimal control, cannot readily be applied. A second problem with optimizing product quality is that it is typically measured along many dimensions: there are many apsects of quality which must be optimized simultaneously. Very often these different aspects are incommensurate and competing. The concept of optimality must now include accepting tradeoffs among the different quality characteristics. These problems are addressed using multiple objective optimization. It is shown that the quality control problem can be defined as a multiple objective optimization problem. A controller structure is defined using this as the basis. Then, an algorithm is presented which can be used by an operator to interactively find the best operating point. Essentially, the algorithm uses process data to provide the operator with two pieces of information: (1) if it is possible to simultaneously improve all quality criteria, then determine what changes to the process input or controller parameters should be made to do this; and (2) if it is not possible to improve all criteria, and the current operating point is not a desirable one, select a criteria in which a tradeoff should be made, and make input changes to improve all other criteria. The process is not operating at an optimal point in any sense if no tradeoff has to be made to move to a new operating point. This algorithm ensures that operating points are optimal in some sense and provides the operator with information about tradeoffs when seeking the best operating point. The multiobjective algorithm was implemented in two different injection molding scenarios: tuning of process controllers to meet specified performance objectives and tuning of process inputs to meet specified quality objectives. Five case studies are presented

Polymer-Ceramic Composites for 3D Inkjet Printing

Als eine der wenigen additiven Fertigungsmethoden ermöglicht der 3D-Tintenstrahldruck die Multimaterialabscheidung. Es besteht jedoch ein Bedarf an Funktions- und Strukturmaterialien. Unter anderem werden thermisch leitfähige Polymer-Keramik-Komposite zur thermischen Regulierung benötigt. In dieser Arbeit wurden drei neue Arten von Al2O3-Partikel gefüllten Tinten hergestellt und untersucht. Allen voran sind es die thermisch leitfähigen, Partikel gefüllten Tinten, die anfänglich ohne, später aber mit volatilen Lösungsmitteln hergestellt wurden, um den Füllgrad zu steigern. Des Weiteren wurden Untersuchungen zu der Auswirkung von Nanopartikeln auf die Zähigkeit und Bruchdehnung von Kompositen angestellt, welche in lösungsmittelfreien UV härtbaren Tinten mündeten. Bei der Herstellung wurde die Keramik in einer Planetenkugelmühle homogenisiert und zerkleinert. Zeitgleich oder im Anschluss an die Mahlung wurden den Partikeln die Dispergatoren 3-(Trimethoxysilyl)propylmethacrylat oder 2-[2-(2-Methoxyethoxy)ethoxy]essig-säure hinzugegeben. Je nachdem, ob die Mahlung in einem volatilen Mahlmedium oder direkt schon in der organischen Matrix stattfand, wurden die Partikel im ersteren Fall getrocknet und im letzteren direkt für die Verwendung abgefüllt. Die getrockneten Partikel wurden im Anschluss in die organische Matrix eingearbeitet. Der Prozess wurde von Analysemessungen begleitet, welche zum einen das Pulver und zum anderen die fertige Komposit-Tinte charakterisierten. Die Charakterisierung der Tinten umfasste rheologische Messungen, Stabilitätsuntersuchungen und Tintenstrahl-Drucktests. Gedruckte Komposit-Prüfkörper wurden mechanisch und thermisch analysiert. Die Nanokomposit-Tinten zeigten keine nennenswerten Verbesserungen der mechanischen Eigenschaften bei den untersuchten Parametern. Die zweite lösungsmittelfreie Tinte führt zu einem Komposit mit einem Füllgrad von 30 Vol% und einer thermischen Leitfähigkeit von 0,6 W/(m·K). Die Untersuchung der lösungsmittel-haltigen Tinten ergab ein Material mit einem Füllgrad von 50 Vol% und einer thermischen Leitfähigkeit von 1 W/(m·K), ein bisher unerreichtes Ergebnis. Die mechanischen Eigenschaften zeigten einen E-Modul von 2,4 GPa, eine Zugfestigkeit von 40 MPa, eine Bruchdehnung von 1 % und eine Zähigkeit von 1,3 J/m³. Sowohl die lösungsmittelfreie als auch lösungsmittelhaltige Tinte wurden für die Herstellung von Komponenten zu Demonstrationszwecken verwendet

Characterization of thermal and mechanical properties of polypropylene-based composites for fuel cell bipolar plates and development of educational tools in hydrogen and fuel cell technologies

In this project we developed conductive thermoplastic resins by adding varying amounts of three different carbon fillers: carbon black (CB), synthetic graphite (SG) and multi-walled carbon nanotubes (CNT) to a polypropylene matrix for application as fuel cell bipolar plates. This component of fuel cells provides mechanical support to the stack, circulates the gases that participate in the electrochemical reaction within the fuel cell and allows for removal of the excess heat from the system. The materials fabricated in this work were tested to determine their mechanical and thermal properties. These materials were produced by adding varying amounts of single carbon fillers to a polypropylene matrix (2.5 to 15 wt.% Ketjenblack EC-600 JD carbon black, 10 to 80 wt.% Asbury Carbon\u27s Thermocarb TC-300 synthetic graphite, and 2.5 to 15 wt.% of Hyperion Catalysis International\u27s FIBRILTM multi-walled carbon nanotubes) In addition, composite materials containing combinations of these three fillers were produced. The thermal conductivity results showed an increase in both through-plane and in-plane thermal conductivities, with the largest increase observed for synthetic graphite. The Department of Energy (DOE) had previously set a thermal conductivity goal of 20 W/m·K, which was surpassed by formulations containing 75 wt.% and 80 wt.% SG, yielding in-plane thermal conductivity values of 24.4 W/m·K and 33.6 W/m·K, respectively. In addition, composites containing 2.5 wt.% CB, 65 wt.% SG, and 6 wt.% CNT in PP had an in–plane thermal conductivity of 37 W/m·K. Flexural and tensile tests were conducted. All composite formulations exceeded the flexural strength target of 25 MPa set by DOE. The tensile and flexural modulus of the composites increased with higher concentration of carbon fillers. Carbon black and synthetic graphite caused a decrease in the tensile and flexural strengths of the composites. However, carbon nanotubes increased the composite tensile and flexural strengths. Mathematical models were applied to estimate through-plane and in-plane thermal conductivities of single and multiple filler formulations, and tensile modulus of single-filler formulations. For thermal conductivity, Nielsen\u27s model yielded accurate thermal conductivity values when compared to experimental results obtained through the Flash method. For prediction of tensile modulus Nielsen\u27s model yielded the smallest error between the predicted and experimental values. The second part of this project consisted of the development of a curriculum in Fuel Cell and Hydrogen Technologies to address different educational barriers identified by the Department of Energy. By the creation of new courses and enterprise programs in the areas of fuel cells and the use of hydrogen as an energy carrier, we introduced engineering students to the new technologies, policies and challenges present with this alternative energy. Feedback provided by students participating in these courses and enterprise programs indicate positive acceptance of the different educational tools. Results obtained from a survey applied to students after participating in these courses showed an increase in the knowledge and awareness of energy fundamentals, which indicates the modules developed in this project are effective in introducing students to alternative energy sources