1,720,967 research outputs found
Modelling flexibility and qualification ability to assess electric propulsion architectures for satellite megaconstellations
No full textThe higher satellite production rates expected in new megaconstellation scenarios involve radical changes in the way design trade-offs need to be considered by electric propulsion companies. In relative comparison, flexibility and qualification ability will have a higher impact in megaconstellations compared to traditional businesses. For these reasons, this paper proposes a methodology for assessing flexible propulsion architectures by taking into account variations in market behavior and qualification activities. Through the methodology, flexibility and qualification ability can be traded against traditional engineering attributes (such as functional performances) in a quantitative way. The use of the methodology is illustrated through an industrial case related to the study of xenon vs. krypton architectures for megaconstellation businesses. This paper provides insights on how to apply the methodology in other case studies, in order to enable engineering teams to present and communicate the impact of alternative architectural concepts to program managers and decision-makers
Fuzzy model-based design for testing and qualification of additive manufacturing components
Full text linkThe uncertainties and variation of additive manufacturing (AM) material properties and their impact on product quality trouble designers. The lack of experience in AM technologies renders the experts' assessment of AM components and the establishment of safety margins difficult. Consequently, unexpected qualification difficulties resulting in expensive and lengthy redesign processes might arise. To reduce the risk of qualification failure, engineers might perform copious time-consuming and expensive specimen testing in early phases, or establish overconservative design margins, overriding the weight reduction benefits of AM technologies. In this article, a model-based design method is proposed for the conceptual design of AM space components with affordable test phases. The method utilizes fuzzy logics to systematically account for experts' assessment of AM properties variation, and to provide an early estimation of a product qualification likelihood related to design parameters of interest, without the need for copious testing. The estimation of qualification likelihood can also point out which are the unique AM material uncertainties that require further specific testing, to enable the design of a product with a better performance and more affordable test phases. The method is demonstrated with the design for AM gridded of ion thrusters for satellite applications
Impact on design when introducing additive manufacturing in space applications
No full textThis paper studied how the introduction of additive manufacturing (AM) in space applications impacts the design phases. Together with three manufacturers of space applications, the potential benefit as well as constraints are studied to identify design gaps. A literature survey is conducted to match the needs and following an analysis the impact on design practice is formulated. Results show the need to combine a wider design exploration capability, in combination with comparative modelling strategies
Modular product design for additive manufacturing of satellite components: maximising product value using genetic algorithms
No full textFor space manufacturers, additive manufacturing promises to dramatically reduce weight and costs by means of integral designs achieved through part consolidation. However, integrated designs hinder the ability to change and service components over time – actually increasing costs – which is instead enabled by highly modular designs. Finding the optimal trade-off between integral and modular designs in additive manufacturing is of critical importance. In this article, a product modularisation methodology is proposed for supporting such trade-offs. The methodology is based on combining function modelling with optimisation algorithms. It evaluates product design concepts with respect to product adaptability, component interface costs, manufacturing costs and cost of post-processing activities. The developed product modularisation methodology is derived from data collected through a series of workshops with industrial practitioners from three different manufacturer companies of space products. The implementation of the methodology is demonstrated in a case study featuring the redesign of a satellite antenna
Analysing increase of functionality and complexity in integrated product architectures
No full textNowadays, product designers find difficulties and uncertainties when assessing how complex a product will be when introducing new functionalities and technologies or when integrating multiple functionalities into a single component. There is a limited number of studies correlating functionality increase to product complexity. In this paper, the impact of functionality on complexity is quantitatively analyzed in two different case studies: one regarding a set of valves to study how complexity is affected when adding new functionalities, and another one related to three alternative designs of computer mice that features different degrees of functional integration. In the first case study, it has been found that adding new functionalities leads to a super-linear increase of complexity. In the second case study, it has been found that integrating functionality through the introduction of new electronic elements allows to reduce the total number of components, suggesting a decrease in complexity. However, the case study shows an increase in the product's overall complexity through an increased number of interactions between the components themselves. This means that possessing a quantitative methodology to evaluate the impact of functionality increase in product complexity can be an important means for designers to avoid misconceptions and risks during the early phases of product development
Drivers and guidelines in design for qualification using additive manufacturing in space applications
No full textIn recent years, reducing cost and lead time in product development and qualification has become decisive to stay competitive in the space industry. Introducing Additive Manufacturing (AM) could potentially be beneficial from this perspective, but high demands on product reliability and lack of knowledge about AM processes make implementation challenging. Traditional approaches to qualification are too expensive if AM is to be used for critical applications in the near future. One alternative approach is to consider qualification as a design factor in the early phases of product development, potentially reducing cost and lead time for development and qualification as products are designed to be qualified. The presented study has identified factors that drive qualification activities in the space industry and these “qualification drivers” serve as a baseline for a set of proposed strategies for developing “Design for Qualification” guidelines for AM components. The explicit aim of these guidelines is to develop products that can be qualified, as well as appropriate qualification logics. The presented results provide a knowledge-base for the future development of such guidelines
Constraint replacement-based design for additive manufacturing of satellite components: Ensuring design manufacturability through tailored test artefacts
No full textAdditive manufacturing (AM) is becoming increasingly attractive for aerospace companies due to the fact of its increased ability to allow design freedom and reduce weight. Despite these benefits, AM comes with manufacturing constraints that limit design freedom and reduce the possibility of achieving advanced geometries that can be produced in a cost-efficient manner. To exploit the design freedom offered by AM while ensuring product manufacturability, a model-based design for an additive manufacturing (DfAM) method is presented. The method is based on the premise that lessons learned from testing and prototyping activities can be systematically captured and organized to support early design activities. To enable this outcome, the DfAM method extends a representation often used in early design, a function-means model, with the introduction of a new model construct-manufacturing constraints (Cm). The method was applied to the redesign, manufacturing, and testing of a flow connector for satellite applications. The results of this application-as well as the reflections of industrial practitioners-point to the benefits of the DfAM method in establishing a systematic, cost-efficient way of challenging the general AM design guidelines found in the literature and a means to redefine and update manufacturing constraints for specific design problems
SUPPORTING ADDITIVE MANUFACTURING TECHNOLOGY DEVELOPMENT through CONSTRAINT MODELLING in EARLY CONCEPTUAL DESIGN: A SATELLITE PROPULSION CASE STUDY
No full textFunction and constraints modelling are implemented to design two gridded ion thrusters for additive manufacturing (AM). One concept takes advantage of AM design freedom, disregarding AM limitations and is not feasible. The other concept considers AM limitations and is manufacturable and feasible. Constraints modelling highlights AM capabilities that can be improved, showing where future investment is needed. Constraints representation can also support the creation of technology development roadmaps able to identify areas of AM technologies that must be improved
Function modelling and constraints replacement to support design for additive manufacturing of satellite components
No full textAdditive Manufacturing is increasingly attracting interest among manufacturers of space components, mainly due to its high design freedom, capability for achieving weight reduction and for being cost-efficiently produced in low volumes. However, AM is a less mature technology compared to established manufacturing methods. This lack of maturity concerns especially the area of AM manufacturing constraints as the knowledge about them is limited and because they mature over time, as the technology evolves. The lack of knowledge hinders designers to fully take advantage of AM, fearing that the technology will affect product reliability. This situation is particularly emphasized in space components, since they are subject to high reliability requirements. In this paper, a methodology based on function decomposition and constraint modelling is proposed as a basis for re-design of products using AM. In the methodology, the original functions, design solutions and manufacturing constraints of a product are identified. Then, the original manufacturing constraints are removed and replaced with manufacturing constraints for AM. Afterwards, functions and design solutions on the function model are modified and a new part geometry is designed and eventually realised in CAD. This methodology has been applied on a case study featuring a satellite sub-component
Automatic geometry alteration when designing for metal additive manufacturing
No full textDuring the last decades, the aerospace industry has been interested in converting some of its production from traditional manufacturing to metal additive manufacturing. This technology is attractive to the aerospace industry due to the low production volumes and the need to minimize product mass that characterize the industry. The transition from traditional to additive manufacturing technologies requires designers to take heed of a new set of design and manufacturing constraints. A well-known limitation for the implementation of additive manufacturing is the need for support structures which increase material consumption and post processing time. The research presented in this paper suggests a novel algorithm for automatically altering the geometry of the product to reduce the need for support structures. The algorithm operates directly on the vertices of the 3D mesh by relocating them to mitigate overhang issues. A proof of concept in the form of a software prototype was developed using the Python programming language to demonstrate the algorithm, and how it can be applied to 3D models. The prototype software utilizes a 3D STL-file as input, and it outputs an altered file of the same format. In the process of developing the software prototype some issues surfaced, the most prominent of which was the inability of the algorithm to handle overhangs parallel to the substrate of the powder bed printer. Such overhangs are also referred to as 0°-overhangs due to their normal vector being parallel to the z-Axis, thus resulting in an overhang of 0°. Aside from that the algorithm also struggled with models of high complexity, which in some cases resulted in invalid or malformed STL geometries. The research conducted for this paper indicates that further research and development is required. Future research concerning automatic geometry alteration should focus on how to deal with the 0°-overhangs. It should also involve investigating the possibility to alter the geometry of CAD-models instead of STL-files, as CAD-models can contain more information, such as constraints. Information of that nature could enable the algorithm to take customer requirements into consideration as it alters the geometry, thus improving its ability to maintain product functionality
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