Local absorption of uncertainty in complex systems using resilient objects

Traditional approaches to managing uncertainties during product development often lead to increased complexity and resource consumption. This paper introduces the concept of ‘resilient objects’ as an alternative solution, designed to provide passive protection against disruptive events of different kinds, thereby reducing the necessity for complex margins at system interfaces. The paper illustrates the concept of resilient objects through practical examples, which demonstrate the objects’ ability to uphold system functionality even when faced with unexpected disruptive events. By embodying resilience locally in areas of the system that are most susceptible to uncertain conditions, resilient objects offer the potential to minimise interface margins and thus the need for excessive system over-design. The concept of resilient objects offers a new perspective on how to solve the trade-offs between resilience and complexity when addressing uncertainties in the dynamic landscape of product development

Design space exploration of a jet engine component using a combined object model for function and geometry

The design of aircraft and engine components hinges on the use of computer aided design (CAD) models and the subsequent geometry-based analyses for evaluation of the quality of a concept. However, the generation (and variation) of CAD models to include radical or novel design solutions is a resource intense modelling effort. While approaches to automate the generation and variation of CAD models exist, they neglect the capture and representation of the product’s design rationale—what the product is supposed to do. The design space exploration approach Function and Geometry Exploration (FGE) aims to support the exploration of more functionally and geometrically different product concepts under consideration of not only geometrical, but also teleological aspects. The FGE approach has been presented and verified in a previous presentation. However, in order to contribute to engineering design practice, a design method needs to be validated through application in industrial practice. Hence, this publication reports from a study where the FGE approach has been applied by a design team of a Swedish aerospace manufacturers in a conceptual product development project. Conceptually different alternatives were identified in order to meet the expected functionality of a guide vane (GV). The FGE was introduced and applied in a series of workshops. Data was collected through participatory observation in the design teams by the researchers, as well as interviews and questionnaires. The results reveal the potential of the FGE approach as a design support to: (1) Represent and capture the design rationale and the design space; (2) capture, integrate and model novel solutions; and (3) provide support for the embodiment of novel concepts that would otherwise remain unexplored. In conclusion, the FGE method supports designers to articulate and link the design rationale, including functional requirements and alternative solutions, to geometrical features of the product concepts. The method supports the exploration of alternative solutions as well as functions. However, scalability and robustness of the generated CAD models remain subject to further research

Cost-efficient digital twins for design space exploration: A modular platform approach

The industrial need to predict the behaviour of radically new products brings renewed interest in how to set up and make use of physical prototypes and testing. However, conducting physical testing of a large number of radical concepts is still a costly approach. This paper proposes an approach to actively use digital twins in the early phases where the design can be largely changed. The approach is based on creating a set of digital twin modules that can be reused and recomposed to create digital twin variants. However, this paper considers that developing a digital twin can be very costly. Therefore, the approach focuses on supporting the decisions about the optimal mix of modules, and about whether a new digital twin module should be developed. The approach is applied to an industrial case derived from the collaboration with two space manufacturers. The results highlight how the design of the modular platform has an impact on the cost of the digital twin, if commonality and reusability aspects are considered. These results point at the cost-efficiency of applying a modular approach to digital twin creation, as a means to reuse the results from physical testing to validate new designs and their ranges of validit

Connecting functional and geometrical representations to support the evaluation of design alternatives for aerospace components

Novel product concepts are often down-selected in favour of the incremental development of available designs. This can be attributed to the fact that for the development of a new product, simulations and analysis based on high-fidelity CAD models are required, which are expensive to create. To solve this problem, the use of a function model (FM) as intermediate step between ideation and embodiment is suggested. The approach has been examined in a case study with an aerospace company for the development of a turbine rear assembly, using multiple workshops and interviews with practitioners from the company. A multitude of novel solutions, even extending the functionality of the legacy design, were captured. The FM approach proved to support the representation, analysis, and configuration of 102 different concepts. Although supported by the FM model, the embodiment still showed to be a bottle neck for further development. The subsequent interviews with practitioners showed that the benefits of the approach were seen, but experienced as too complex. Further work will concern a more systematic connection between the FM and CAD model, in order to automate of the embodiment process

Function model-based generation of CAD model variants

A product is an artefact which fulfils a specific function. However, most design automation (DA) approaches wich are used to generate multiple alternative design concepts focus on the generation of CAD models. These neglect to represent the functional aspects of the product, and are furthermore deemed too rigid for the introductino of novel solutions. Pure function modellingappraoches on the other hand provides methods such as design rationale representation, introduction of novel solutions or instantiation of combinatorial alternative concepts, but the resulting models are insufficient for analysis. To alleviate this, a design space exploration (DSE) approach which couples function modelling and CAD is presented. The approachlinks the product’s design rationale modelled in enhanced functionmeans (EF-M) to a DA approach via the here introduced object model for function and geometry (OMFG). The resulting method is able to automatically generate CAD models of alternative concepts based on combinations of alternative design solutions defined in the function model. The approach is presented through a case study of an aircraft engine component. Sixteen different concepts are generated based on four functions with alternative solutions. In an initial computation of the effort to generate all alternative concepts, the DA aspect of the approach’s effort pays off as soon as five functions have two or more alternative solutions. Beyond the benefit of efficient instantiation of CAD models of alternative product concepts, the approach promises to provide the design rationale behind each concept, and thereby a more systematic way of exploring and evaluating alternative design concepts

Function modelling and constraints replacement for additive manufacturing in satellite component design

Additive 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

Design for test and qualification through activity-based modelling in product architecture design

Test and qualification (T&Q) phases take a significant portion of the time to market for critical products in the space industry, especially when introducing new technologies. Since T&Q are treated as standard procedures, they tend to be independent of the architectural design phases and kept away from design decisions. However, when introducing new technologies, qualification procedures may differ from those established in regular design scenarios, and the estimation of qualification costs and duration is problematic. There is a lack of design for qualification methods capable of modelling these activities in early phases and use those models to support the architecture design of products with affordable test and qualification phases. In this article, a computer-assisted, model-based design method to model T&Q activities concerning early product architecture designs is proposed. Product architecture alternatives, test schedules and cost are connected through the quantification of T&Q drivers and driver rates. The design method is demonstrated using a case study about electric propulsion for satellites. The method is applicable for design situations where the choice of technology has a strong dependence on the qualification procedure

Constraint Replacement-Based Design for Additive Manufacturing of Satellite Components: Ensuring Design Manufacturability through Tailored Test Artefacts

Additive 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

Designing and Integrating a Digital Thread System for Customized Additive Manufacturing in Multi-Partner Kayak Production

Additive manufacturing (AM) opens the vision of decentralised and individualised manufacturing, as a tailored product can be manufactured in proximity to the customers with minimal physical infrastructure required. Consequently, the digital infrastructure and systems solution becomes substantially more complex. There is always a need to design the entire digital system so that different partners (or stakeholders) access correct and relevant information and even support design iterations despite the heterogenous digital environments involved. This paper describes how the design and integration of a digital thread for AM can be approached. A system supporting a digital thread for AM kayak production has been designed and integrated in collaboration with a kayak manufacturer and a professional collaborative product lifecycle management (PLM) software and service provider. From the demonstrated system functionality, three key lessons learnt are clarified: (1) The need for developing a process model of the physical and digital flow in the early stages, (2) the separation between the data to be shared and the processing of data to perform each parties\u27 task, and (3) the development of an ad-hoc digital application for the involvement of new stakeholders in the AM digital flow, such as final users. The application of the digital thread system was demonstrated through a test of the overall concept by manufacturing a functional and individually customised kayak, printed remotely using AM (composed of a biocomposite containing 20% wood-based fibre)

Lifecycle design and management of additive manufacturing technologies

Additive manufacturing (AM) is being proposed as a revolutionary manufacturing technology, promising significant advantages both from a design and production perspective. One challenge is the disruptive nature of AM and its impact on all life cycle phases. This paper reports from a demonstrator project highlighting digitalization and process implications. A demonstrator tool was developed able to collectively capture and visualize different life cycle implications of AM products. Market expectations, technology characteristics and life cycle constraints were met in the demonstrator tool. Each individual part collected its own traceable data set, from design over manufacturing up to postproduction services. Key aspects demonstrated were 1) the need to represent any manufacturing and life cycle constraint already in design, 2) the need to integrate unique identifiers that build a digital twin and 3) the need to automate links between life cycle engineering steps