| 1. |
- Amen, Rafael, et al.
(författare)
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Matching Design Tasks To Knowledge Based Software Tools
- 1999
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Ingår i: Proceedings of the 1999 ASME Design Engineering Technical Conferences.. - New York : American Society of Mechanical Engineers.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Amen, Rafael, et al.
(författare)
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Solidhandboken
- 1996
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Rapport (populärvet., debatt m.m.)
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| 3. |
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| 4. |
- Cederfeldt, Mikael, 1975, et al.
(författare)
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Solid Modelling With Dimensional and Topological Variability
- 2003
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Ingår i: ICED03. - Glasgow : The Design Society.
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Konferensbidrag (refereegranskat)abstract
- With the advent of commercial solid modelling systems some fifteen years ago the opportunity for three-dimensional parametric geometry was opened to industry. Today solid modelling systems are the dominating CAD tool among advanced engineering companies, but despite the time and money saving implications, industry has been slow to exploit the parametric capabilities of these systems.One reason for the slow adoption of parametric modelling is that originally many solid modellers suffered from lack of stability under parametric changes. This situation is now changed and if a model in a modern CAD system collapses, this is usually due to modelling deficiencies rather than numerical failures. Straightforward dimensional variations rarely cause any problems, but to fully exploit the parametric capability for complex features with a variable topology, there is a need for a systematic approach to build stable and purposeful parametric models.The purpose of this work is to discuss how different modelling approaches relate to the ease of use and robustness of the CAD model in terms of creating variants and product families. We use the term Design for Variability, DFV, for a modelling approach that ensures that parametric models are well suited for variation design.
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| 5. |
- Elgh, Fredrik, 1971, et al.
(författare)
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An Automated Cost Estimating System for Variant Design Based on the Method of Successive Calculus
- 2003
-
Ingår i: ICED03.
-
Konferensbidrag (refereegranskat)abstract
- For many products the adaption to customer specifications is essential and requires flexible product design and manufacture while maintaining competitive pricing. A large category of design work in industry has the character of redesign of an existing product concept in terms of dimensional changes, topology variations and configuration of components. In order to evaluate design proposals, costs, which are controlled by the product design, selected materials and manufacturing processes, need to be estimated. Cost estimates are normally based on the manufacturing process plans, which can only be formed when production preparation is finalised. The widespread industrial use of solid modelling opens up new possibilities to automate this process. The purpose of this work is to demonstrate and test a method to extract product information from a CAD model to allow process planning and cost calculation to be carried out automatically for a given class of products. With such a system cost estimates can be made available to the designer the instant a design proposal has been presented. This allows for design iterations to be carried out in order to govern the design work towards solutions with an optimal balance between product and production properties.
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| 6. |
- Elgh, Fredrik, et al.
(författare)
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An Automatic Cost Estimating System for Variant Design Based on the Method of Successive Calculus
- 2003
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Ingår i: Research for Practice - Innovations in Products, Processes and Organisations. - Glasgow : The Design Society. - 1904670008
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Konferensbidrag (refereegranskat)abstract
- For many products, the adaption to customer specifications is essential and requires flexible product design and manufacture while maintaining competitive pricing. A large category of design work in industry has the character of the redesigning of an existing product concept in terms of dimensional changes, topology variations and the configuration of components. In order to evaluate design proposals, costs, controlled by the product design, selected materials and manufacturing processes, need to be estimated. Cost estimates are normally based on the manufacturing process plans. They, in turn, can only be formed when production preparation is finalised. The widespread industrial use of solid modelling opens up new possibilities for automating this process. The purpose of this work is to demonstrate and test a method of extracting product information from a CAD model in order to allow process planning and cost calculation to be carried out automatically for a given class of products. With such a system, cost estimates can be made available to the designer the instant a design proposal has been presented. This allows design iterations to be carried out, in order to govern the design work towards solutions with an optimal balance between product and production properties.
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| 7. |
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| 8. |
- Elgh, Fredrik, et al.
(författare)
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An Ontology Approach To Collaborative Engineering For Producibility
- 2007
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Ingår i: International Journal of e-collaboration. - 1548-3673 .- 1548-3681. ; 3:4, s. 21-45
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Tidskriftsartikel (refereegranskat)abstract
- With today’s high product variety and shorter life cycles in automobile manufacturing, every new car design must be adapted to existing production facilities so that these facilities can be used for the manufacturing of several car models. In order to ensure this, collaboration between engineering design and production engineering has to be supported. Sharing information is at the core of collaborative engineering. By implementing an ontology approach, work within domains requirement management, engineering design and production engineering can be integrated. An ontology approach, based on an information model implemented in a computer tool, supports work in the different domains and their collaboration. The main objectives of the proposed approach are: supporting the formation of requirement specifications for products and processes, improved and simplified information retrieval for designers and process planners, forward traceability from changes in product systems to manufacturing systems, backward traceability from changes in manufacturing system to product systems, and the elimination of redundant or multiple versions of requirement specifications by simplifying the updating and maintenance of the information.
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| 9. |
- Elgh, Fredrik, et al.
(författare)
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Collaborative Engineering for Enhanced Producibility by Ontology-based Integration of Design and Production
- 2009
-
Ingår i: Virtual Team Leadership and Collaborative Engineering Advancements. - Hershey : Information Science Reference. - 9781605661100
-
Bokkapitel (refereegranskat)abstract
- Many companies base their business strategy on customized products with a high level of variety and continuous functional improvements. For companies to be able to provide affordable products in a short time and be at the competitive edge, every new design must be adapted to existing production facilities. In order to ensure this, collaboration between engineering design and production engineering has to be supported. With the dispersed organisations of today combined with the increasing amount of information that has to be shared and managed, this collaboration is a critical issue for many companies. In this article, an approach for sharing and managing product and production information is introduced. The results are based on the experiences from a case study at a car manufacturer. By ontology-based integration, work within domains engineering design, production engineering and requirement management at the company was integrated. The main objectives with the integration were: support the formation of requirement specifications for products and processes, improve and simplify the information retrieval for designers and process planners, ensure traceability from changes in product systems to manufacturing systems and vice versa, and finally, eliminate redundant or multiple versions of requirement specifications.
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| 10. |
- Elgh, Fredrik, et al.
(författare)
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Ontology Based Management of Designer's Guidelines for Motorcar Manufacture
- 2006
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Ingår i: Challenges in collaborative engineering CCE’06 - State of the Art and Future Challenges in Collaborative Design. - Jönköping : Department of Computer & Electrical Engineering, School of Engineering. - 919756043X ; , s. 71-83
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Konferensbidrag (refereegranskat)abstract
- With today’s high product variety and shorter life cycles in motor car manufacture, every new car design must be adapted to existing production facilities so that these can be used for several car models. Sharing information is at the core of collaborative engineering. With an ontology approach, the work within the domains requirement management, engineering design and production engineering can be integrated. An ontology approach based on an information model implemented in a computer tool supports the work in the different domains and their collaboration. In our work we make use of the existing structures and link those using appropriately named links. We also propose the introduction of a new structure describing the generic functions of the manufacturing system, MSF. This tree structure is a suitable tool to link product related objects to their associated production equipment at varying levels of detail. The manufacturing requirements are modelled using a concept for the definition of the requirement content, called Manufacturing Requirement (MR). To enable the MR to cover different ranges and levels, and enhance the maintenance of the system integrity, the concept of Requirement Object is introduced. The RO is used to collect the instances for which a specific MR is valid. We also use the rule inference facility to reduce the number of explicitly defined relations.
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| 11. |
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| 12. |
- Harrysson, U, et al.
(författare)
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FEM/BEM
- 1990
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Rapport (populärvet., debatt m.m.)
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| 13. |
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| 14. |
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| 15. |
- Johansson, Joel, 1978-
(författare)
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Automated Computer Systems for Manufacturability Analyses and Tooling Design : Applied to the Rotary Draw Bending Process
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Intensive competition on the global market puts great pressure on manufacturing companies to develop and produce products that meet requirements from customers and investors. One key factor in meeting these requirements is the efficiency of the product development and the production preparation processes. Design automation is a powerful tool to increase efficiency in these two processes. The benefits of automating the manufacturability analysis process, a part of the production preparation process, are shortened lead-time, improved product performance, quality assurance, and, ultimately, decreased costs. Further, automation is beneficial as it increases the ability to adapt products to new product specifications with production preparations done in a few or in a single step. During the automation process, knowledge about the manufacturability analysis process is collected and stored in central systems, thus allowing full control over the design of production equipments. Topics addressed in this thesis include the flexibility of design automation systems, knowledge-bases containing alternative design rules, the automation of the finite element analysis process, manufacturability analysis over several productions steps, and the determination of production limits by looping the automated manufacturability analysis process. These topics are discussed in connection with the rotary draw bending of aluminum profiles. It is concluded that the concept of design automation can be applied to the manufacturability analysis process at different levels of automation depending on the characteristics of the implemented knowledge. The concept of object orientation should be adapted when implementing a knowledge-base and when developing the geometrical representations of the products. This makes a design automation system flexible enough to edit underlying knowledge and to extend the targeted design space. It is possible to automate the process of setting up, running, and interpreting finite element analyses to a great extent, enabling the design automation system to evaluate its own design proposals. It is also possible to enable such systems to consider sequences of manufacturing steps and loop them to develop decision support guiding engineers early in the design process, saving time and money while still assuring high product quality.
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| 16. |
- Johansson, Joel, et al.
(författare)
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Automated design of rotary draw bending tools : an approach based on generic CAD-models driven by heuristic and algorithmic knowledge
- 2006
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Ingår i: International conference on efficient development of manufacturing machines and processes, 2006, Wroclaw, Poland. ; 6:3, s. 86-96
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Konferensbidrag (refereegranskat)abstract
- For parts suppliers in the manufacturing industry the process of preliminary production preparation and subsequent calculation of offers are critical business activities. A vital part of production preparation is the design of fixtures and tooling necessary for many processes of metal forming. For a company to give quick responses to customer enquiries, or changes in prior specifications, it would be highly beneficial with a degree of automation in this design process. This implies the development of a computer based system able to capture existing design procedures and associated knowledge for the classes of tooling required for the forming process. In this work we exemplify an automated design system for tooling by an implementation for rotary draw bending of aluminium tubing. The system is based on established design practice and heuristic knowledge developed over many years of practical experience. The system will evaluate whether a given specification is producible with existing materials and equipment, select suitable machine, determine process parameters and determine type and dimensions of components of form die, clamp die, follower or pressure die, wiper and mandrel. The system is built on readily available commercial software packages. When building a system of this kind it is essential that the knowledge documentation and structure is such that the functions of the system can be easily understood by the users of the system and by future developers. Aspects of user friendliness, transparency and scalability are addressed in the summary of this paper.
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| 17. |
- Johansson, Joel, 1978-
(författare)
-
Design Automation Systems for Production Preparation : Applied on the Rotary Draw Bending Process
- 2008
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Intensive competition on the global market puts great pressure on manufacturing companies to develop and produce products that meet requirements from customers and investors. One key factor in meeting these requirements is the efficiency of the product development and the production preparation process. Design automation is a powerful tool to increase efficiency in these two processes. The benefits of automating the production preparation process are shortened led-time, improved product performance, and ultimately decreased cost. Further, automation is beneficial as it increases the ability to adapt products to new product specifications with production preparations done in few or in a single step. During the automation process, knowledge about the production preparation process is collected and stored in central systems, thus allowing full control over the design of production equipments. Three main topics are addressed in this thesis: the flexibility of design automation systems, knowledge bases containing conflicting rules, and the automation of the finite element analysis process. These three topics are discussed in connection with the production preparation process of rotary draw bending. One conclusion drawn from the research is that it is possible to apply the concept of design automation to the production preparation process at different levels of automation depending on characteristics of the implemented knowledge. In order to make design automation systems as flexible as possible, the concept of object orientation should be adapted when building the knowledge base and when building the products geometrical representations. It is possible to automate the process of setting up, running, and interpreting finite element analyses to a great extent and making the automated finite element analysis process a part of the global design automation system.
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| 18. |
- Nergård, Henrik
(författare)
-
Knowledge engineering models as experience carriers
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Today’s manufacturing industry is experiencing an increased competitive environment due to the effects of market globalisation. To stay competitive there has been an increased interest in providing Total Offers, Integrated Product Service Offerings, Functional Products, commonly known as Product Service Systems. The development of Functional Products enhances the pressure on cross-disciplinary design work, concerned with integrating hardware and service development into the same development process, i.e. the Functional Product Development (FPD) process. In the FPD context of enhanced collaboration, engineering knowledge management has gained increased attention. Today, most of the experience is documented in plain text, such as white-papers and lessons learned. Text and design and decision support tools, such as those presented in the demonstrators, are built upon facts and explicit knowledge that support thinking-first, but can these tools also support seeing-first and doing-first? This means that the focus of creating tools to support the design process also includes aspects that support transfer of knowledge and experience, thus widening the purpose of the methods. The thesis examines how tools developed with the purpose to capture and formalize engineering design knowledge and thus support the design process can support experience feedback within product development organizations. The results present issues to consider when performing functional product development. Intellectual Property issues regarding what information to share and with whom become important in an extended enterprise setting. Design support tools intended for use between partners in the extended enterprise need to consider these questions to not loose core-knowledge to partners and competitors. Design support tools used in the early design phases, when developing total offers or conducting functional product development, need to consider knowledge from diverse disciplines to examine how life cycle aspects are affected through design decisions and vice versa. When creating total offers, i.e. Functional Products, there is a need to understand which state the product development process for the total offer is in. In an attempt to create a visual tool that shows the Total Offer Readiness Level (TORL) for the product development process a demonstrator has been developed. The use of agent-based modelling to create the activities that constitute the design process seems as a promising approach to realizing a dynamic TORL. Communicating knowledge and experience within an organization is not an easy task. It is discussed that approaches such as those described in the results section (KBE, Agent-based modelling and decisions support tools that visualize life cycle aspects (TORL)) could be used in experience feedback because to that they support thinking-, seeing- and doing-first, the three approaches to decision-making. However, most experience is presently hidden within formalized computer code, i.e. Knowledge Based Systems, making it difficult to interpret for persons other than the developer. If the goal is to reuse the design and decision support tool itself (in the way KBS are used) for experience feedback, nothing changes. However, if knowledge and experience implemented in the tool become more transparent (easier to see the connection between computer code and the rationale to how it became) to the user, the design and decisions support tools would increase the learning effect and parts of the knowledge implemented could be used in other projects. The thesis has contributed to an increased understanding of how KBE (Knowledge Based Engineering) can be used in design support tools that have been implemented with multi-disciplinary knowledge and information. Further KBE tools can be used to support cross-company collaboration between partners in the extended enterprise, since design and analysis processes have been automated and an interface for collaboration between partners has been accomplished. The use of agent-based modelling to create models that describe product development activities from a micro-level perspective and thus support the realization of a TORL has been investigated further. It is concluded that tools and methods as presented in this thesis and the papers can support knowledge and experience transfer if they are completed with aids that support thinking-first, seeing-first and doing-first effect.
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| 19. |
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| 20. |
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| 21. |
- Rask, I, et al.
(författare)
-
Designer's Pilot : Introducing a Knowledge System for DFM
- 2003
-
Ingår i: Proceedings of the EVEN Conference on Virtual Engineering Applications for Design and Product Development. - Loughborough : Loughborough University. - 0947974156
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Konferensbidrag (refereegranskat)
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| 22. |
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| 23. |
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| 24. |
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| 25. |
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| 26. |
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| 27. |
- Raudberget, Dag, et al.
(författare)
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EXPERIENCES OF SET BASED CONCURRENT ENGINEERING IN FOUR PRODUCT DEVELOPING COMPANIES
- 2010
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Ingår i: Proceedings of the TMCE 2010, April 12–16, 2010, Ancona, Italy.
-
Konferensbidrag (refereegranskat)abstract
- This paper describes experiences from implementation of Set-Based Concurrent Engineering in four different product developing companies. The objective was to investigate if the principles of Set-Based Concurrent Engineering can improve the efficiency and the effectiveness of the development process in industrial cases, but also to identify barriers for its implementation. The study shows that set-based projects can be driven within an existing organization, given the proper support. The participants claim that a set-based approach gives positive effects on development performance, especially on the level of innovation, product cost and performance. The improvements were achieved at the expense of slightly higher development costs and longer lead time. However, the positive effects are dominating and the companies involved intend to use Set-Based Concurrent Engineering in future projects when appropriate.
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| 28. |
- Raudberget, Dag
(författare)
-
Industrial Experiences of Set-based Concurrent Engineering- Effects, results and applications
- 2012
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- During product development, most of the customer value, as well as the cost and the quality of a product are defined. This key role of development in industry has led to an intense search for better ways to develop products, software, services and systems. One development methodology that has received positive attention is Set-Based Concurrent Engineering (SBCE). Some authors claim that SBCE and related practices from Lean Development are four times more productive than traditional development models. Unfortunately, SBCE is also described as hard to implement. This thesis presents the results of a three year research project aimed at implementing and describing the effects of Set-Based Concurrent Engineering in industry. The scope of the research is to use the principles of SBCE as a means to improve the productivity of industrial product development processes and its resulting products. The contribution of this work is a better understanding of Set-Based Concurrent Engineering and a support to implement its principles. The results show that SBCE gives positive effects on many aspects of product development performance and on the resulting products. The improvements are especially dominant on product performance, product cost and the level of innovation Moreover, a comparison between a Set-based decision process and a traditional matrix for design evaluation is presented, showing that these two approaches generate different results. The matrix evaluation promoted the development of new technology and the Set-based process promoted a thorough understanding of the important design parameters of the current designs. Finally, this work presents a structured design process and computer tool for implementing the principles of SBCE. The process was demonstrated by using information from an industrial development project, showing how the proposed process could implement the three principles of SBCE in a traditional Point-based development environment.
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| 29. |
- Stolt, Roland, et al.
(författare)
-
Automatic preparation of CAD-generated solid geometry for FE-meshing
- 2005
-
Ingår i: NAFEMS World Congress 2005. ; , s. 101-
-
Konferensbidrag (refereegranskat)abstract
- In recent years the computing power and meshing algorithms have developed to a state where FEA problems can often be solved directly using the solid geometry. However for complex geometry and complicated calculations there will for the foreseeable future be a need for geometrical idealizations.To reduce the time spent on making geometrical idealizations in repetitive FEA, a CAD-integrated KBES (Knowledge Based Engineering System) has been developed. The KBES creates a surface idealization from a thin-walled solid by utilizing generic modelling knowledge and by registering information about the CAD-specific features which the designer uses to define the solid geometry. From this information a corresponding surface idealization is created in the same CAD-system. This allows an updated and parametric geometry idealization of the complete CAD-geometry to be created with a degree of automation directly in the CAD-system.Primarily the mid-surfaces oriented in the tooling draft direction are created by evaluating the sketches which the features of the CAD-model are based on. The KBES also trims the created surfaces, thus facilitating the subsequent meshing.The KBES has been developed in CATIA V5 (Dassault systemes). It contains rules defined in CATIA knowledgeware which trigger sequential routines written in VBA (Visual Basic for Applications). An industrial application example where the system is used to automatically create a surface idealization for a die-cast part is also presented.
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| 30. |
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| 31. |
- Stolt, Roland, 1970-
(författare)
-
CAD-Model Parsing for Automated Design and Design Evaluation
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Product development has both innovative and analytic sides. Starting from the requirements, a design suggestion is generated. In order to assess how well the envisioned design fulfils the requirements, it is sometimes necessary to build a computer model of it for the analysis. The overall motivation of the work presented is to reduce the time spent on creating the model by reusing knowledge gained from developing similar products by suggesting, building and evaluating IT-systems. To verify the systems real design examples, obtained from companies that have participated in the research projects have been used. The work is based on two major application examples. The first, involving the automated geometrical idealisation of die-cast parts (Paper I-III), and the second involving manufacturability of powder metallurgy pressed and sintered parts (Paper IV-VI). The work starts from the point in the product development process where it exists a design suggestion represented as an arbitrary format CAD-model. In the powder metallurgy case the object is to secure that the geometry is suitable for the production process. In the die-casting case the object is to automatically create an idealised version of the model for shell elements meshing. These two tasks have previously been treated as two separate cases, addressed by completely different software. This thesis suggests a common method for addressing the two cases. The method is based on converting the CAD-models, using the geometrical restrictions of the production processes, into a format with a specialised feature structure, parameterisation and construction history using a feature recognition approach. The features are then automatically reconstructed in a target CAD-system. The resulting, specialised CAD-model can be used for automated design and design evaluation purposes, demonstrated in the thesis. The models are therefore called DAR (Design Automation Ready)-models. The DAR-models are useful in that they separate the conversion from the subsequent treatment of the models providing modularisation, flexibility and user insight in the model structure. In that a construction history and parameterisation have be constructed in the target CAD-system, the advanced geometry manipulation and means for knowledge management often provided in modern CAD-systems can be accessed in a transparent and user manageable way. This extends the usefulness of the CAD-systems from involving only interactive work to managing all components sharing the same production process.
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| 32. |
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| 33. |
- Sunnersjö, Staffan, et al.
(författare)
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A Transparent Design System for Iterative Product Development
- 2006
-
Ingår i: Journal of Computing and Information Science in Engineering. - : ASME International. - 1530-9827 .- 1944-7078. ; 6:3, s. 300-307
-
Tidskriftsartikel (refereegranskat)abstract
- Automated systems for variant design can be used for design iterations in order to guide the designer towards solutions that are optimized with respect to weight, cost, lead time, or other vital properties. In this work such a system for computational design problems is presented together with examples of its application. The system performs design computations, computed aided design model configuration, production process planning, and cost estimation. The design rules and algorithms are captured in knowledge "chunks," which are human readable as well as computer executable. The workflow governing the execution of these rules and algorithms is created using a dependency structure matrix (DSM) which is included in the system. Particular attention has been given to the need for transparency, modularity, and longevity of the system, which is a prerequisite for such a system to become a viable tool in industrial applications. Experiences from the proposed system indicate that the DSM workflow manager in combination with a human readable and modularized knowledge base provides clarity and transparency for both developer and user of the system.
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| 34. |
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| 35. |
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| 36. |
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| 37. |
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| 38. |
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| 39. |
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| 40. |
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| 41. |
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| 42. |
- Sunnersjö, Staffan
(författare)
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Framtidens konstruktionsarbete
- 1991
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Ingår i: Uppfinnaren & konstruktören. - 0284-9682. ; :2
-
Tidskriftsartikel (populärvet., debatt m.m.)
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| 43. |
- Sunnersjö, Staffan
(författare)
-
Från Leonardo till NURBS
- 1997
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Ingår i: Uppfinnaren/Konstruktören. ; :2
-
Tidskriftsartikel (populärvet., debatt m.m.)
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| 44. |
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| 45. |
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| 46. |
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| 47. |
- Sunnersjö, Staffan, 1948, et al.
(författare)
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Hydrodynamic inertia and damping of ship hull vibrations
- 1988
-
Ingår i: Transactions of the Royal Institute of Naval Architects. - 0035-8967. ; 130, s. 107-117
-
Tidskriftsartikel (refereegranskat)abstract
- The entrained water plays an important role in ship hull vibrations. The classic Lewis method for calculation of hydrodynamic added mass has some inherent shortcomings that can result in insufficient accuracy, particularly for higher order modes. This is essentially due to the fact that the Lewis method uses a diagonal mass matrix that is dependent on the mode of vibration, while the physical reality is more accurately represented by a mode-independent, full mass matrix. Such full mass matrices can be calculated with Finite Volume or Source- Sink methods, which, however, require extensive computer calculations with detailed input data. A method is presented with which the Lewis transform can be used to determine a full mass matrix and gives very good agreement with Finite Volume calculations for a test case on a small ship. The Finite Volume calculations have also been used to study damping …
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| 48. |
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| 49. |
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| 50. |
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