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- Hatami, Sepehr, 1981, et al.
(author)
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Optimised selection of processing routes for sintered parts manufacture: A component-oriented approach
- 2009
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In: Advances in Powder Metallurgy and Particulate Materials - 2009, Proceedings of the 2009 International Conference on Powder Metallurgy and Particulate Materials, PowderMet 2009. - Princeton, N.J. : Metal Powder Industries Federation. - 9780981949611 ; , s. 139-1323
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Conference paper (peer-reviewed)abstract
- To stay competitive, PM manufacturers have to be able to accept a wide range of components with different features and properties. Thus, it is of utmost importance for manufacturers to adapt their common process routes to new requirements as rapidly and economical as possible. The procedure of identifying the right route among all the alternatives requires abundance of experience and knowledge and is a crucial and time-consuming decision; usually made by a team of engineers. In this study, by considering the mechanical properties and design specifications of the final component, a simple methodology is developed to aid the engineer(s) in selection of the optimum PM process route. In order to sort the possible routes according to cost, a cost estimating module has been devised. The total concept is applied to a case study and its accuracy has been evaluated.
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| 4. |
- Stolt, Roland, 1970-
(author)
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An Automated Design and Advisory System for Pressed-and-Sintered Powder Metallurgy Parts
- 2008
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In: Proceedings of the 2008 World Congress on Powder Metallurgy & Particulate Materials, June 8–12, Washington, D.C. United States. - Princeton, NJ, United States : MPIF.
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Conference paper (peer-reviewed)abstract
- The aim of the present paper is to dissolve the bottleneck for PM market expansion caused by lack of knowledge among designers about PM-specific design principles by proposing an automated PM-part advisory system. The system, called PM-Wizard, checks that a PM-part design suggestion represented as any 3D solid CAD-model complies with the geometrical design rules and recommendations for PM-parts. The system consists of a rule-base hosted by a modern commercial CAD/CAE-system and a programmed algorithmic procedure that converts the design suggestion into a specially developed format. The format enables the automated evaluation of the PM-part in the receiving CAD/CAE-system informing the designer on how the geometry should be revised to facilitate the pressing. The conversion algorithm has been tested on a large number of PM-parts, and the result is that all the tested parts can be converted into the proposed format and successfully evaluated.
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| 6. |
- Stolt, Roland, 1970-
(author)
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CAD-Model Parsing for Automated Design and Design Evaluation
- 2008
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Doctoral thesis (other academic/artistic)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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| 7. |
- Stolt, Roland, 1970-
(author)
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Identifying Features in Cad-Models for Powder Metallurgy Component Evaluation
- 2008
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In: Proceedings of the Design 2008, 10th International Design Conference. - 9789536313891 ; , s. 689-696
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Conference paper (peer-reviewed)abstract
- This paper presents a newly developed CAD-integrated system for the manufacturability evaluation of designs of powder metallurgy (PM) pressed and sintered parts. The contribution of the paper is the automated reconstruction of a specialized construction history tree from any CAD-model directly in the receiving CAD-system. The reconstruction is based on the geometrical restrictions of the shapes that can be manufactured by the PM process. This facilitates the creation of a transparent and user-revisable rule-base to evaluate the parts manufacturability, which is shown. It will enable designers to get feedback on their designs, reducing the number of design loops with the PM-parts supplier needed before the parts geometry can be established.
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| 8. |
- Stolt, Roland, 1970-
(author)
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Managing Product and Process Knowledge in CAD-Systems
- 2009
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In: NordPLM'09. - Göteborg : Chalmers University of Technology. - 9789197507974 ; , s. 51-61
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Conference paper (peer-reviewed)abstract
- In order to codify, manage, and reuse the knowledge gained from pursing product development projects, CAD-programs have started to provide functionality for supporting this activity. Since the primary purpose of the CAD program is to interactively define geometry, the functionality has been integrated primarily to be used on the parameters of the CAD-model of the design instance. This paper explores how the functionality can be used in a broader scope, managing and automatically reusing knowledge for all designs intended for a certain production process. This is facilitated by automatically converting an arbitrary CAD-model of a design to a format that is accessible for knowledge handling and reuse functionality in the CAD-system. A conversion algorithm for the processes die-casting and powder metallurgy pressing sintering is presented, as well as showing how the knowledge can be represented in the CAD-system. This will allow engineers to actively participate in the knowledge build-up and insure that the general knowledge can be handled in the companies’ IT-infrastructure.
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