| 11. |
- Heshmati, Mohsen, 1987, et al.
(författare)
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Dependency of cohesive laws of a structural adhesive in Mode-I and Mode-II loading on moisture, freeze-thaw cycling, and their synergy
- 2017
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Ingår i: Materials and Design. - : Elsevier BV. - 1873-4197 .- 0264-1275. ; 122, s. 433-447
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, adhesive bonding has found its way to construction applications such as bridges. Given the harsh conditions that such structures are usually exposed to, it is necessary to account for environmental factors, particularly moisture and temperature, in the design phase. Cohesive zone modelling has attracted much attention in the last decade as a promising method to design adhesive joints. Despite this interest, the effects of moisture and thermal cycles on cohesive laws have not been investigated to the knowledge of the authors. In this paper, we present a method to directly measure the environmental-dependent cohesive laws of a structural adhesive loaded in pure Mode-I and Mode-II. Special consideration is given to overcome issues such as the time-consuming nature of moisture ingression and specimen dimensions, which could be problematic due to the size-limitations of conditioning equipment. The accuracy of this method was verified through simulation of the experiments using the finite element analysis. The effects of exposure to 95% relative humidity, immersion in saltwater and distilled water, and freeze-thaw cycles in the presence or absence of moisture were investigated. The results indicate the damaging effects of combined saltwater and freeze-thaw cycles which were clearly reflected on the shape of the cohesive laws.
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| 12. |
- Pradas Gómez, Alejandro, 1986, et al.
(författare)
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Design automation strategies for aerospace components during conceptual design phases
- 2023
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper explores the different design automation strategies used for the design of aerospace components. A literature review of the applicable strategies, together with the strategies used in the DEFAINE project are presented and compared. An opportunity to explore the combination of two strategies is presented (Enhanced Function-Mean and Knowledge Based Engineering), which has the potential to increase the discovery of novel design solutions while being able to assess their structural performance. The preliminary results of the combined strategy are presented, using a DEFAINE use case of a Turbine Rear Structure jet engine component.
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| 13. |
- Bergman, Martin, 1985
(författare)
-
Affective Surface Engineering for Product Design
- 2016
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Design research, sensation and perception, hard metrology, emotional functions, semantics, surface roughness, product interaction, core values, total appearance… the list of scientific phrases never ends. Yet, what do they mean and how shall we use it when we are communicating with the industry and our end users? Is it possible to link the product experience to process parameters, put a number onto it? When you can measure spoken needs or even better, implied needs, of a product, and relate that data to the production, it is possible do create advanced products with high interaction stimuli. By joining engineering sciences (hard metrology) with design science (soft metrology) correlations between customer’s product experience (emotional functions) and surface properties (technical functions) can be established.The research briefly handles an optimization process where the framework from Kansei Engineering (KE) is used to evaluate the semantics issues primarily regarding materials and functional surfaces of products. The basic idea is that; the stakeholder’s experience shall be observed already at the phase of ideation in the product development process, which then facilitates the project (in regard to the total appearance) later on when a concept reaches the production stage. The results presented in this thesis are carried out through a number of case studies together with the industry. The main result and aim of the research is a developed robust approach that links emotional functions with technical functions, which in the next step facilitates the improvement of the total appearance of a product. Nevertheless, it should be recognized that research is not yet complete. It is an iterative process, which confirms that the loop of the method needs to be complete. The developed method is a toolbox with the fundamental tools and workshops to facilitate the correlation process mentioned above, however the packaging of the final step in the method is not yet complete. The future research outlook will focus on the “independent industry implementation” where the method is used by the industry by guidelines only, thus without researchers support.
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| 14. |
- Berlin, Cecilia, 1981, et al.
(författare)
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Using the ACD3-ladder to manage multi-phase requirements on end-user products
- 2017
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Ingår i: Proceedings of the International Conference on Engineering Design, ICED. - 2220-4334 .- 2220-4342. - 9781904670872 ; 4:DS87-4, s. 425-434
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Konferensbidrag (refereegranskat)abstract
- During the development of any end-user product, a multitude of design decisions need to be made. But if design activities and decisions happen at the wrong time, or not at all, unintentional and sometimes negative design outcomes can be the result. Determining all requirements early in the product development is traditionally recommended, but may force design decisions to be made prematurely onthe basis of incomplete preconditions. Requirements at different degrees of resolution are useful and purposeful at different stages of the development process. To address these requirements management challenges, this paper proposes an approach for incrementally developing requirements in parallel with design, based upon a previously developed framework called ACD³, which draws on a combination of theoretically compatible ideas and concepts from Design Engineering, Human Factors/Ergonomics,Usability and Systems Theory. This approach helps designers identify and handle the possible interdependencies of design variables. The paper also theoretically motivates and demonstrates with an example how the different resolution levels of requirements relate within the framework.
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| 15. |
- Brahma, Arindam, 1987, et al.
(författare)
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A new model for capturing design information with an aim to aid change propagation assessment and subsequent redesign
- 2018
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Ingår i: DS 92: Proceedings of the DESIGN 2018 15th International Design Conference. - : Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Croatia; The Design Society, Glasgow, UK. - 1847-9073.
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Konferensbidrag (refereegranskat)abstract
- A new model is developed to investigate the causes of change propagation and guide the redesign process. The model offers a micro-level perspective on the mechanisms through which changes propagate or are absorbed. Extending the Information Structure Framework (ISF) reported by Ahmad et al. (2013), the model uses a multi-domain approach combined with a reformulated detail design process layer. It is illustrated through a desk-based case study of routine mechanical design. Advantages and limitations are discussed along with possibilities for further work.
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| 16. |
- Brahma, Arindam, 1987, et al.
(författare)
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Concepts of change propagation analysis in engineering design
- 2023
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Ingår i: Research in Engineering Design - Theory, Applications, and Concurrent Engineering. - : Springer Science and Business Media LLC. - 1435-6066 .- 0934-9839. ; 34:1, s. 117-151
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Tidskriftsartikel (refereegranskat)abstract
- Interest in change propagation analysis for engineering design has increased rapidly since the topic gained prominence in the late 1990s. Although there are now many approaches and models, there is a smaller number of underlying key concepts. This article contributes a literature review and organising framework that summarises and relates these key concepts. Approaches that have been taken to address each key concept are collected and discussed. A visual analysis of the literature is presented to uncover some trends and gaps. The article thereby provides a thematic analysis of state-of-the-art in design change propagation analysis, and highlights opportunities for further work.
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| 17. |
- Dabhilkar, Mandar, et al.
(författare)
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Supplier selection or collaboration? : Determining factors of performance improvement when outsourcing manufacturing
- 2009
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Ingår i: Journal of Purchasing and Supply Management. - : Elsevier BV. - 1478-4092 .- 1873-6505. ; 15:3, s. 143-153
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Tidskriftsartikel (refereegranskat)abstract
- An empirical study was designed to determine factors of performance improvement when outsourcing manufacturing. Findings from a survey of 136 manufacturing plants in Sweden show that most of them achieve their outsourcing motives, but not without trade-offs. Factors of performance improvements such as economies of scale or operations in low-cost countries can improve one performance dimension, such as product cost, yet negatively impact volume flexibility, speed or product innovation. The results show part characteristics and supplier operating capabilities are more important than supplier relationship strategies when outsourcing manufacturing, meaning that supplier selection trumps supplier collaboration in the make-or-buy decision.
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| 18. |
- Finnsgård, Christian, 1974
(författare)
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Assembly processes and materials supply systems design
- 2009
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lean production has over the last decades emerged as the most important paradigm for production, with the assembly processes in focus, including the objective to minimize non-value-adding work. Thus, much attention has been on the work of the assembly operator. However, little focus has been devoted to how the new requirements from lean production have been transformed into materials supply systems supporting the assembly processes. Hence, the purpose of this thesis is to contribute to increased knowledge about the relation between assembly processes and materials supply systems design.A framework is introduced in this thesis, describing how requirements from the assembly processes are transformed by the materials supply system into the actual materials flow. In the results of this thesis, a model structuring requirements in materials supply and assembly processes is proposed, tested, and subsequently different requirements were identified. Materials exposure is introduced as the transition from the materials supply system to the assembly system. Results show that that the materials exposure has a large impact on assembly workstations performance in terms of space needed, non-value-adding work and ergonomics. Further, an experiment showed that the materials exposure factors with the largest impact on picking time were packaging, angle of packaging and height above floor.Major contributions in this thesis are the identification and structuring of requirements in assembly processes and materials supply systems, and explaining how the materials exposure affects the assembly processes. How this knowledge can be applied in the design of new, or redesign of existing, production systems and materials supply processes in particular, is a managerial contribution.
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| 19. |
- Finnsgård, Christian, 1974, et al.
(författare)
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Impact of materials exposure on assembly workstation performance
- 2011
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Ingår i: International Journal of Production Research. - : Informa UK Limited. - 0020-7543 .- 1366-588X. ; 49:24, s. 7253-7274
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Tidskriftsartikel (refereegranskat)abstract
- This paper examines how the choice of materials exposure impacts workstation performance, in terms of non-value-adding work, space requirements and ergonomics. In a typical Swedish automotive setting, components are exposed in wooden pallets with frames beside the assembly line and supplied by forklift truck. In a case study, three workstations on an assembly line were studied and redesigned following the principles of lean production, using smaller plastic containers for the materials exposure. After the redesign, the space required for materials was reduced by 67%, non-value-adding work decreased by 20%, and walking distance was reduced by 52%. Furthermore, the ergonomics for the assembly operator improved greatly, with a 92% reduction of potentially harmful picking activities, thereby almost eliminating potentially harmful body movements. The theoretical contribution of this paper is firstly the development of an analysis model describing the impact of material exposure on workstation performance and secondly development of the existing categorization of work operations to include different materials handling activities. The most important managerial implication is an increased understanding of the relationship between space, ergonomics, non-value-adding work and materials exposure. These findings have direct implications on workstation design in industry.
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| 20. |
- Finnsgård, Christian, 1974
(författare)
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Materials exposure: The interface between materials supply and assembly
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis concerns the supply of components to assembly in production sys- tems, and introduces materials exposure as the interface between materials sup- ply systems and assembly systems. The purpose of the thesis is to explain how materials exposure influences the performance of materials supply systems and assembly systems. The supply of components is crucial for assembly, for in serving the requirements from assembly. Still, the materials supply system has to remain efficient. In this way, materials exposure impacts the performance of a production system as a whole.The thesis is a based on five studies, all of which depart from theoretical frame- works developed from literature and empirically applied within the Swedish automotive industry. Four case studies and one experiment were conducted to answer three research questions, and the results are published in five papers.The results of the thesis provide several theoretical and practical contributions. Both the position of the exposure and the size of the packaging for a component impact the performance of the assembly workstation performance in terms of space required, non-value-adding work, and ergonomics. Materials exposure impacts manual picking time at assembly lines, for which packaging is the most influential factor, followed by angle of exposure and height of the exposed com- ponent. Materials exposure further impacts the configuration of the in-plant ma- terials supply system by requiring additional activities in the in-plant materials supply system, which impacts its performance. Concerning the impact of choice of packaging used in materials exposure, a model to evaluate the impact a pack- aging has on the performance of the materials supply system was developed. The Materials Flow Mapping methodology is another contribution that describes the activities in materials supply systems, as well as categorises the activities in material flows into materials handling, transportation, storage, and administra- tive activities.This thesis explains how the materials exposure influences the performance of materials supply systems and assembly systems. It shows how materials expo- sure impacts the assembly system performance and the in-plant materials supply system performance, and finally, how the packaging for materials exposure im- pacts the performance of the materials supply systems and assembly systems. The thesis can further be used as a guide for how materials should be exposed and in the selection of packaging for materials exposure. The most beneficial managerial use would be in the design and operation of assembly systems, mate- rials supply systems, and in particular, materials exposure.
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