| 1. |
- Babaahmadi, Arezou, 1985, et al.
(författare)
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Development of an electro-chemical accelerated ageing method for leaching of calcium from cementitious materials
- 2016
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Ingår i: Materials and Structures. - : Springer Science and Business Media LLC. - 1359-5997 .- 1871-6873. ; 49:1-2, s. 705-718
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Tidskriftsartikel (refereegranskat)abstract
- To facilitate the long term durability predictions of nuclear waste repositories, acceleration methods enhancing calcium leaching process from cementitious materials are needed, even though mechanisms not necessarily comparable to those predominant in a natural leaching process may be developed. In the previously published acceleration methods the samples are very small, which limits further physical or mechanical tests. In this paper, a new acceleration method based on electro-chemical migration is presented. The method although not driven with the same kinetics as in natural leaching, was designed in such a way that unnecessarily destructive by-effects could be minimized while promoting a higher leaching rate for a sample size suitable for further testing the mechanical and physical properties. It is shown that approximately 1x10^6 C of electrical charge per paste specimen of size Ø50 x 75 mm (approximately 230 g) is required to leach out the total amount of Portlandite. The chemical and mineralogical properties of leached samples are characterized by various techniques. It is concluded that aged samples are comparable to those leached in a natural leaching process as both are characterized by a layered system comprising an unaltered core delineated by total dissolution of Portlandite followed by a progressive decalcification of the calcium silicate hydrate gel.
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| 2. |
- Frödin, Kerstin
(musiker, creator_code:cre_t)
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Ska alla tecken låta? : Konsertprojekt med tre uruppföranden av svensk musik i iscensättning av Karl Dunér med ensemble Lipparella
- 2016
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Konstnärligt arbete (refereegranskat)abstract
- I projektet Ska alla tecken låta? framförde ensemblen Lipparella tre nyskrivna kompositioner av Per Mårtensson, Lisa Streich och Erik Peters. Den ”klassiska konserten” i en traditionell konsertsal förändras alltmer och ensemblen sökte med projektet nya former för närhet och dynamik i rummet mellan publiken och verken. Med projektet ville ensemblen erbjuda publiken ett spektrum av möjliga ingångar till de musikaliska och litterära verken, i lyssnandet, förståelsen och upplevelsen. Regissören Karl Dunér utvecklade det sceniska konceptet som anpassades efter olika rum och miljöer och utnyttjade olika lokalers egenart i helhetsupplevelsen.Lipparella:Mikael Bellini - kontratenorAnna lindahl - violinKerstin Frödin - blockflöjtLouise Agnani - viola da gambaPeter Söderberg - teorbSpelplatser: Baertlings foajé i första Hötorgshuset - 18 september 2016Svindersviks Paviljong i Nacka - 22 september 2016Färgfabriken - 29 september 2016Rönnells antikvariat - 13 oktober 2016Finansiärer:Statens Musikverk (projektbidrag) Diarienummer 1102/15 och Kulturrådet (samarbete med tonsättare) Projektnummer: 2014/5190
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| 3. |
- Mårtensson, Per, 1976-
(författare)
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Framework for cost and weight efficient conceptual design of automotive composite body structures
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The automotive industry is facing a great challenge - reducing the weight of their vehicles. Carbon fibre composites are regarded by many as the only real option as traditional engineering materials are now running out of potential for further weight reduction. In this doctoral thesis a framework is presented which will provide guidelines for the conceptual phase of the development of an automotive composite body structure. The framework is initiated by defining ideal material diversity, as well as initial partition of the body structure based on process and material selection. Then, a further analysis of the structures is made in order to evaluate whether a more cost efficient solution can be found by further dividing the structure. Such a differential design approach is analysed in the third part of the work, studying both the financial and structural effects of such partitioning. In order to increase the understanding of the intimate relationship between design, material and manufacturing process, balancing manufacturing and structural optimization is addressed. Finally, drape simulation tools are used to assess the geometric complexity of composite structures in order to further quantify suitable split lines in cases of differential design approach.Different carbon fibre composite material systems and processes are compared and evaluated in the work. The results show that a high-performance material system with continuous fibres is both more cost and performance effective as compared to industrialised, discontinuous fibre composites. Further analysis shows the importance of balancing the design for manufacturing and the structural weight optimization of the structures in order to reach a cost and weight effective design. When restricting composite design freedom with manufacturing constraints, the great benefits of structural composites disappear and with this both weight and cost effectiveness.
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| 4. |
- Knutsson, Rickard, et al.
(författare)
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Bio-Agro Defense Collaboration : The Need of Joint Leadership Education and Training of Strategic Analysts and Decision Makers
- 2015
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Ingår i: Journal of Defense Resources Management. - : OMICS Publishing Group. - 2068-9403 .- 2247-6466 .- 2167-0374. ; 5:2
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Forskningsöversikt (refereegranskat)abstract
- Bioweapons deliberately spread to humans and animals is one of the most complex and intersectoral CBRNE threats. It requires multi-sectoral collaboration between law enforcement, public and animal health and in severe cases civil-military collaboration. By building a collaborative management culture between these sectors, through joint education, training and exercise activities, better methods and tools will be obtained in order to reach interoperability and an integrated preparedness approach. Lessons learned and experiences from previous projects, courses, workshops, and simulation exercises require a rationale knowledge transfer. Horison scanning is one example of a method that can be recommended to educate strategic analysts jointly from various sectors and the “Decision Theater” is a dynamic and flexible tool that is useful to train decision makers to examine complex bio-agro defense and biosecurity problems.
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| 5. |
- Mårtensson, Per, et al.
(författare)
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Cost and weight efficient partitioning of composite automotive structures
- 2015
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Ingår i: Polymer Composites. - : John Wiley & Sons. - 0272-8397 .- 1548-0569.
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Tidskriftsartikel (refereegranskat)abstract
- To make carbon fiber composites not only weight but also cost effective in high volume production the different cost drivers need to be addressed and new design philosophies considered. This study analyzes integral and differential design approaches when partitioning large complex composite structures. The influence of different partition philosophies are investigated based on a framework of composites manufacturing cost modelling and structural optimization and the effects are exemplified by a case study. The results show that depending on how the partitioning is made the structural performance and the manufacturing cost is affected. More particularly, if the partitioning is made with the most beneficial philosophy differential designs can improve both these important parameters.
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| 6. |
- Mårtensson, Per, et al.
(författare)
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Effects of manufacturing constraints on the cost and weight efficiency of integral and differential automotive composite structures
- 2015
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Ingår i: Composite structures. - : Elsevier. - 0263-8223 .- 1879-1085. ; 134, s. 572-578
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Tidskriftsartikel (refereegranskat)abstract
- The introduction of carbon fibre composites into the high volume automotive sector challenges the design process, since these components not only need to be light but also producible in a cost-efficient manner. One way forward is to introduce manufacturing constraints into the design process, but such constraints affect the freedom of design and opportunities to tailor material properties. This work examines the trade-offs between cost-effective design for manufacturing and the weight optimization of composite structures. This will be achieved by introducing restrictions to the number of plies allowed in structural optimization in order to simplify pre-operations and reduce overall manufacturing investments. Both integral and differential design solutions are considered. It was observed that differential solutions were always more cost and weight efficient than the integral solution, however too severe manufacturing constraints result in an expensive final part due to the additional weight.
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| 7. |
- Mårtensson, Per, et al.
(författare)
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Integral versus differential design for high-volume manufacturing of composite structures
- 2015
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Ingår i: Journal of composite materials. - : Sage Publications. - 0021-9983 .- 1530-793X. ; 49:23, s. 2897-2908
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Tidskriftsartikel (refereegranskat)abstract
- In order to decrease the weight of the automotive body structure and increase the energy efficiency of future cars, attention is now turning towards structural composites, mainly carbon fibre-reinforced plastics. Composites have several advantages such as their excellent weight-specific properties and the possibility to be manufactured in large integral designs for a reduced weight and potentially lower cost. However, carbon fibre composites are expensive and for a cost sensitive industry such as the automotive industry, the challenge lies in creating a favourable business case with a well-balanced trade-off between weight and cost. A method is proposed to visualise the cost and weight advantages of either pursuing an integral design or a differential design, i.e. dividing the structure into a greater number of parts that are later assembled. The method focuses on the impact on cost and weight and considers structures with different part sizes and geometrical complexities. It is shown that, depending on the manufacturing process and series volume, larger and more complex parts may become more cost effective when divided into several, later-joined sub-parts. However, for smaller and/or less complex shapes, an integral design solution is always the best choice.
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| 8. |
- Mårtensson, Per, et al.
(författare)
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Method for cost and weight-efficient material diversity and partitioning of a carbon fibre composite body structure
- 2015
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Ingår i: Proceedings of the Institution of mechanical engineers. Part D, journal of automobile engineering. - : Sage Publications. - 0954-4070 .- 2041-2991.
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Tidskriftsartikel (refereegranskat)abstract
- A method for the early concept phase is proposed, which is aimed at limiting the financial and performance-related riskswhen designing a carbon fibre composite automotive body structure. The method manages the structural requirementsimposed on the complete body structure and analyses the suitability of different carbon fibre material systems and pro-cesses. It also studies whether a high level of material diversity is desirable and the way in which to identify the optimalpartition of the body structure from a material system and manufacturing process selection point of view. Furthermore,since composite materials include both laminated materials and quasi-isotropic materials, an approach is presented thatenables the comparison of these materials variants during conceptual material selection. A case study exemplifies themethod and the results show that, in spite of the cost-sensitive nature of the automotive industry, utilization of the max-imum performance of these expensive composite materials is more important than efforts to achieve a rapid manufac-turing process.
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| 9. |
- Mårtensson, Per, 1976-, et al.
(författare)
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The effects of cost and weight efficient structural design for manufacturing of composite automotive body structures
- 2015
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Ingår i: 20th International Conference on Composite Materials Copenhagen, 19-24th July 2015.
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Konferensbidrag (refereegranskat)abstract
- The automotive industry stands in front of a technology shift in order to adapt to future legislations on more energy efficient cars. Carbon fibre composites are by many seen as the only solution to succeed with this quest. Composite design and manufacturing methodologies need to be developed in order to reach a cost and weight effective design for high annual volumes. Potential advantages with composite materials, such as enabling manufacturing of highly integrated structures with complex geometries, i.e. integral designs, must be explored and questioned. In high series volumes, differential designs, i.e. structures divided with the intention of reducing the part complexity, seems to become more competitive.In this work the effect on financial and structural performance of differential and integral design solutions are addressed. Constraints on laminate and ply thickness as well as minimum ply cut area are considered and their impact on the weight optimisation evaluated. An automotive body structure section is studied and the weight and manufacturing cost is evaluated for both integral and differential design solutions. A cost model addressing both manufacturing and assembly processes are used together with finite element optimisation for the analysis. The results show that the weight efficiency for all design solutions is greatly reduced if the partitioning is made with of a clear focus. The results emphasise the importance of an efficient partitioning philosophy if the advantages of differential design are to be experienced to its fullest and to be able to create a manufacturing optimised design offering both cost and weight efficiency.
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| 10. |
- Mårtensson, Per, 1976-
(författare)
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Cost and weight effective composite design of automotive body structures
- 2014
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The automotive industry stands in front of a great challenge, to decrease its impact on the environment. One important part in succeeding with this is to decrease the structural weight of the body structure and by that the fuel consumption or the required battery power. Carbon fibre composites are by many seen as the only real option when traditional engineering materials are running out of potential for further weight reduction. However, the automotive industry lacks experience working with structural composites and the methods for high volume composite manufacturing are immature. The development of a composite automotive body structure, therefore, needs methods to support and guide the conceptual work to improve the financial and technical results.In this thesis a framework is presented which will provide guidelines for the conceptual phase of the development of an automotive body structure. The framework follows two main paths, one to strive for the ideal material diversity, which also defines an initial partition of the body structure based on the process and material selection. Secondly, a further analysis of the structures are made to evaluate if a more cost and weight efficient solution can be found by a more differential design and by that define the ideal part size.In the case and parameter studies performed, different carbon fibre composite material systems and processes are compared and evaluated. The results show that high performance material system with continuous fibres becomes bothmore cost and performance effective compared to industrialised discontinuous fibre composites. But also that cycle times, sometimes, are less important than a competitive feedstock cost for a manufacturing process. When furtheranalysing the manufacturing design of the structures it is seen that further partition(s) can become cost effective if the size and complexity is large enough.
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