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Bäckström, Mikael
Alternative names
Publications (10 of 64) Show all publications
Petrone, N., Candiotto, G., Marzella, E., Uriati, F., Carraro, G., Bäckström, M. & Koptioug, A. (2019). Feasibility of using a novel instrumented human head surrogate to measure helmet, head and brain kinematics and intracranial pressure during multidirectional impact tests. Journal of Science and Medicine in Sport
Open this publication in new window or tab >>Feasibility of using a novel instrumented human head surrogate to measure helmet, head and brain kinematics and intracranial pressure during multidirectional impact tests
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2019 (English)In: Journal of Science and Medicine in Sport, ISSN 1440-2440, E-ISSN 1878-1861Article in journal (Refereed) Epub ahead of print
Abstract [en]

Objectives: Aim of the work is to present the feasibility of using an Instrumented Human Head Surrogate (IHHS-1) during multidirectional impacts while wearing a modern ski helmet. The IHHS-1 is intended to provide reliable and repeatable data for the experimental validation of FE models and for the experimental evaluation of modern helmets designed to enhance the degree of protection against multidirectional impacts. Design: The new IHHS-1 includes 9 triaxial MEMS accelerometers embedded in a silicone rubber brain, independently molded and presenting lobes separation and cerebellum, placed into an ABS skull filled with surrogate cerebrospinal fluid. A triaxial MEMS gyroscope is placed at the brain center of mass. Intracranial pressure can be detected by eight pressure sensors applied to the skull internal surface along a transversal plane located at the brain center of mass and two at the apex. Additional MEMS sensors positioned over the skull and the helmet allow comparison between outer and inner structure kinematics and surrogate CSF pressure behavior. Methods: The IHHS-1 was mounted through a Hybrid III neck on a force platform and impacted with a striker connected to a pendulum tower, with the impact energies reaching 24J. Impact locations were aligned with the brain center of mass and located in the back (sagittal axis), right (90° from sagittal axis), back/right (45°), and front right (135°) locations. Following dynamic data were collected: values of the linear accelerations and angular velocities of the brain, skull and helmet; intracranial pressures inside the skull. Results: Despite the relatively low intensity of impacts (HIC at skull max value 46), the skull rotational actions reached BrIC values of 0.33 and angular accelerations of 5216 rad/s2, whereas brain angular acceleration resulted between 1,44 and 2,1 times lower with similar values of BrIC. Conclusions: The IHHS-1 is a physical head surrogate that can produce repeatable data for the interpretation of inner structures behavior during multidirectional impacts with or without helmets of different characteristics. 

Keywords
Accelerometers, Angular velocity, Helmet evaluation, Human head, Intracranial pressure, Surrogate
Identifiers
urn:nbn:se:miun:diva-36704 (URN)10.1016/j.jsams.2019.05.015 (DOI)
Note

Available online 30 May 2019

Available from: 2019-07-10 Created: 2019-07-10 Last updated: 2019-07-10Bibliographically approved
Petrone, N., Carraro, G., Dal Castello, S., Broggio, L., Koptioug, A. & Bäckström, M. (2018). A Novel Instrumented Human Head Surrogate For The Impact Evaluation Of Helmets. In: Dr Hugo Espinosa, David R. Rowlands, Jonathan Shepherd, Professor David Thiel (Ed.), Proceedings, Volume 2, ISEA 2018: . Paper presented at 12th Conference on the Engineering of Sport, Brisbane, Australia, 26 to 29 March 2018 (pp. 269). , 2, Article ID 6.
Open this publication in new window or tab >>A Novel Instrumented Human Head Surrogate For The Impact Evaluation Of Helmets
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2018 (English)In: Proceedings, Volume 2, ISEA 2018 / [ed] Dr Hugo Espinosa, David R. Rowlands, Jonathan Shepherd, Professor David Thiel, 2018, Vol. 2, p. 269-, article id 6Conference paper, Published paper (Refereed)
Abstract [en]

A novel Human Head Surrogate was obtained from available MRI scans of a 50th percentile male human head. Addictive manufacturing was used to produce the skull, the brain and the skin. All original MRI geometries were partially smoothed and adjusted to provide the best biofidelity compatible with printing and molding technology. The skull was 3D-printed in ABS and ten pressure sensors were placed into it. The brain surrogate was cast from silicon rubber in the 3d-printed plastic molds. Nine tri-axial accelerometers (placed at the tops of the lobes, at the sides of the lobes, in the cerebellum and in the center of mass) and a three-axis gyroscope (at the center of mass) were inserted into the silicon brain during casting. The cranium, after assembly with brain, was filled with silicon oil mimicking the cerebral fluid. Silicon rubber was cast in additional 3d-printed molds to form the skin surrounding the cranium. The skull base was adapted to be compatible with the Hybrid-III neck and allow the exit of brain sensors cabling. Preliminary experiments were carried out proving the functionality of the surrogate. Results showed how multiple accelerometers and pressure sensors allowed a better comprehension of the head complex motion during impacts.

Keywords
human head, surrogate, additive manufacturing, accelerometers, impact tests
National Category
Medical Laboratory and Measurements Technologies Other Materials Engineering Other Mechanical Engineering Interaction Technologies
Identifiers
urn:nbn:se:miun:diva-32502 (URN)10.3390/proceedings2060269 (DOI)
Conference
12th Conference on the Engineering of Sport, Brisbane, Australia, 26 to 29 March 2018
Projects
STII
Funder
VINNOVA
Available from: 2017-12-19 Created: 2017-12-19 Last updated: 2018-04-25Bibliographically approved
Koptioug, A., Bäckström, M., Botero Vega, C. A., Popov, V. & Chudinova, E. (2018). Developing new materials for Electron Beam Melting: experiences and challenges. In: : . Paper presented at THERMEC'2018 International Conference on Processing and Manufacturing of Advanced Materials Processing, Fabrication, Properties, Applications, Paris, France July 8-13, 2018 (pp. 2190-2195). , 941
Open this publication in new window or tab >>Developing new materials for Electron Beam Melting: experiences and challenges
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2018 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Lack of industrially available materials for additive manufacturing (AM) of metallic materials along with the promises of materials with improved or unique properties provides a strong drive for developing new process/material combinations. As powder bed technologies for metallic materials are relatively new to the market, and to some extent are only maturing, developers of new process/material combinations have certain challenges to overcome. Firstly, basic knowledge on the behavior of materials (even those well established for other applications) under extreme conditions of melting/solidification with beam-based AM methods is far from being adequate. Secondly, manufacturing of the equipment is up to date driven by industrial application, thus optimization of the AM machines for small test batches of powders is still belongs to research and development projects. Also, majority of the powder manufacturers are primarily driven by the market development, and even they are well aware of the demands imposed by the powder bed AM machines, availability of small test batches of adequate powders may be problematic or at least quite costly for the R&D oriented users. Present paper describes the experiences in developing new materials for EBM A2 machine by Arcam EBM, modified for operating with powder batches of 100-200 ml and less. In particular it discusses achievements and challenges of working with powders from different materials with specifications far beyond the range suggested by machine manufacturer. Also it discusses the possibility of using blended rather than pre-alloyed powders for achieving both composite-like and alloyed materials in the same part by steering electron beam energy deposition strategy.

Keywords
Additive Manufacturing, Electron Beam Melting, material development, blended powders, in situ alloying, composite materials
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:miun:diva-35136 (URN)10.4028/www.scientific.net/MSF.941.2190 (DOI)000468152500361 ()
Conference
THERMEC'2018 International Conference on Processing and Manufacturing of Advanced Materials Processing, Fabrication, Properties, Applications, Paris, France July 8-13, 2018
Note

Paper accepted, in print

Available from: 2018-12-10 Created: 2018-12-10 Last updated: 2019-07-08Bibliographically approved
Botero Vega, C. A., Jiménez-Piqué, E., Roos, S., Skoglund, P., Koptioug, A., Rännar, L.-E. & Bäckström, M. (2018). Nanoindentation: a suitable tool in metal Additive Manufacturing. In: : . Paper presented at Materials Science & Technology, MS&T 2018, October 14-18, Columbus, USA.
Open this publication in new window or tab >>Nanoindentation: a suitable tool in metal Additive Manufacturing
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2018 (English)Conference paper, Oral presentation only (Refereed)
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:miun:diva-35342 (URN)
Conference
Materials Science & Technology, MS&T 2018, October 14-18, Columbus, USA
Available from: 2018-12-21 Created: 2018-12-21 Last updated: 2019-01-09Bibliographically approved
Skoglund, P., Botero Vega, C. A., Koptioug, A., Rännar, L.-E. & Bäckström, M. (2018). Possibility of the “cold start” of the build in Electron Beam Melting. In: : . Paper presented at Materials Science & Technology, MS&T 2018, October 14-18, Columbus, USA.
Open this publication in new window or tab >>Possibility of the “cold start” of the build in Electron Beam Melting
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2018 (English)Conference paper, Oral presentation only (Refereed)
National Category
Other Mechanical Engineering
Identifiers
urn:nbn:se:miun:diva-35345 (URN)
Conference
Materials Science & Technology, MS&T 2018, October 14-18, Columbus, USA
Available from: 2018-12-21 Created: 2018-12-21 Last updated: 2019-01-09Bibliographically approved
Petrone, N., Giacomin, M., Koptioug, A. & Bäckström, M. (2018). Racing Wheels’ Effect on Drag/Side Forces Acting on a Cyclist at Sportstech-Miun Wind Tunnel. In: Dr Hugo Espinosa, David R. Rowlands, Jonathan Shepherd, Professor David Thiel (Ed.), Proceedings, Volume 2, ISEA 2018: . Paper presented at 12th Conference on the Engineering of Sport, Brisbane, Australia, 26-28 March 2018 (pp. 210). , 2, Article ID 6.
Open this publication in new window or tab >>Racing Wheels’ Effect on Drag/Side Forces Acting on a Cyclist at Sportstech-Miun Wind Tunnel
2018 (English)In: Proceedings, Volume 2, ISEA 2018 / [ed] Dr Hugo Espinosa, David R. Rowlands, Jonathan Shepherd, Professor David Thiel, 2018, Vol. 2, p. 210-, article id 6Conference paper, Published paper (Refereed)
Abstract [en]

Abstract: the wind tunnel at the SportsTech Research Centre at Mid Sweden University (MIUN, Östersund) was opened in 2015 for sports technology research. It is dedicated primarily to analysis of equipment performance and garment development and especially suitable for roller skiing, running and cycling. The aim of this work was to develop a full-scale study to investigate the aerodynamic behaviour of a cyclist facing front and cross wind at different yaw angles (from 0° to 30°) and speeds. To reach this goal, a rotating structure supported by a force platform was constructed. It includes a set of rollers on which fully unrestrained cycling is possible. The method was applied to the comparison of three wheelsets (differing in material, height and shape of the rim, number and shape of spokes) in terms of drag and side aerodynamic forces during a cyclist’s ride at 30 km/h, while keeping all the other factors constant. Resulting curves allowed estimating differences of 4% and 9% when applied to a recent time trial competition.

Keywords
aerodynamics, cycling, wheels, wind tunnel, drag, side, full-scale
National Category
Fluid Mechanics and Acoustics Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Identifiers
urn:nbn:se:miun:diva-32501 (URN)10.3390/proceedings2060210 (DOI)
Conference
12th Conference on the Engineering of Sport, Brisbane, Australia, 26-28 March 2018
Projects
STII
Funder
VINNOVA
Available from: 2017-12-19 Created: 2017-12-19 Last updated: 2018-04-25Bibliographically approved
Koptioug, A., Bäckström, M., Ainegren, M. & Nilsson, K. (2018). Studying Moisture Transport Trough "Active" Fabrics Using Humidity-Temperature Sensor Nodes. In: Dr Hugo Espinosa, David R. Rowlands, Jonathan Shepherd, Professor David Thiel (Ed.), Proceedings, Volume 2, ISEA 2018: . Paper presented at 12th Conference on the Engineering of Sport, Brisbane, Australia, 26-28 March 2018 (pp. 230). , 2, Article ID 6.
Open this publication in new window or tab >>Studying Moisture Transport Trough "Active" Fabrics Using Humidity-Temperature Sensor Nodes
2018 (English)In: Proceedings, Volume 2, ISEA 2018: / [ed] Dr Hugo Espinosa, David R. Rowlands, Jonathan Shepherd, Professor David Thiel, 2018, Vol. 2, p. 230-, article id 6Conference paper, Published paper (Refereed)
Abstract [en]

Active fabrics providing better comfort of the garments and footwear rapidly become an essential part of our life. However, only limited information about the performance of such fabrics is commonly available for the garment and footwear designers, and tests are often done only with the final products. Thus development of the objective testing methods for the fabric assemblies containing microporous membranes and garments using them is one of the important topics. Garment tests in the climate chamber when exercising in windy and rainy conditions with a set of temperature and humidity sensors placed over the body allow comparing manufactured garments for thermal and humidity comfort. To allow for better material testing a new laboratory setup was developed for studying the dynamics of the humidity transport through different fabrics at realistic conditions in extension of the existing ISO test procedure. Present paper discusses the experimental procedures and first results acquired with new setup.

Keywords
active fabrics, garments comfort, microporous membranes, humidity transport, experimental setup
National Category
Textile, Rubber and Polymeric Materials
Identifiers
urn:nbn:se:miun:diva-32499 (URN)10.3390/proceedings2060230 (DOI)
Conference
12th Conference on the Engineering of Sport, Brisbane, Australia, 26-28 March 2018
Projects
STII
Funder
VINNOVA
Available from: 2017-12-19 Created: 2017-12-19 Last updated: 2018-04-25Bibliographically approved
Koptioug, A., Rännar, L.-E., Botero Vega, C. A., Bäckström, M. & Popov, V. (2018). Unique material compositions obtained by Electron beam melting of blended powders. In: Euro PM2018 Proceedings: . Paper presented at Euro PM2018 Congress & Exhibition, Bilbao, Spain, 14-18 October, 2018. European Powder Metallurgy Association, EPMA
Open this publication in new window or tab >>Unique material compositions obtained by Electron beam melting of blended powders
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2018 (English)In: Euro PM2018 Proceedings, European Powder Metallurgy Association, EPMA , 2018Conference paper, Published paper (Refereed)
Abstract [en]

Today powder bed fusion based (PBF) additive manufacturing (AM) methods in metallic materials mainly employ pre-alloyed precursor powders. It was even somehow assumed that in situ alloying of the blended powders will not be effective and such PBF processing will not yield any valuable materials. Recent studies carried out both for laser- and electron beam- based PBF have demonstrated possibilities of using precursors blended from both elemental and alloyed powders. We also demonstrate that composites and alloys indeed can be manufactured from a range of different pre-blended powders with Electron Beam Melting (EBM). It is also possible achieving both composites and alloys by design in different parts of the manufactured components by varying the beam energy deposition strategy. Using sequentially fed precursor powders together with a new powder delivery system also allows manufacturing of the functionally graded materials with gradual composition variation. Blended powder precursors and sequential powder feeding should provide opportunities of manufacturing components with changing composition and material properties in a single manufacturing process. It makes possible modern industrial manufacturing of materials similar to Damascus steels, and other composites and composite-like materials in combinations with alloyed and gradient sections by choice in different parts of components.  

Place, publisher, year, edition, pages
European Powder Metallurgy Association, EPMA, 2018
Keywords
powder bed, additive manufacturing, electron beam melting, new materials, powder belnds, composite materials
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:miun:diva-35137 (URN)978-1-899072-50-7 (ISBN)
Conference
Euro PM2018 Congress & Exhibition, Bilbao, Spain, 14-18 October, 2018
Available from: 2018-12-10 Created: 2018-12-10 Last updated: 2018-12-11Bibliographically approved
Koptioug, A., Bäckström, M. & Rännar, L.-E. (2017). 3D-printing: a future “magic wand” for global manufacturing. How can we benefit from it today for sports and health care?. In: Jan Cabri, Pedro Pezarat Correia (Ed.), Proceedings of the 5th International Congress on Sport Sciences Research and Technology Support, icSPORTS: . Paper presented at 5th International Congress on Sport Sciences Research and Technology Support, icSPORTS, Portugal, 30-31 October 2017. INSTICC Press
Open this publication in new window or tab >>3D-printing: a future “magic wand” for global manufacturing. How can we benefit from it today for sports and health care?
2017 (English)In: Proceedings of the 5th International Congress on Sport Sciences Research and Technology Support, icSPORTS / [ed] Jan Cabri, Pedro Pezarat Correia, INSTICC Press, 2017Conference paper, Published paper (Refereed)
Abstract [en]

3D-printing, or as it is also known, additive manufacturing (AM), is promising to be one of the determining manufacturing technologies of the present century. It is not a single technology but a family of rather different ones common in the way components are made, adding materials layer by layer. Additive manufacturing is already quite competitive to existing and well established technologies, but it also can provide unprecedented flexibility and complexity of shapes making components from the materials as different as cheese, chocolate and cream, live cells, concrete, polymers and metal. Many more materials we were not even thinking about few years ago are also becoming available in additive manufacturing, making it really believable that “only the sky is the limit”. During the time available for the keynote lecture, we will analyze the present position of AM in relation to other technologies, the features that make it so promising and its influence upon the part of our life we call sports and health, using the examples relevant to the Congress areas from computer systems to sports performance. Out of all enormities of materials available for different representatives of this manufacturing family we will concentrate at polymers and metals. AM technologies working with these two material families are already providing some unique solutions within the application areas relevant to the Congress' scope. We will also talk about some limitations inherent to the AM in polymers and metals to have the awareness that though the limit is somewhere “high in the sky”, it still exists.

Place, publisher, year, edition, pages
INSTICC Press, 2017
Keywords
Additive Manufacturing, Sports Technology, Active Lifestyle, Research and Development, Education
National Category
Other Engineering and Technologies not elsewhere specified Manufacturing, Surface and Joining Technology Other Materials Engineering
Identifiers
urn:nbn:se:miun:diva-32506 (URN)2-s2.0-85055289834 (Scopus ID)978-98-97-58269-1 (ISBN)
Conference
5th International Congress on Sport Sciences Research and Technology Support, icSPORTS, Portugal, 30-31 October 2017
Projects
STII
Funder
VINNOVA
Available from: 2017-12-19 Created: 2017-12-19 Last updated: 2018-12-07Bibliographically approved
Klingvall Ek, R., Bäckström, M. & Rännar, L.-E. (2017). Fatigue properties of Ti-6Al-4V manufactured using electron beam melting. In: Proceedings Euro PM 2017: International Powder Metallurgy Congress and Exhibition 2017: . Paper presented at International Powder Metallurgy Congress and Exhibition, Euro PM 2017; Milano Congressi (MiCo)Milan; Italy; 1 October 2017 through 4 October 2017. Brussels: EPMA European Powder Metallurgy Association
Open this publication in new window or tab >>Fatigue properties of Ti-6Al-4V manufactured using electron beam melting
2017 (English)In: Proceedings Euro PM 2017: International Powder Metallurgy Congress and Exhibition 2017, Brussels: EPMA European Powder Metallurgy Association , 2017Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

The interest in powder bed fusion additive manufacturing methods, such as electron beam melting (EBM), is increasing constantly and main business areas driving the development are aerospace and implant manufacturers. EBM manufactured parts have a rather coarse surface roughness mainly originating from the layer thickness and the powder grains melted by the electron beam. Thus, there is an interest in understanding how the surface properties influences the fatigue performance of the material. In this study, EBM manufactured Ti-6Al-4V was investigated at high cycle fatigue using rotating beam and different types of specimens regarding geometry, as-built and hot isostatic pressing (HIP) post-processing were evaluated. The results confirm that as-built surfaces affect the fatigue limit and a small size specimen geometry for rotating beam fatigue testing is proposed as a part of material and process verification.

Place, publisher, year, edition, pages
Brussels: EPMA European Powder Metallurgy Association, 2017
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:miun:diva-32484 (URN)2-s2.0-85056550071 (Scopus ID)978-1-899072-49-1 (ISBN)
Conference
International Powder Metallurgy Congress and Exhibition, Euro PM 2017; Milano Congressi (MiCo)Milan; Italy; 1 October 2017 through 4 October 2017
Available from: 2017-12-18 Created: 2017-12-18 Last updated: 2018-12-14Bibliographically approved
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