| 1. |
- Johansson, Staffan, et al.
(författare)
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A Novel Approach to Reduction of Frictional Losses in a Heavy-Duty Diesel Engine by Reducing the Hydrodynamic Frictional Losses
- 2017
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Ingår i: Advances in Tribology. - New York : Hindawi Publishing Corporation. - 1687-5915 .- 1687-5923. ; 2017, s. 1-17
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Tidskriftsartikel (refereegranskat)abstract
- An important parameter in the reduction of fuel consumption of heavy-duty diesel engines is the Power Cylinder Unit (PCU); the PCU is the single largest contributor to engine frictional losses. Much attention, from both academia and industry, has been paid to reducing the frictional losses of the PCU in the boundary and mixed lubrication regime. However, previous studies have shown that a large portion of frictional losses in the PCU occur in the hydrodynamic lubrication regime. A novel texturing design with large types of surface features was experimentally analyzed using a tribometer setup. The experimental result shows a significant reduction of friction loss for the textured surfaces. Additionally, the textured surface did not exhibit wear. On the contrary, it was shown that the textured surfaces exhibited a smaller amount of abrasive scratches on the plateaus (compared to the reference plateau honed surface) due to entrapment of wear particles within the textures. The decrease in hydrodynamic friction for the textured surfaces relates to the relative increase of oil film thickness within the textures. A tentative example is given which describes a method of decreasing hydrodynamic frictional losses in the full-scale application. © 2017 Staffan Johansson et al.
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| 2. |
- Anderberg, Cecilia, et al.
(författare)
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Low friction and emission cylinder liner surfaces and the influence of surface topography and scale
- 2019
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Ingår i: Tribology International. - Kidlington : Pergamon Press. - 0301-679X .- 1879-2464. ; 133, s. 224-229
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Tidskriftsartikel (refereegranskat)abstract
- A low friction piston ring pack, with tangential load halved, was tested in engines with four different cylinder liner finishes. Oil consumption, oil temperature and liner surface temperature were monitored at different load and speed levels, under similar test conditions. The two smoother surfaces generally kept lower oil consumption compared to the two rougher ones. Results were correlated using an area-fractal analysis. The relative area of the surface was calculated at different scales and the result was compared with the level of oil consumption for the different liner surfaces at different engine speeds. It was found that oil consumption was strongly correlated with scale for areas of above 1000 μm2 and below 20 μm2. © 2018
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| 3. |
- Barth, Henrik, 1971-, et al.
(författare)
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The use and abuse of 3D-printing from a business model perspective
- 2016
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Konferensbidrag (refereegranskat)abstract
- The paper analyses changes in user activities and behaviour across different types of actors following the introduction of 3D printers. 3D printing, or additive manufacturing, has been claimed to disrupt manufacturing, allowing firms to move from prototyping to full-scale end-part production and replacement part production in a one-step process. 3D printing has many different uses, for example, the manufacturing of toys, shoes, lamps and fashion accessories, and by implication many different types of users and buyers. There are few empirical studies on the types of uses and users of 3D, hampering our understanding in what ways the 3D printers may change the behaviour of users, and whether 3D printers affect the likelihood and the nature of entrepreneurship or business model innovation. To investigate this, a model was created based on the 3DP literature. The model is applied on a distributor customer database and four interview-based illustrative case studies. The empirical findings show that the use of 3DP a) lowers the knowledge and resource barriers for experimentation and entrepreneurial entry, b) increases product and concept prototyping in product development, c) provides a potential for business model innovation by expanding the boundaries of the firm upstream and downstream, and d) becomes a ticket for entrepreneurial entry. Based on our results, the paper suggests that the potential of 3D printers alter user innovative activities is high but most of the potential is latent.
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| 4. |
- Barth, Henrik, 1971-, et al.
(författare)
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The use and abuse of 3D printing - Towards a mobile business model framework
- 2019
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Ingår i: International Journal of Engineering Research and Applications. - Ghaziabad : International Journal of Engineering Research and Applications. - 2248-9622. ; 9:11, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- The paper aim to clarify changes in user activities and behaviour across different types of actors following the development of 3D printers. It proposes a mobile business model and outlining the features of development for direct digital manufacturing.The exploratory study show that the use of 3D printing a) lowers the knowledge and resource barriers for experimentation and entrepreneurial entry, b) increases product and concept prototyping in product development, c) provides a potential for business model innovation by expanding the boundaries of the firm upstream and downstream, and d) becomes a ticket for entrepreneurial entry
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| 5. |
- Dimkovski, Zlate, 1974-, et al.
(författare)
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Functional parameter screening for predicting durability of rolling sliding contacts with different surface finishes
- 2018
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Ingår i: Surface Topography: Metrology and Properties. - Bristol : Institute of Physics Publishing (IOPP). - 2051-672X. ; 6:2
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Tidskriftsartikel (refereegranskat)abstract
- The reliability and lifetime of machine elements such as gears and rolling bearings depend on their wear and fatigue resistance. In order to screen the wear and surface damage, three finishing processes: (i) brushing, (ii) manganese phosphating and (iii) shot peening were applied on three disc pairs and long-term tested on a twin-disc tribometer. In this paper, the elastic contact of the disc surfaces (measured after only few revolutions) was simulated and a number of functional and roughness parameters were correlated. The functional parameters consisted of subsurface stresses at different depths and a new parameter called 'pressure spikes' factor'. The new parameter is derived from the pressure distribution and takes into account the proximity and magnitude of the pressure spikes. Strong correlations were found among the pressure spikes' factor and surface peak/height parameters. The orthogonal shear stresses and Von Mises stresses at the shallowest depths under the surface have shown the highest correlations but no good correlations were found when the statistics of the whole stress fields was analyzed. The use of the new parameter offers a fast way to screen the durability of the contacting surfaces operating at similar conditions. © 2018 IOP Publishing Ltd.
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| 6. |
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| 7. |
- Eriksson, Lars, et al.
(författare)
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Affective surface engineering- using soft and hard metrology to measure the Sensation and perception in surface properties
- 2018
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Ingår i: Proceedings of NordDesign. - Linköping : The Design Society. - 9789176851852
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Konferensbidrag (refereegranskat)abstract
- New surface treatments, novel material developments, and improved quality control procedures and advanced metrology instrumentation create a possibility to further develop competitiveness by the selection of “optimal” surface features”, to a product. The customers first apprehension of a product and the creation of desire is a very complex, but tempting process to learn more about. The interaction between the added quantitative- and the qualitative direct impressions with the customers known and unknown functional demands, social background, and expectations results in sensation and perception, partly possible to quantify and to great extent impossible to pin-down as numbers. Customer sensation and perception are much about psychological factors. There has been a strong industrial- and academic need and interest for methods and tools to quantify and linking product properties to the human response but a lack of studies of the impact of surfaces. This paper aims to introduce a novel approach to develop and join a human sensoric inspired metrology frame-work with qualitative gradings of apprehended impressions of products with varying surface properties. The aim is to establish the metrology framework to link measurable- and unmeasurable impressions of product surfaces to customer FEELING as exemplified by a set of industrial applications. In conclusions of the study, future research in Soft metrology is proposed to allow understanding and modelling of product perception and sensations in combination with a development of the Kansei Surface Engineering methodology and software tools. © Proceedings of NordDesign: Design in the Era of Digitalization, NordDesign 2018. All rights reserved.
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| 8. |
- Flys, Olena, 1971-, et al.
(författare)
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Applicability of characterization techniques on fine scale surfaces
- 2018
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Ingår i: Surface Topography: Metrology and Properties. - Bristol : Institute of Physics Publishing (IOPP). - 2051-672X. ; 6:3
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Tidskriftsartikel (refereegranskat)abstract
- In this study, several surface topographies typical for dental implants were evaluated by different measurement techniques. The samples were prepared by machine turning, wet chemical etching and electrochemical polishing of titanium discs. The measurement techniques included an atomic force microscope (AFM), coherence scanning interferometer (CSI) and a 3D stereo scanning electron microscope (SEM). The aim was to demonstrate and discuss similarities and differences in the results provided by these techniques when analyzing submicron surface topographies. The estimated surface roughness parameters were not directly comparable since the techniques had different surface spatial wavelength band limits. However, the comparison was made possible by applying a 2D power spectral density (PSD) function. Furthermore, to simplify the comparison, all measurements were characterized using the ISO 25178 standard parameters. Additionally, a Fourier transform was applied to calculate the instrument transfer function in order to investigate the behavior of CSI at different wavelength ranges. The study showed that 3D stereo SEM results agreed well with AFM measurements for the studied surfaces. Analyzed surface parameter values were in general higher when measured by CSI in comparison to both AFM and 3D stereo SEM results. In addition, the PSD analysis showed a higher power spectrum density in the lower frequency range 10-2-10-1 μm-1 for the CSI compared with the other techniques.
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| 9. |
- Flys, Olena, 1971-, et al.
(författare)
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Characterization of surface topography of a newly developed metrological gloss scale
- 2015
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Ingår i: Surface Topography: Metrology and Properties. - Bristol : Institute of Physics (IOP). - 2051-672X. ; 3:4
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Tidskriftsartikel (refereegranskat)abstract
- In the European Joint Research Project 'Multidimensional Reflectometry for Industry', a new gloss scale was developed with the aim to represent different levels of gloss, hue, roughness, and refractive indices. In this paper, the surfaces of six selected samples were thoroughly investigated using various measuring techniques in order to verify the outcome of the novel manufacturing processes in terms of distinct levels as well as types of surface roughness. The aim of the evaluation was to capture surface structures in different wavelength intervals utilizing a confocal microscope, a coherence scanning interferometer, and an atomic force microscope. Power spectral density functions were also calculated from the measurements and used to determine suitability of techniques for different roughness scales. The measurements show that the expected surface characteristics as well as different RMS roughness values are intimately connected to the perceived glossiness.
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| 10. |
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