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Häggström, D., Sellgren, U. & Björklund, S. (2022). Thermomechanical performance of carbon fiber reinforced polymer synchronizer friction liners. Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, 236(6), 1074-1080
Open this publication in new window or tab >>Thermomechanical performance of carbon fiber reinforced polymer synchronizer friction liners
2022 (English)In: Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, ISSN 1350-6501, E-ISSN 2041-305X, Vol. 236, no 6, p. 1074-1080Article in journal (Refereed) Published
Abstract [en]

To improve the ability of a thermomechanical simulation model for carbon fiber reinforced polymer lined synchronizers to predict synchronization performance and reliability, temperature dependent material data for the specific carbon fiber reinforced polymer lining is needed. The compressive modulus, coefficient of thermal expansion, specific heat and thermal conductivity are determined experimentally. The effect of each material property on the focal surface temperature is analyzed, and it is shown that the compressive modulus has the largest influence for all analyzed load cases. Physical tests show that surface hot spots begin to appear at a simulated focal surface temperature of 200 (Formula presented.) C, while performance degradation occurs at a simulated focal surface temperature of 230 (Formula presented.) C–250 (Formula presented.) C. 

Place, publisher, year, edition, pages
SAGE Publications, 2022
Keywords
Atmospheric temperature, Carbon fiber reinforced plastics, Reinforcement, Specific heat, Synchronization, Thermal conductivity, Thermal expansion, Carbon fibre reinforced polymer, Compressive moduli, Focal surfaces, Performance and reliabilities, Simulation model, Surface temperatures, Synchronization performance, Temperature-dependent material, Thermo-mechanical performance, Thermomechanical simulation, Surface properties
National Category
Other Materials Engineering Materials Chemistry
Identifiers
urn:nbn:se:kth:diva-313609 (URN)10.1177/13506501211053415 (DOI)000727015900001 ()2-s2.0-85120615159 (Scopus ID)
Note

QC 20220610

Available from: 2022-06-10 Created: 2022-06-10 Last updated: 2022-06-25Bibliographically approved
Saghari, A., Kosari, A., Sellgren, U. & Ebrahimi, M. (2021). Utilizing the uncertainty-based MADM-optimization approach to find robust-reliable design parameters for a platform-based product by considering aleatory uncertainties and human judgment effect. Research in Engineering Design, 32(1), 105-126
Open this publication in new window or tab >>Utilizing the uncertainty-based MADM-optimization approach to find robust-reliable design parameters for a platform-based product by considering aleatory uncertainties and human judgment effect
2021 (English)In: Research in Engineering Design, ISSN 0934-9839, E-ISSN 1435-6066, Vol. 32, no 1, p. 105-126Article in journal (Refereed) Published
Abstract [en]

In this paper, a new methodology was proposed for finding optimal robust-reliable parameter values of a space-based earth observation (SEO) mission based on a predefined multi-purpose platform considering influential uncertainties and human judgment. A deterministic optimization was performed using an evolutionary algorithm on the basis of platform capability and mission-required performance, simulated by a dynamic simulation-based model. A set of non-dominated solutions with different behaviors emerged. Then, samples of these solutions were selected and an uncertainty analysis was carried out. After that, a multiple attribute decision-making (MADM) problem was formed with two groups of attributes related to constraints҆ violations and variation of objective function value having unknown weights. Dominant ranking of the non-dominated solutions was obtained by simulating this MADM problem for adequate times with different random weights (human judgment effects). In the next step, given the outputs obtained from solving MADM problem, an optimal robust-reliable solution could be determined utilizing two approaches, response surface methodology (RSM) and forming a new uncertainty-based multidisciplinary design optimization (UMDO) problem. The results showed that utilizing MADM approach not only brings the effects of human judgment into design problem but also accelerates convergence to optimal robust-reliable solution in multimodal problems by bounding the search space without any risk regarding getting stuck in local optimal regions.

Place, publisher, year, edition, pages
Springer Nature, 2021
Keywords
Decision making under uncertainty, Dynamic simulation-based model, Multiple attribute decision making, Optimization under uncertainty, Platform-based product family design, Response surface methodology, Robust-reliable design, Space-based EO mission
National Category
Computational Mathematics
Identifiers
urn:nbn:se:kth:diva-291713 (URN)10.1007/s00163-020-00349-2 (DOI)000583635500001 ()2-s2.0-85094657935 (Scopus ID)
Note

QC 20210318

Available from: 2021-03-18 Created: 2021-03-18 Last updated: 2022-06-25Bibliographically approved
Williamsson, D. & Sellgren, U. (2020). Architecting a Modular Battery Electric Truck. In: ASME 2020 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference.: . Paper presented at ASME 2020 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Virtual, Online, 17-19 August 2020. ASME International, 9, Article ID DETC2020-22009.
Open this publication in new window or tab >>Architecting a Modular Battery Electric Truck
2020 (English)In: ASME 2020 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference., ASME International , 2020, Vol. 9, article id DETC2020-22009Conference paper, Published paper (Refereed)
Abstract [en]

Product architecting involves conceptual system design, module identification (clustering) and product layout design. In this paper, we propose a new extended version of the previously introduced Integrated Modularization Methodology (IMM) that integrates technical complexity and business strategic concerns into product architecture clustering. The extended IMM (eIMM) adds physical interference and implementation dependent behavior into architecture clustering. The proposed method is logically verified by an industrial case, where the architecture of a presently developed battery electric truck is used as a test bench for studying if and how the product architecture DSM and eIMM approaches may enable us to identify module candidates that are reasonable trade-offs between technical complexity, business strategies and physical interferences. The case study indicates that the eIMM is able to propose a modular product architecture with reasonable module candidates from a technical complexity point of view, and without conflicting business strategies or intra-modular physical interferences.

Place, publisher, year, edition, pages
ASME International, 2020
Keywords
Product Architecting, Business Strategy, MFD, Clustering, Complexity, DSM, Integrated Modularization
National Category
Other Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-286345 (URN)10.1115/DETC2020-22009 (DOI)2-s2.0-85096134807 (Scopus ID)
Conference
ASME 2020 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Virtual, Online, 17-19 August 2020
Note

QC 20210114

Available from: 2020-11-25 Created: 2020-11-25 Last updated: 2023-12-05Bibliographically approved
Sellgren, U. & Williamsson, D. (2020). Architecting Complex Engineered Systems. In: Proceedings of the Design Society: DESIGN Conference. Paper presented at 16th International Design Conference, DESIGN 2020, 26 October 2020 through 29 October 2020 (pp. 2415-2424). Cambridge University Press (CUP)
Open this publication in new window or tab >>Architecting Complex Engineered Systems
2020 (English)In: Proceedings of the Design Society: DESIGN Conference, Cambridge University Press (CUP) , 2020, p. 2415-2424Conference paper, Published paper (Refereed)
Abstract [en]

Novel products are commonly realized by integrating heterogeneous technologies. Product architecting focus on defining the scheme by which the product functions are allocated to physical components. A DSM-based clustering method that integrates technical complexity and strategic concerns has previously been proposed. It has been shown that interaction weights in the DSM may affect the clustering result. A complexity-based interaction strength model to be used in DSM clustering is proposed here. The case study gives promising results from both interaction performance and safety points of view.

Place, publisher, year, edition, pages
Cambridge University Press (CUP), 2020
Keywords
complex systems, design structure matrix (DSM), systems engineering (SE), Clustering algorithms, Clustering results, Complex engineered systems, Complexity based, Heterogeneous technology, Interaction strength, Physical components, Product functions, Technical complexity, Design
National Category
Other Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-300997 (URN)10.1017/dsd.2020.335 (DOI)2-s2.0-85110271850 (Scopus ID)
Conference
16th International Design Conference, DESIGN 2020, 26 October 2020 through 29 October 2020
Note

QC 20210906

Available from: 2021-09-06 Created: 2021-09-06 Last updated: 2022-06-25Bibliographically approved
Williamsson, D. & Sellgren, U. (2020). Choosing proper relation weights in product architecture clustering: a literature review.
Open this publication in new window or tab >>Choosing proper relation weights in product architecture clustering: a literature review
2020 (English)Report (Other academic)
Abstract [en]

This technical report was conducted at the department YMS - PDM & CAD (Product Data Management & Computer Aided Design) at Scania and at KTH Royal Institute of Technology in Stockholm, Sweden. The report serves as a part delivery of a PhD project, within the area of modularization and product description, performed by the author.Scania is one of the leading truck, bus and engine manufacturers in the world and is today a part of TRATON SE (owned by Volkswagen AG), which is one of the world’s largest vehicle manufacturing groups. Scania has a successful history in vehicle modularization and claims it is one of the most important reasons why they are a leading company today. However, the Scania product has over the last years been developed into a Cyber-Physical System (CPS), with embedded software in focus, demanding the modularization methodology to support this new dimension. There is also a growing market regarding offline and online services, which also generates new demands.Earlier published research within the presented PhD project identified that a structured methodology which supports the development of the product architecture was needed at Scania, mainly to manage the increasing technical complexity in the Cyber-Physical Systems. Hence, a new clustering based method for product modularization that integrates product complexity and company business strategies was proposed by the author. The new method was named Integrated Modularization Methodology (IMM) due to the integrated approach for identifying module candidates during the clustering stage.One of the main challenges when using any clustering based modularization approach is to determine proper relation weights (importance), including the reasons behind the weights, and how the weights affects the clustering results. Hence, the main purpose of this technical report was to systematically investigate possible aspects which may affect the product architecture and thereby the relation weights, i.e. the reasons to consider when choosing proper relation weights in the architecture clustering analysis.The results from the report indicate that the importance of the design requirements needs to be reflected in the chosen relation weights, given that the DSM-clustering result is sensitive to the relative relation weights.

Publisher
p. 23
Series
TRITA-ITM-RP ; 5020:2
Keywords
Modularization, Product architecture, DSM-clustering, relation weights
National Category
Other Mechanical Engineering
Research subject
Machine Design
Identifiers
urn:nbn:se:kth:diva-266984 (URN)978-91-7873-452-8 (ISBN)
Note

QC 20200128

Available from: 2020-01-29 Created: 2020-01-29 Last updated: 2022-09-09Bibliographically approved
Häggström, D., Sellgren, U. & Björklund, S. (2020). Optimization of synchronizer cone angle with regard to manufacturing tolerances of cone roundness and cone angle. Proceedings of the Institution of mechanical engineers. Part D, journal of automobile engineering, 234(2-3), 681-688
Open this publication in new window or tab >>Optimization of synchronizer cone angle with regard to manufacturing tolerances of cone roundness and cone angle
2020 (English)In: Proceedings of the Institution of mechanical engineers. Part D, journal of automobile engineering, ISSN 0954-4070, E-ISSN 2041-2991, Vol. 234, no 2-3, p. 681-688Article in journal (Refereed) Published
Abstract [en]

The effects of manufacturing tolerances on the maximum focal temperature has been investigated by transient thermomechanical simulations. Both relative cone angle and cone out-of-roundness for molybdenum and carbon fibre reinforced polymer synchronizers were evaluated. It was shown that cone out-of-roundness significantly increases the focal contact temperature for that specific cone but has little impact on the opposing cone. Two populations of measured synchronizers were evaluated, and it was shown that the maximum focal surface temperature can be decreased in almost all tolerance cases by introducing a relative angle between the cones.

Place, publisher, year, edition, pages
SAGE PUBLICATIONS LTD, 2020
Keywords
Commercial vehicles, heavy duty vehicles, transmission, vehicle reliability, durability, automotive components, synchronizer, tolerances
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-269018 (URN)10.1177/0954407019854594 (DOI)000511536700026 ()2-s2.0-85067845158 (Scopus ID)
Note

QC 20200319

Available from: 2020-03-19 Created: 2020-03-19 Last updated: 2022-09-09Bibliographically approved
Andersson, K., Hagnestål, A. & Sellgren, U. (2019). A Flexible Chain Proposal for Winch-Based Point Absorbers. Journal of mechanical design (1990), 141(10), Article ID 102301.
Open this publication in new window or tab >>A Flexible Chain Proposal for Winch-Based Point Absorbers
2019 (English)In: Journal of mechanical design (1990), ISSN 1050-0472, E-ISSN 1528-9001, Vol. 141, no 10, article id 102301Article in journal (Refereed) Published
Abstract [en]

Ocean wave power is a promising renewable energy source. It has, however, been difficult to find a cost-effective solution to convert wave energy into electricity. The harsh marine environment and the fact that wave power is delivered with large forces at low speed make design of durable mechanical structures and efficient energy conversion challenging. The dimensioning forces strongly depend on the wave power concept, the wave energy converter (WEC) implementation, and the actual power take-off (PTO) system. A WEC with a winch as a power take-off system, i.e., a winch-based point absorber (WBPA), could potentially enable a low levelized cost of energy (LCOE) if a low-cost, durable and efficient winch that can deal with peak loads can be developed. A key challenge for realizing such a winch is to find a force transmitting solution that can deal with these peak loads and that can handle up to 80 million cycles during its life. In this article, we propose a design solution for a force transmitting chain with elastomer bearings connecting the links of the chain. With this solution no sliding is present, and the angular motion is realized as elastic shear deformations in the elastomer bearings when the chain is wound onto the winch drum. The elastomer bearings were designed for low shear stiffness and high compression stiffness, and the links were designed primarily to minimize the number of joints in the chain. Thereby, the maximum allowed relative angle between the links when rolled up over the drum should be as large as possible within practical limits. Finite element-based topological optimization was performed with the aim to increase the link strength to weight ratio. A test rig for a first proof of concept testing has been developed, and preliminary test results indicate that this chain concept with elastomer bearings can be a potential solution for a durable chain and should be analyzed and tested further for fatigue and sea operations.

Place, publisher, year, edition, pages
ASME, 2019
Keywords
chain transmission, elastomer bearing, power take-off system, wave power
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-267193 (URN)10.1115/1.4043315 (DOI)000506890700012 ()2-s2.0-85065758383 (Scopus ID)
Note

QC 20200204

Available from: 2020-02-04 Created: 2020-02-04 Last updated: 2022-09-09Bibliographically approved
Bergseth, E., Henriksson, M., Dizdar, S. & Sellgren, U. (2019). Effects of thrust washer bearing surface characteristics on planetary gear train wear. Wear, 432-433, Article ID 202933.
Open this publication in new window or tab >>Effects of thrust washer bearing surface characteristics on planetary gear train wear
2019 (English)In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 432-433, article id 202933Article in journal (Refereed) Published
Abstract [en]

Thrust washers in spur planetary gears are placed between the planet wheel and planet carrier and act as spacers and wear pads. Metal to metal sliding contact between the planet wheel – washer – carrier causes frictional power losses that, combined with starved lubrication, may cause high contact temperatures and thermo-mechanical effects that potentially trigger thermo-elastic instabilities and excessive local wear. The planetary gear system would benefit from a low-friction interface between the washer and the planet wheel. Five washers with different surface treatments were tested in a full-scale gear rig. These tests were also replicated as closely as possible in a pin-on-disc tribometer. The following types of finishing material treatments were studied: a chemical nickel coating plus polymer on a nitro-carburised surface, a combination of nitro-carburization and solid lubricant layers, electroless deposited chemical nickel coating plus polymer, nitro-carburizing, and manganese phosphating. The frictional results indicate that tribometer tests can be used to compare and classify new washer materials. Lab scale tests show that a new experimental self-lubricating tribomaterial that was applied with laser cladding has a promising potential to increase planetary gear train robustness and service life, especially if the surface is fine grinded.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Thrust washers, Planetary gears, Adhesive wear, Surface treatment, Laser cladding
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Transport Science; Machine Design
Identifiers
urn:nbn:se:kth:diva-258028 (URN)10.1016/j.wear.2019.202933 (DOI)000477874700023 ()2-s2.0-85067419223 (Scopus ID)
Funder
Swedish Foundation for Strategic Research , SM15-0025
Note

QC 20191007

Available from: 2019-09-09 Created: 2019-09-09 Last updated: 2022-09-09Bibliographically approved
Williamsson, D., Sellgren, U. & Söderberg, A. (2019). Product architecture transition in a modular cyber-physical truck. Journal of Computing and Information Science in Engineering, 19(3), Article ID 031002.
Open this publication in new window or tab >>Product architecture transition in a modular cyber-physical truck
2019 (English)In: Journal of Computing and Information Science in Engineering, ISSN 1530-9827, E-ISSN 1944-7078, Vol. 19, no 3, article id 031002Article in journal (Refereed) Published
Abstract [en]

A modular product architecture is a strategic means to deliver external variety and internal commonality. In this paper, we propose a new clustering-based method for product modularization that integrates product complexity and company business strategies. The proposed method is logically verified by a studied industrial case, where the architecture of a heavy truck driveline is analyzed in terms of how it has evolved over a couple of decades, due to changed business strategies and the evolution of new technology. The presented case indicates that the new methodology is capable of identifying and proposing reasonable module candidates that address product complexity as well as company-specific strategies. Furthermore, the case study clearly shows that the business strategic reasons for a specific architecture can be found by analyzing how sensitive the clusters are to changes in the module drivers (MD).

Place, publisher, year, edition, pages
American Society of Mechanical Engineers (ASME), 2019
Keywords
business strategy, clustering, complexity, DSM, integrated modularization, MFD, product architecting, Cyber Physical System, Modular construction, Strategic planning, Trucks, Modularizations, Architecture
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-252515 (URN)10.1115/1.4042961 (DOI)000478718200003 ()2-s2.0-85063151382 (Scopus ID)
Note

QC 20190710

Available from: 2019-07-10 Created: 2019-07-10 Last updated: 2024-01-10Bibliographically approved
Andersson, K., Hagnestål, A. & Sellgren, U. (2018). A flexible chain proposal for winch based point absorbers. In: Proceedings of the ASME 2018 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference IDETC/CIE 2018: August 26-29, 2018, Quebec City, Quebec, Canada. Paper presented at ASME 2018 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference.
Open this publication in new window or tab >>A flexible chain proposal for winch based point absorbers
2018 (English)In: Proceedings of the ASME 2018 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference IDETC/CIE 2018: August 26-29, 2018, Quebec City, Quebec, Canada, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Ocean wave power is a promising renewable energy source for future energy production. It has however been difficult to find a cost-effective solution to convert the wave energy into electricity. The harsh marine environment and the fact that wave power is delivered with high forces at low speeds makes design of durable mechanical structures and efficient energy conversion challenging. The dimensioning forces strongly depend on the wave power concept, the Wave Energy Converter (WEC) implementation and the actual Power TakeOff (PTO) system. A WEC using a winch as a Power Take-Off system, i.e. a Winch Based Point Absorber (WBPA), could potentially accomplish a low Levelized Cost Of Energy (LCOE) if akey component - a low-cost, durable and efficient winch that can deal with high loads - can be developed. A key problem for achieving a durable winch is to find a force transmitting solution that can deal with these high loads and handle up to 80 million cycles. In this article we propose a design solution for a force transmitting chain in a WBPA system where elastomeric bearings are used as a means to achieve the relative motion between the links in the chain. With this solution no sliding is present and the angular motion is achieved as a deformation in the elastomeric bearing when the chain is winded on a drum. The link was designed primarily to minimize the number of joints in the chain: Thereby the maximum allowed relative angle between the links when rolled up over the drum should be as large as possible within practical limits. The angle is to be handled by the elastomeric bearing. A detailed strength analysis of the link has been performed as well as topology optimization to increase the strength to weight ratio. A test rig for a first proof of concept testing has been developed and the first preliminary test results indicate that this concept with using elastomeric bearings can be a potential solution for a durable chain and should be analyzed further for fatigue conditions and under water operations. 

Keywords
Chain transmission; Elastomeric bearing; Power take-off system; Wave power
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-240567 (URN)10.1115/DETC2018-85828 (DOI)000461131000020 ()2-s2.0-85056899645 (Scopus ID)
Conference
ASME 2018 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference
Note

QC 20190107

Available from: 2018-12-19 Created: 2018-12-19 Last updated: 2022-09-09Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-9857-8091

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