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Amir, S., Salehi, N., Roci, M., Sweet, S. & Rashid, A. (2024). Toward a Circular Economy: A Guiding Framework for Circular Supply Chain Implementation. In: Springer Series in Supply Chain Management: (pp. 379-404). Springer Nature, 23
Open this publication in new window or tab >>Toward a Circular Economy: A Guiding Framework for Circular Supply Chain Implementation
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2024 (English)In: Springer Series in Supply Chain Management, Springer Nature , 2024, Vol. 23, p. 379-404Chapter in book (Refereed)
Abstract [en]

This chapter presents a guiding framework for circular economy implementation in supply chains. Closing the loop for resource efficiency is a well-known practice in the industry. To concretize the circular economy implementation strategies, closed-loop thinking requires innovation and adaptation. Circular supply chains (CSCs) are one of the key enablers in closing the loop by design or intention for value recovery and profit maximization. CSC is an emerging area, and the view of CSC where forward and reverse supply chain is seamlessly integrated with the overall aim to achieve system-wide circularity is missing in the academic debate. By offering a cross-functional and systemic perspective of circular supply chains, we present a guiding framework to structure and understand the underlying complexities and highlight the crucial elements of circular supply chain implementation. The framework categorizes the circular supply chain into four building blocks: systemic approach, main drivers, levels of decision making, and mechanisms to manage the full loop closure and minimize the inherent uncertainties of a complex system. We conclude the chapter by illustrating the applicability of the circular supply chain framework using two industrial cases that are transitioning toward the circular economy.

Place, publisher, year, edition, pages
Springer Nature, 2024
Series
Springer Series in Supply Chain Management, ISSN 2365-6395 ; 23
Keywords
Case study, Circular economy, Circular supply chain, Framework, Supply chain
National Category
Production Engineering, Human Work Science and Ergonomics
Identifiers
urn:nbn:se:kth:diva-346428 (URN)10.1007/978-3-031-45565-0_16 (DOI)2-s2.0-85191291806 (Scopus ID)
Note

QC 20240522

Available from: 2024-05-14 Created: 2024-05-14 Last updated: 2024-05-22Bibliographically approved
Roci, M. & Rashid, A. (2023). Economic and environmental impact of circular business models: A case study of White Goods-as-a-Service using multi-method simulation modelling. Journal of Cleaner Production, 407, Article ID 137147.
Open this publication in new window or tab >>Economic and environmental impact of circular business models: A case study of White Goods-as-a-Service using multi-method simulation modelling
2023 (English)In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 407, article id 137147Article in journal (Refereed) Published
Abstract [en]

Circular business models are gaining traction in academia and industry as an instrument to deliver environmental benefits while being economically profitable. Despite this increased interest, studies that quantitatively assess the impact of circular business models are limited. This study provides researchers and practitioners with a quantitative analysis tool to assess the dynamics of circular business models from both an economic and environmental perspective. Using the case study of white goods-as-a-service, this study employs multi-method simulation modelling in combination with statistical design and analysis of simulation experiments to investigate the effect of different factors including payment schemes (i.e., fixed fee, pay-per-use, and hybrid) and subscription contract duration (i.e., long-term, mid-term, and short-term) on the economic and environmental performance of access-based models. In addition, as the adoption of access-based models is economically challenging for manufacturers due to a discrepancy between costs and revenue streams, this study analyses the effect of different levers to improve the liquidity performance of access-based business models including deposit schemes, cancellation and collection fees, as well as partnering with financial institutions to cover the initial revenue gap. 

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
circular business models, multi-method simulation, pricing strategy, design of experiments, circular manufacturing systems, circular economy
National Category
Engineering and Technology
Research subject
Production Engineering
Identifiers
urn:nbn:se:kth:diva-321523 (URN)10.1016/j.jclepro.2023.137147 (DOI)000986013000001 ()2-s2.0-85152602643 (Scopus ID)
Note

QC 20230530

Available from: 2022-11-17 Created: 2022-11-17 Last updated: 2023-05-30Bibliographically approved
Zhao, X., Wei, Y., Mansour, R., Dadbakhsh, S. & Rashid, A. (2023). Effect of Scanning Strategy on Thermal Stresses and Strains during Electron Beam Melting of Inconel 625: Experiment and Simulation. Materials, 16(1), Article ID 443.
Open this publication in new window or tab >>Effect of Scanning Strategy on Thermal Stresses and Strains during Electron Beam Melting of Inconel 625: Experiment and Simulation
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2023 (English)In: Materials, E-ISSN 1996-1944, Vol. 16, no 1, article id 443Article in journal (Refereed) Published
Abstract [en]

This paper develops a hybrid experimental/simulation method for the first time to assess the thermal stresses generated during electron beam melting (EBM) at high temperatures. The bending and rupture of trusses supporting Inconel 625 alloy panels at similar to 1050 degrees C are experimentally measured for various scanning strategies. The generated thermal stresses and strains are thereafter simulated using the Finite-Element Method (FEM). It is shown that the thermal stresses on the trusses may reach the material UTS without causing failure. Failure is only reached after the part experiences a certain magnitude of plastic strain (similar to 0.33 +/- 0.01 here). As the most influential factor, the plastic strain increases with the scanning length. In addition, it is shown that continuous scanning is necessary since the interrupted chessboard strategy induces cracking at the overlapping regions. Therefore, the associated thermal deformation is to be minimized using a proper layer rotation according to the part length. Although this is similar to the literature reported for selective laser melting (SLM), the effect of scanning pattern is found to differ, as no significant difference in thermal stresses/strains is observed between bidirectional and unidirectional patterns from EBM.

Place, publisher, year, edition, pages
MDPI AG, 2023
Keywords
thermal distortion, scanning strategy, electron beam melting (EBM), additive manufacturing simulation
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:kth:diva-323428 (URN)10.3390/ma16010443 (DOI)000908817600001 ()36614787 (PubMedID)2-s2.0-85145774044 (Scopus ID)
Note

QC 20230201

Available from: 2023-02-01 Created: 2023-02-01 Last updated: 2024-03-18Bibliographically approved
Zeyu, L., Dadbakhsh, S. & Rashid, A. (2023). Increasing precision towards NiTi lattice structure using PBF-EB. In: : . Paper presented at 34th Annual Symposium: Solid Freeform Fabrication, August 14-16, 2023, Austin, Texas, United States of America.
Open this publication in new window or tab >>Increasing precision towards NiTi lattice structure using PBF-EB
2023 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

The electron beam powder bed fusion (PBF-EB) is limitedly used to manufacture complex structures such as delicate lattices. Nickel titanium (NiTi) has been chosen for fabricating the lattice structure due to its widely utilization in the biomedical sector. However, issues may arise when manufacturing angled trusses while the dimensional inaccuracy increased with the increasing of the angle between the truss member and the vertical build direction. Therefore, two different scan strategies: spot melting and linear melting were used to manufacture the lattice structures respectively to compare the dimensional accuracy of different structures. This investigation highlights that linear melting is prone to maintain the geometrical accuracy of line-based structure with a limited influence from the scan speed while the spot melting is more capable of manufacturing the point-based structure with a higher geometrical resolution.  

National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-336584 (URN)
Conference
34th Annual Symposium: Solid Freeform Fabrication, August 14-16, 2023, Austin, Texas, United States of America
Note

QC 20230915

Available from: 2023-09-13 Created: 2023-09-13 Last updated: 2023-09-15Bibliographically approved
Lin, Z., Surreddi, K. B., Hulme-Smith, C., Dadbakhsh, S. & Rashid, A. (2023). Influence of Electron Beam Powder Bed Fusion Process Parameters on Transformation Temperatures and Pseudoelasticity of Shape Memory Nickel Titanium. Advanced Engineering Materials
Open this publication in new window or tab >>Influence of Electron Beam Powder Bed Fusion Process Parameters on Transformation Temperatures and Pseudoelasticity of Shape Memory Nickel Titanium
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2023 (English)In: Advanced Engineering Materials, ISSN 1438-1656, E-ISSN 1527-2648Article in journal, Editorial material (Refereed) Published
Abstract [en]

Electron beam powder bed fusion (PBF-EB) is used to manufacture dense nickel titanium parts using various parameter sets, including the beam current, scan speed and post cooling condition. The density of manufactured NiTi parts are investigated with relation to the linear energy input. The results implies the part density increases with increasing linear energy density to over 98% of the bulk density. With a constant energy input, a combination of low power and low scan speed leads to denser parts. This is attributed to lower electrostatic repulsive forces from lower number density of the impacting electrons. After manufacturing, densest parts with distinct parameter sets are categorized into three groups: i) high power with high scan speed and vacuum slow cooling, ii) low power with low scan speed and vacuum slow cooling and iii) low power with low scan speed and medium cooling rate in helium gas. Among these, a faster cooling rate suppresses phase transformation temperatures, while vacuum cooling combinations do not affect the phase transformation temperatures significantly. All the printed parts in this study exhibit almost 8% pseudoelasticity regardless of the process parameters, while the parts cooled in helium have a higher energy dissipation efficiency ( ), which implies faster damping of oscillations. 

Place, publisher, year, edition, pages
John Wiley & Sons, 2023
Keywords
PBF-EB, cooling rate, NiTi, AM, process paremeters
National Category
Materials Engineering
Research subject
Industrial Engineering and Management
Identifiers
urn:nbn:se:kth:diva-326103 (URN)10.1002/adem.202201818 (DOI)000975548500001 ()2-s2.0-85154049056 (Scopus ID)
Note

QC 20230426

Available from: 2023-04-24 Created: 2023-04-24 Last updated: 2023-11-30Bibliographically approved
Holmberg, J., Berglund, J., Brohede, U., Åkerfeldt, P., Sandell, V., Rashid, A., . . . Hosseini, S. (2023). Machining of additively manufactured alloy 718 in as-built and heat-treated condition: surface integrity and cutting tool wear. The International Journal of Advanced Manufacturing Technology, 130(3-4), 1823-1842
Open this publication in new window or tab >>Machining of additively manufactured alloy 718 in as-built and heat-treated condition: surface integrity and cutting tool wear
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2023 (English)In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 130, no 3-4, p. 1823-1842Article in journal (Refereed) Published
Abstract [en]

Additive manufacturing (AM) using powder bed fusion is becoming a mature technology that offers great possibilities and design freedom for manufacturing of near net shape components. However, for many gas turbine and aerospace applications, machining is still required, which motivates further research on the machinability and work piece integrity of additive-manufactured superalloys. In this work, turning tests have been performed on components made with both Powder Bed Fusion for Laser Beam (PBF-LB) and Electron Beam (PBF-EB) in as-built and heat-treated conditions. The two AM processes and the respective heat-treatments have generated different microstructural features that have a great impact on both the tool wear and the work piece surface integrity. The results show that the PBF-EB components have relatively lower geometrical accuracy, a rough surface topography, a coarse microstructure with hard precipitates and low residual stresses after printing. Turning of the PBF-EB material results in high cutting tool wear, which induces moderate tensile surface stresses that are balanced by deep compressive stresses and a superficial deformed surface that is greater for the heat-treated material. In comparison, the PBF-LB components have a higher geometrical accuracy, a relatively smooth topography and a fine microstructure, but with high tensile stresses after printing. Machining of PBF-LB material resulted in higher tool wear for the heat-treated material, increase of 49%, and significantly higher tensile surface stresses followed by shallower compressive stresses below the surface compared to the PBF-EB materials, but with no superficially deformed surface. It is further observed an 87% higher tool wear for PBF-EB in as-built condition and 43% in the heat-treated condition compared to the PBF-LB material. These results show that the selection of cutting tools and cutting settings are critical, which requires the development of suitable machining parameters that are designed for the microstructure of the material.

Place, publisher, year, edition, pages
Springer Nature, 2023
National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-342428 (URN)10.1007/s00170-023-12727-w (DOI)001122504100001 ()2-s2.0-85179663025 (Scopus ID)
Funder
Vinnova, 2016-05175Swedish Foundation for Strategic Research, GMT14-048Swedish Research Council, 2016-05460
Note

QC 20240122

Available from: 2024-01-18 Created: 2024-01-18 Last updated: 2024-01-22Bibliographically approved
Zeyu, L., Dadbakhsh, S. & Rashid, A. (2022). Developing processing windows for powder pre-heating in electron beam melting. Journal of Manufacturing Processes, 83, 180-191
Open this publication in new window or tab >>Developing processing windows for powder pre-heating in electron beam melting
2022 (English)In: Journal of Manufacturing Processes, ISSN 1526-6125, Vol. 83, p. 180-191Article in journal (Refereed) Published
Abstract [en]

Powder pre-heating is a critical step in electron beam melting (EBM), while there has been no systematic work tostudy the corresponding processing windows so far. Accordingly, this work investigates the relation between thesintering and the issues appearing during pre-heating (e.g., smoking or excessive sintering) in EBM of highlysusceptible-to-smoke Nickel-Titanium (NiTi) powder. First, the EB spot size was assessed depending on differentfocus offsets and beam currents from beam tracking experiments on a ceramic-coated stainless steel plate. Af-terwards, the smoke tests were carried out at different focus offsets and beam currents in terms of beam speeds. Itis shown that a smaller EB spot can effectively prevents smoking by enhancing the sintering degree. However,since this high sintering degree can cause strong powder bonding preventing the powder recycling, less focusedbeam (or larger EB spot) was selected to reach medium but efficient sintering in the level of around 30 %.Moreover, due to the influence of the diverging angle on the EB-material interaction, it is found that the negativedefocused EB mitigates the smoke phenomenon compared to the positive defocused EB with a similar spot size.Based on the smoke test results, linked to the sintering degree, the processing windows for pre-heating NiTipowder are developed demonstrating three different modes: smoke-heating, melting-heating and healthy-heating. 

Place, publisher, year, edition, pages
Elsevier BV, 2022
National Category
Engineering and Technology Production Engineering, Human Work Science and Ergonomics
Research subject
Production Engineering
Identifiers
urn:nbn:se:kth:diva-317459 (URN)10.1016/j.jmapro.2022.08.063 (DOI)000870827000003 ()2-s2.0-85137722020 (Scopus ID)
Note

QC 20220930

Available from: 2022-09-12 Created: 2022-09-12 Last updated: 2023-11-30Bibliographically approved
Zhao, X., Yuan, W., Mansour, R., Dadbakhsh, S. & Rashid, A. (2022). Effect of scanning strategy on thermal stresses and strains during electron beam melting of Inconel 625: experiment and simulation.
Open this publication in new window or tab >>Effect of scanning strategy on thermal stresses and strains during electron beam melting of Inconel 625: experiment and simulation
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2022 (English)In: Article in journal (Other academic) Submitted
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:kth:diva-312412 (URN)
Note

QCR 20220523

Available from: 2022-05-18 Created: 2022-05-18 Last updated: 2024-01-17Bibliographically approved
Roci, M., Salehi, N., Amir, S., Abdullah Asif, F. M., Shoaib-ul-Hasan, S. & Rashid, A. (2022). Multi-method simulation modelling of circular manufacturing systems for enhanced decision-making. MethodsX, 9, 101709-101709, Article ID 101709.
Open this publication in new window or tab >>Multi-method simulation modelling of circular manufacturing systems for enhanced decision-making
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2022 (English)In: MethodsX, ISSN 1258-780X, E-ISSN 2215-0161, Vol. 9, p. 101709-101709, article id 101709Article in journal (Refereed) Published
Abstract [en]

Circular manufacturing systems (CMS) constitute complex value networks comprising a large and diverse set of stakeholders that collaborate to close the loop of products through multiple lifecycles. Complex systems modelling and simulation play a crucial role in providing quantitative and qualitative insights into the behaviour of such systems. In particular, multi-method simulation modelling that combines agent-based, discrete-event, and system dynamics simulation methods is considered more suitable to model and simulate CMS as it allows to capture their complex and dynamic nature. This paper provides a step-by-step approach on how to build a CMS multi-method simulation model in order to assess their economic, environmental, and technical performance for enhanced decision-making. To model and simulate CMS three main elements need to be considered: • A multi-method model architecture where the CMS stakeholders with heterogeneous characteristics are modelled individually as autonomous agents using agent-based, discrete-event, and system dynamics. • An agent environment defined by a Geographic Information System (GIS) to establish connections based on agents’ geographic location. • The product journey resulting from the product's interaction with various CMS stakeholders in the circular value network is traced throughout its multiple lifecycles.

Place, publisher, year, edition, pages
Elsevier, 2022
Keywords
Circular economy, Circular manufacturing systems, Multi-method simulation, Complex adaptive systems, Agent-based, Discrete-event, System dynamics
National Category
Other Engineering and Technologies
Research subject
Industrial Engineering and Management
Identifiers
urn:nbn:se:kth:diva-312507 (URN)10.1016/j.mex.2022.101709 (DOI)001094795300004 ()2-s2.0-85129479239 (Scopus ID)
Note

QC 20220519

Available from: 2022-05-19 Created: 2022-05-19 Last updated: 2024-03-18Bibliographically approved
Hira, A., Pacini, H., Pereira, A. S., Attafuah-Wadee, K., Rashid, A., Gara, F. & Munene, K. (2022). Shifting to Circular Manufacturing in the Global South: Challenges and Pathways. Journal of Developing Societies, 38(3), 310-335
Open this publication in new window or tab >>Shifting to Circular Manufacturing in the Global South: Challenges and Pathways
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2022 (English)In: Journal of Developing Societies, ISSN 0169-796X, E-ISSN 1745-2546, Vol. 38, no 3, p. 310-335Article in journal (Refereed) Published
Abstract [en]

As the Global South shifts towards increased manufacturing, the negative effects on climate change and environmental pollution raise serious concerns. These global effects are increasingly felt locally, as reflected in health surveys throughout the Global South. The world cannot afford to wait for a natural development process to take place in which rising incomes might curb pollution. This article examines the challenges of reforming manufacturing in the Global South towards more sustainable practices. It also focuses on the lessons of the Sustainable Manufacturing and Environmental Pollution Program (SMEP) which has funded a series of environmental improvement projects across sub-Saharan Africa and South Asia aimed at reducing pollution in the manufacturing process. The lessons learned from these projects include the need to improve the tracking of the negative effects of the environmental damages caused by manufacturing and analyze the manufacturing supply chain processes to better identify potential points of intervention; as well as the need for more external financial and technical resources to expand these projects. 

Place, publisher, year, edition, pages
SAGE Publications, 2022
Keywords
batteries, environment, intervention, Manufacturing, pollution, South Asia, sub-Saharan Africa, supply chains, textiles, atmospheric pollution, climate change, environmental technology, fuel cell, supply chain management, textile industry, Africa, Asia
National Category
Production Engineering, Human Work Science and Ergonomics
Identifiers
urn:nbn:se:kth:diva-325992 (URN)10.1177/0169796X221107217 (DOI)000824995100001 ()2-s2.0-85134349586 (Scopus ID)
Note

QC 20230421

Available from: 2023-04-21 Created: 2023-04-21 Last updated: 2023-04-21Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-5960-2159

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