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Research and Development Unit for Mechanical and Industrial Engineering
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An Alternative Digital Image Correlation-Based Experimental Approach to Estimate Fracture Parameters in Fibrous Soft Materials
Publication . Filho, João; Xavier, José; Nunes, Luiz; UNIDEMI - Unidade de Investigação e Desenvolvimento em Engenharia Mecânica e Industrial; DEMI - Departamento de Engenharia Mecânica e Industrial; Molecular Diversity Preservation International (MDPI)
One of the main challenges in experimental fracture mechanics is to correctly estimate fracture parameters of a nonhomogeneous and nonlinear material under large deformation. The crack tip detection is strongly affected by fibers at crack tip, leading to inaccurate measures. To overcome this limitation, a novel methodology based on the Digital Image Correlation (DIC) method for crack tip detection of fibrous soft composites is proposed in this work. The unidirectional composite was manufactured using a matrix of polydimethylsiloxane reinforced with a single layer of extensible cotton knit fabric. For two different fiber orientations, the crack growth (da), Crack Tip Opening Displacement (CTOD) and Crack Tip Opening Angle (CTOA) were determined using pure shear specimens under mode I fracture. A consistent estimation of fracture parameters was obtained. The location of the crack tip position during the fracture test using the DIC-based methodology was validated against a visual inspection approach. Results indicated that the DIC-based methodology is easily replicable, precise and robust.
Linking the potentials of extended digital marketing impact and start-up growth
Publication . Rizvanović, Belma; Zutshi, Aneesh; Grilo, António; Nodehi, Tahereh; DEMI - Departamento de Engenharia Mecânica e Industrial; UNIDEMI - Unidade de Investigação e Desenvolvimento em Engenharia Mecânica e Industrial; Elsevier Science B.V., Amsterdam.
The contemporary market positions digital marketing as a powerful mediator between efficient digital interaction, data interpretation opportunities, and business growth, while extending its impact potential to tackle different growth challenges. As start-ups usually have limited resources and struggle with customer engagement, retention, and other growth challenges, the low investment and dynamic elements of digital marketing tools can be used to support constructive digital interactions impacting start-up growth. Consequently, these links have outlined an extended digital marketing impact in the areas which build on marketing and sales and influence growth components such as product & market testing, customer engagement, and partnership development. Through a systematic literature review, we present a holistic overview encompassing start-up growth areas that use digital marketing. We also discuss how digital marketing efforts complement the start-up maturity. Furthermore, we analyze the differences in B2B and B2C digital marketing usage and discuss how emerging technologies impact digital marketing. The link between the extended digital marketing impact, start-up challenges, and growth areas result in the identification of start-up growth drivers supported by digital marketing. We propose a Macro-Dynamic framework identifying the start-up growth drivers from product, market, team, and finance areas and digital marketing tactics connected to the identified growth drivers.
An Application of Axiomatic Design to Improve Productivity in the Circular Economy Context—The Salt Production Example
Publication . Gabriel-Santos, António; Fradinho, João; Mourão, António; Martinho, Alberto; Cavique, Miguel; Vieira, Gonçalo; Gonçalves-Coelho, António; DEMI - Departamento de Engenharia Mecânica e Industrial; UNIDEMI - Unidade de Investigação e Desenvolvimento em Engenharia Mecânica e Industrial; Molecular Diversity Preservation International (MDPI)
Sustainability and a circular economy (CE) are crucial for the development of society. The CE approach should start by designing new products or processes or retrofitting existing ones to achieve the best efficiency and extend their life cycle. Designs that enable CE require the guidance of a design theory. Axiomatic design (AD) theory allows for the classification of designs and achieving the targets if appropriate requirements are adopted. This paper aimed to show that sustainability and productivity can be made compatible by ensuring functional independence, as defined in AD and using the circular economy concept. The paper presents how a salt washing machine could be improved concerning its performance. The analysis of the existing design showed fewer design parameters than the functional requirements. A viable enhancement was the addition of one design parameter, which made it possible to control the separation and washing independently. The resulting machine retrofitting increased the production rate by 20% to 30%—the productivity and the quality of the final product was also improved. The washing process now used less water and energy. Moreover, the brine feeding system was also redesigned, so that the brine was now reused, the land use was reduced as was the operating time, and the operators now worked in a more friendly environment. The industrial case study presented in this paper is an example of how innovative engineering design that fits the design science research (DSR) with the generation of knowledge. The objective of this design solution was to increase the efficiency of the entire process and consequently increase the productivity and sustainability.
Exploring seafarers' knowledge, understanding, and proficiency in SEEMP
Publication . Hanif Dewan, Mohammud; Ahmed Mustafi, Mohitul Ameen; Matos, Florinda; Godina, Radu; DEMI - Departamento de Engenharia Mecânica e Industrial; Faculdade de Ciências e Tecnologia (FCT); UNIDEMI - Unidade de Investigação e Desenvolvimento em Engenharia Mecânica e Industrial; Elsevier
With 2.89 % of global carbon emissions caused by human activity, the maritime industry faces an imminent challenge in curbing its carbon footprint despite regulatory initiatives. As the shipping sector expands, the industry faces a projected increase in carbon emissions. Recognizing the key role of seafarers in emission reduction, this article introduces a comprehensive training framework designed to enhance awareness, knowledge, understanding, and skills for implementing energy-efficient ship operations. This study utilizes structural equation modeling to assess the effectiveness of seafarers' training on energy-efficient operation of ships (EEOS) by surveying 144 seafarers across 42 shipping companies worldwide and using structured questionnaires. This study found significant positive correlations between implementing the Ship Energy Efficiency Management Plan (SEEMP) and the training programs initiated by the International Maritime Organization (IMO) and shipping companies. The results of this study indicate that traditional institutional and specialized training programs on EEOS are relatively ineffective for seafarers in implementing SEEMP onboard ships. Furthermore, the study argues that computer and simulator-based training facilitates knowledge, understanding, and proficiency of SEEMP among seafarers more effectively than the onboard training provided by the ship's master and the chief engineer. The proposed training framework emphasizes the importance of initial training using the IMO E-Learning course and IMO “Train the Trainer” programs, followed by shipping companies' in-house training by classification societies, company project teams, and simulator-based training by service providers. The study proposes a strategic training framework that encompasses in-house training conducted by shipping companies in collaboration with partners, simulator-based training provided by specialized training providers, and ongoing onboard training facilitated by the vessel's master and chief engineer, with integration of computer-based training (CBT). This strategic approach intends to improve seafarers' competence in energy-efficient ship operations to meet predetermined carbon intensity targets, which aligns with the broader goal of leading the maritime industry toward a future of net-zero emissions.
Assessing the impact of fusion-based additive manufacturing technologies on green supply chain management performance
Publication . Ferreira, Inês A.; Oliveira, J. P.; Antonissen, Joachim; Carvalho, Helena; UNIDEMI - Unidade de Investigação e Desenvolvimento em Engenharia Mecânica e Industrial; DEMI - Departamento de Engenharia Mecânica e Industrial; CENIMAT-i3N - Centro de Investigação de Materiais (Lab. Associado I3N); DCM - Departamento de Ciência dos Materiais; Associação Portuguesa para o Estudo do Quaternário (APEQ)
Purpose: This paper aims to identify the impacts of wire and arc additive manufacturing (WAAM) technology on the green supply chain management (GSCM) performance. Also, it intends to identify the most essential WAAM capabilities. Design/methodology/approach: An exploratory case study related to a metallurgical company using WAAM technology to repair metallic components was developed. A research framework to identify WAAM production capabilities and the different GSCM performance criteria was proposed based on the current state of the art. Primary qualitative data provided evidence for developing seven propositions relating WAAM capabilities to GSCM performance. Findings: The paper provides empirical evidence relating to how WAAM production capabilities impact the different performance criteria of the GSCM performance. The results show that “relative advantage” and “supply-side benefits” are critical capabilities developed through WAAM. Furthermore, most of the capabilities regarding “relative advantage” and “supply-side benefits” promote a higher GSCM performance. Research limitations/implications: This research was carried out using a single case study research design and using qualitative data. Thus, future works are encouraged to test the propositions empirically using quantitative methodologies. Practical implications: The case study findings support that most WAAM production capabilities promote a higher GSCM performance. Managers could use this research to understand the capabilities developed by this fusion-based additive manufacturing (AM), become aware of the implications of new technology adoption on the supply chain environmental externalities, and develop new business models based on the WAAM capabilities. Originality/value: This research contributes to expanding the state-of-the art related to WAAM technology by evidencing the relationship between adopting this fusion-based AM technology and green supply chain practices. Also, it provides a set of seven propositions that could be used to theorise the impacts of WAAM adoption on the GSCM performance.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
6817 - DCRRNI ID
Número da atribuição
UIDB/00667/2020