Digital Twin for maintenance: A literature review

This review presents a perspective on the research trends and solutions from recent years in the domain of antimicrobial packaging materials. The antibacterial, antifungal, and antioxidant activities can be induced by the main polymer used for packaging or by addition of various components from natural agents (bacteriocins, essential oils, natural extracts, etc.) to synthetic agents, both organic and inorganic (Ag, ZnO, TiO2 nanoparticles, synthetic antibiotics etc.). The general trend for the packaging evolution is from the inert and polluting plastic waste to the antimicrobial active, biodegradable or edible, biopolymer film packaging. Like in many domains this transition is an evolution rather than a revolution, and changes are coming in small steps. Changing the public perception and industry focus on the antimicrobial packaging solutions will enhance the shelf life and provide healthier food, thus diminishing the waste of agricultural resources, but will also reduce the plastic pollution generated by humankind as most new polymers used for packaging are from renewable sources and are biodegradable. Polysaccharides (like chitosan, cellulose and derivatives, starch etc.), lipids and proteins (from vegetal or animal origin), and some other specific biopolymers (like polylactic acid or polyvinyl alcohol) have been used as single component or in blends to obtain antimicrobial packaging materials. Where the package’s antimicrobial and antioxidant activities need a larger spectrum or a boost, certain active substances are embedded, encapsulated, coated, grafted into or onto the polymeric film. This review tries to cover the latest updates on the antimicrobial packaging, edible or not, using as support traditional and new polymers, with emphasis on natural compounds.

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Biodegradable Antimicrobial Food Packaging: Trends and Perspectives

Digital twin and its implementations in the civil engineering sector

Additive manufacturing is increasingly of interest for commercial and military applications due to its potential to create novel geometries with increased performance. For additive manufacturing to find commercial application, it will have to be cost competitive against traditional processes such as forging. Forecasting the production costs of future products prior to large-scale investment is challenging due to the limits of traditional cost accounting’s ability to handle the systemic process implications of new technologies and cognitive biases in humans’ additive and systemic estimates. Leveraging a method uniquely suited to these challenges, we quantify the production and use economics of an additively-manufactured versus a traditionally forged GE engine bracket for commercial aviation with equivalent performance. Our results show that, despite the simplicity of the engine bracket, when taking into account part redesign for AM and the associated lifetime fuel savings of the additively-designed bracket, the additively manufactured part and design is cheaper than the forged one for a wide range of scenarios, including at higher volumes of 2,000 to 12,000 brackets per year. Opportunities to further reduce costs include cheaper material prices without compromising quality, being able to produce vertical builds with equivalent performance to horizontal builds, and increasing process control so as to enable reduced testing. Given the conservative nature of our assumptions as well as our choice of part, these results suggest there may be broader economic viability for additively manufactured parts, especially when systemic factors and use costs are incorporated.

https://papers.ssrn.com/sol3/Delivery.cfm/SSRN_ID2882847_code2575183.pdf?abstractid=2815047&mirid=1

Metal Additive Manufacturing: Cost Competitive Beyond Low Volumes

Shipping is looking to progressively develop into a zero‐emissions industry, in agreement with pledges made under the Initial IMO Strategy on reduction of greenhouse gas emissions from ships, and its vision to phasing out greenhouse gas emissions as soon as possible during this century. International regulations currently focus on the design and operational phases of the industry, which carries the largest life‐cycle climate impact of a ship. As the level of emissions from the operational phase is reduced, the inclusion of emissions from shipyards during construction, maintenance, and disposal becomes increasingly important. The main objective of this study is to improve energy efficiency and reduce air emissions in the shipbuilding industry through the development of an energy‐management framework. A systematic literature review was used to define criteria for clean and green shipyards and to develop a novel, holistic, systematic, and transdisciplinary framework for energy management. The energy‐management framework is aimed at creating a decision‐support mechanism for complex situations, using a multiple criteria decision‐making approach. The energy‐management framework was applied to case studies of a Bangladeshi and an Italian shipyard. The potential implementation of the framework in yards of different sizes, types and geographical location demonstrates that it has the potential to improve energy management and thereby energy efficiency while increasing productivity and profitability in shipyards.

Energy‐related clean and green framework for shipbuilding community towards zero‐emissions: A strategic analysis from concept to case study

Using design information to create a data framework and tool for life cycle analysis of complex maritime vessels

Life Cycle Model and Metrics in Shipbuilding: How to Use them in the Preliminary Design Phases

This paper presents a novel framework for manufacturing and cost-related knowledge formalization. This artefact allows industries to capitalize the knowledge of experienced practitioners in the field of manufacturing and assembly, so that it can be used by designers for quickly and analytically estimating the production costs of components during product development. The framework consists of the following: (i) a cost breakdown structure used for splitting out the manufacturing cost, (ii) a data model (cost routing) to collect the knowledge required to define a manufacturing process, (iii) a data model (cost model) for collecting the knowledge required to compute the manufacturing cost of each operation within a manufacturing process, and (iv) a workflow to define the manufacturing process. The proposed framework provides several advantages: (i) knowledge formalization of product manufacturing cost, (ii) knowledge sharing among design/engineering departments, and (iii) knowledge capitalization for decision-making process. The proposed framework is used to formalize the knowledge required for analytically estimating the manufacturing cost of open-die forged components. Results highlight that the framework addresses the most important requirements for a knowledge-based cost estimation system.

A framework for analytical cost estimation of mechanical components based on manufacturing knowledge representation

The paper aims to analyze and compare the environmental performances of metal arc welding technologies: gas metal arc welding (GMAW), shielded metal arc welding (SMAW), gas tungsten arc welding (GTAW), submerged arc welding (SAW), and flux-cored arc welding (FCAW). Welding is considered one of the most energy-intensive processes in manufacturing. This study was performed in accordance with the international standard ISO 14040/14044 by using attributional life cycle assessment (aLCA). The functional unit is defined as the “the development of 1 metre of welding seam (qualified by ASME section IX requirements) to join 25 millimetres thick of metal plates made in carbon steel material and considering a V-bevel configuration.” Different configurations of base/filler materials and standardized bevel geometries have been analyzed as welding scenarios. The inventory considers all inputs (e.g., electric energy and filler material) and outputs (e.g., fume emissions and slags) involved in each welding process. A framework for data collection starting from available project documentation is presented as an innovative solution for the inventory phase. The impact assessment includes the human health, resources (midpoints/endpoint), and ecosystems (endpoint) categories from the ReCiPe (H) and cumulative energy demand (CED) methods. This study reveals a notable dominance in terms of the environmental burdens of GTAW and SMAW processes, as they present higher impacts in most of the impact categories. SMAW is the most energy-consuming process, and this aspect is reflected in the environmental performance. Conversely, GMAW presents the least environmental load, accounting for less than one third compared with GTAW in terms of the CED indicator and performing very well in terms of the ReCiPe endpoint indicator. Via analysis of different scenarios, the main outcomes are the following: (i) the use of V bevels significantly increases the environmental load when the metal plate thickness increases and (ii) the use of specific materials such as Inconel alloy exacerbates the environmental concerns associated with welding processes. The use of project documentation allows robust analysis of welding activity. Sensitivity analysis shows how the range of values for specific parameters (e.g., volts and amps) affects each technology in a different manner. Indeed, those ranges have a limited impact on the result accuracy (up to 20%) for more automatized welding processes (e.g., GMAW, SAW, and FCAW), in which only a small number of parameters are set by the operator, and the operator skills are less influential on the quality of the weld.

Federico Campi

Papers

Using design information to create a data framework and tool for life cycle analysis of complex maritime vessels

Life Cycle Model and Metrics in Shipbuilding: How to Use them in the Preliminary Design Phases

A framework for analytical cost estimation of mechanical components based on manufacturing knowledge representation

Comparative life cycle assessment of metal arc welding technologies by using engineering design documentation

Cost Estimation Method for Gas Turbine in Conceptual Design Phase