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In the literature, no studies correlate the effects of mandibular advancement devices (MADs) with different titration systems to periodontitis. Through a finite element analysis (FEA), this study investigates the effects generated on periodontal ligaments (PDLs) and teeth by four commercial MADs in periodontal health and with 15% bone resorption.

ABSTRACTObjectiveThe study aims to evaluate the stresses and the deformations generated at the periodontal level by two mandibular advancement devices (MADs) using finite element analysis.MethodsA three-dimensional digital model of the skull of a 29-year-old patient was created using a CBCT. The 3D models of two MADs (Somnodent FlexTMand Somnodent AvantTM) were reconstructed from scanning prototypes based on the patient’s anatomy. The overall geometry was imported into software for the finite element study. A force of 11.18 N representing an advancement of 9.5 mm was applied to the devices. A finite element analysis wfas subsequently performed.ResultsSomnodent FlexTMgenerates a peak of 3.27 kPa on periodontal ligaments and 287 kPa on teeth. For Somnodent AvantTMthe maximum stress is 4.53 kPa on periodontal ligaments and 467 kPa on teeth.ConclusionDifferent activation mechanisms of the devices generate stresses of different entities.

Environmental sustainability-oriented design is becoming increasingly important in the industrial field partly because of the effects of climate change. Sustainable development-oriented choices are most effective at the early design stage. The design team must be able to assess approximately and quickly the environmental impact early in the design phase. From these motivations comes the need for a method that quickly and with few parameters can estimate the product environmental impact during the conceptual design phase. Machine learning techniques appear to be well suited to meet this challenge. Machine learning is an established research topic in Industry 4.0 and its adoption is increasing. The integration of machine learning within conceptual design quickly facilitates the approximate assessment of environmental impact through high-level data. In this paper, a method is proposed to obtain a parametric model for the environmental impact assessment of manufacturing components at the early design stage. It allows consistent considerations concerning environmental matters, albeit little information available during design phase.

ABSTRACTDesign for Manufacturing and Assembly (DfMA) is a consolidated engineering activity that suffers a real integration with 3D CAD systems. DfMA principles are currently applied downstream of the 3D modelling, by following the well-known rules available from the literature and company’s know-how. The paper provides a method to acquire, elaborate and represent DfMA rules sets to aid designers and engineers in developing mechanical products. This research work wants to define a general method able to couple DfMA design guidelines (knowledge-based design) with geometrical product features available by the investigation of the 3D model. The analysis of the 3D CAD model allows to anticipate manufacturing issues and to control manufacturing cost during product design. Moreover, a framework to embed this approach within a 3D CAD system is presented for future development in a software tool. Two case studies, a simple casing made of six parts and a centrifugal pump made of sixty-eight parts, highlight how the proposed method allows easy deployment of this approach in DfMA projects. Several benefits are recognized: (i) anticipation of manufacturing and assembly issues, (ii) reduction of manufacturing and assembly cost and, (iii) reduction of effort and time required by designers during the product development process.

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The die manufacturing industry is widely based on the use of conventional machining tools. However, several studies have proposed Additive Manufacturing (AM) for molds and die inserts in the last ten years. The AM flexibility allows designing and manufacturing complex surfaces. This flexibility can be used to optimize the cooling channels of die inserts (conformal cooling). The research aims to evaluate whether Design for Additive Manufacturing commercial tools can be employed in redesigning die inserts. Besides, the paper describes a method to redesign a die insert for High-Pressure Die Casting using Selective Laser Melting. A test case is proposed to analyze an AM die insert’s redesign process for improving the thermal exchange and the material distribution. The simulation of the AM process supports the drafting conclusions from the results.

The paper proposes a method to couple manufacturing knowledge in the context of casting with 3D CAD modelling and design. The approach allows formalizing tacit into explicit design knowledge, for aiding engineers during the development of metal casted components. It is based on three main pillars: (i) identification of geometrical features (3D CAD features) and parameters that can cause an issue during the manufacturing process, (ii) definition of a numerical threshold for feature parameters that guarantee the feasibility of the casting process, and (iii) representation of design rules within a CAD system to support product design review. The method is considered the starting point for future developing a software tool (CAD tool plug-in), here just presented. Two case studies are reported with the aim to show the advantages of the proposed method and tool in the identification of manufacturing issues early in the product development process. Results highlight how the CAD-based tool is a useful assistant to avoid design problems related to the metal casting process.

Design for disassembly is a key enabling strategy for the development of new business models based on the Industry 4.0 and circular economy paradigms. This paper attempts to define a method, based on Data Mining, for modelling disassembly data from large amount of records collected through the observation of de-manufacturing activities. The method allows to build a repository to characterize the disassembly time of joining elements (e.g. screws, nuts) considering different features and conditions. The approach was preliminary tested on a sample of 344 records for nuts disassembly retrieved by in-house tests. Disassembly time and corrective factors were assessed including the analysis of probability distribution function and standard deviation for each feature (i.e. disassembly tool).

One of the most important drivers for developing competitive products is cost. However, scientific and industrial communities are missing an effective cost management framework (including a solid method and a reliable tool) for supporting the product development process, from the initial design phases to procurement. For this reason, the paper presents a holistic 'should costing' methodology able to foster collaboration on cost-oriented solutions among company's departments. The 'should costing' methodology and the related tool enable a systematic review of cost evolution, focusing on the opportunities to reduce costs, from the conceptual design stage through the overall production stages. In addition, the paper presents requirements for efficient implementation of a should-cost tool considering enterprise software solutions already available in manufacturing companies. A couple of companies (product manufacturers) adopted the recommended 'should costing' framework and quantitative and qualitative evaluations of the deployment process are presented as results. The benefits related with the adoption of the proposed should costing approach in relation with the traditional product development process is presented as well.

Welding is considered an energy-intensive manufacturing system and it represents one of the most impacting construction process. The paper aims to define a structured data framework for life cycle inventory of a welding process starting from engineering and design documentation. The use of design documentation allows to perform robust LCA analysis which permits to compare the environmental performances of the most widely used welding technologies early in the design process. The necessary information to fill the data framework can be retrieved by available documentation developed in the preliminary design phase allowing to anticipate the life cycle analysis before the construction phase. A ship hull structure designed to be manufactured by the use of GMAW and GTAW welding processes has been analyzed as case study. The use of data framework facilitates the inventory phase creating a consistent and robust inventory for LCA.

Hot forging is an industrial process where a metal piece is formed through a series of dies which permanently change the shape of the part. Open-die forging is a particular type of hot forging in which the used dies are generally flat and the part to be formed has a simple shape. Manufacturing cost estimation is a well-debated topic, especially for traditional manufacturing technologies. However, only few models are available in scientific literature for the open-die forging process. This lack is due to the complexity of the process, characterized by a low level of automation and a high degree of expertise required to develop the process. The paper proposes an analytical model for the cost estimation of axisymmetric components realized using open die-forging. The model uses as input the geometrical features of the part (e.g. dimensions, shape, material and tolerances), and gives as output: (i) the time required for the process development, (ii) the amount of material needed for the part processing and, (iii) the forging machine size/type, from the cutting of the billet to the piece deformation. Two cylindrical discs have been analysed for validating the proposed cost estimation model. The case studies show that the cost models give an accurate result in terms of cost breakdown, allowing the designer a quick calculation of process costs.

Promoting a more sustainable and energy-saving economy is one of the main goal of the European Community. In this context, home appliance manufacturers are researching and developing more efficient and sustainable products. Home automation and smart objects, by implementing specific energy management strategies, can significantly reduce energy waste. This paper aims to investigate the benefits offered, in terms of environmental impacts, by a smart system for kitchen air treatment. The system is composed by two inter-connected smart devices: a kitchen hood and an additional aspiration system able to assure a constant indoor comfort minimizing energy consumption and heat losses. Three different configurations were analyzed and compared: conventional extractor kitchen hood, smart extractor kitchen hood, and smart filtrating kitchen hood with smart additional aspiration system. Results show that in comparison with a traditional hood, products equipped with smart devices present lower environmental impact, due to the optimization of their energy consumptions.

Maritime vessels are complex products with long service life and great costs of building, manning, operating, maintaining and repairing. The paper aims to introduce a specific life cycle model and related metrics in shipbuilding design, supporting decision-making processes of material selection, manufacturing/assembly practices, maintenance, use, etc. The model provides a common structure for life cycle assessment (LCA) and life cycle cost analysis (LCCA) including the way to retrieve and to collect necessary data for the analysis starting from the available project documentation and design models. Different design configurations (materials, welding methods, etc.) for hull and hatches of a luxury yacht have been analysed using the proposed model.

The paper presents a lifecycle approach and the related software tool for the analysis and management of resource consumptions and environmental impacts of manufacturing plants. The approach, based on the industrial metabolism model, takes into account all the production and assembly aspects. The tool is able to assess the optimum working conditions for the minimization of resource consumptions (e.g. electricity) or environmental emissions (e.g. CO2). It provides a tangible support to guide decision-making strategies to move manufacturing towards sustainability. A manufacturing plant has been analysed for the model validation and the management of production scenarios, optimizing environmental and energy loads.

Electronics plays an essential role in many products and this leads to a larger production of e-wastes, currently recovered through impactful recycling processes. This paper proposes a web-based platform to implement reuse scenarios for electronic components. The objective is to create a structured portal where all the stakeholders can collaborate to extend the components lifespan and implement new circular business models. The final goal is to “close the gap” between the beginning and the end of life. The case study (industrial application) shows relevant benefits for the involved electronics manufacturer both in terms of environmental impact and economic savings.

Conceptual design is a crucial activity in the product development process. The design freedom must consider a trade-off analysis among several aspects such as assembly, manufacturing, and costs. The goal of this approach is to define a multi-objective design approach for the determination of feasible design options. The approach is grounded on the concept of functional basis for the analysis of product modules and the theory of Multi Criteria Decision Making (MCDM) approach for the assessment of the best design option. A complex product (tool-holder carousel of a machine tool) is used as a case study to validate the approach.

Design-for-Assembly (DfA) and Conceptual DfA criteria are used in the generation of cost-effective assembly sequences for complex products. The design freedom suggests optimal solutions in the assembly time minimization problem regardless costs and issues about materials and manufacturing processes selection. The goal of this approach is to investigate how the application of the conceptual DfA affects the material and manufacturing costs (Design-to-Cost). A complex product (tool-holder carousel of a CNC machine) is used as a case study. The outcome is an approach to support designers and engineers in the re-design process for the product development and cost reduction.

Nowadays, a large number of goods (e.g. appliances and electronic products) must be treated in dismantling centers after the conclusion of their lifecycle. Selective disassembly is necessary to accomplish environmental directives and to increase their sustainability. Dismantling centers developed internal non-standardized procedures to remove dangerous components and to minimize disassembly costs. The proposed approach aims to create a collection of the disassembly knowledge coming from dismantling centers as a repository for design actions oriented to End-of-Life. The final goal is to define a knowledge-based Design for Disassembly approach to support companies in designing products with improved disassemblability and maintainability.

The paper presents a lifecycle approach applied to the whole factory plant to characterize primary resource consumptions and environmental impacts for the different processes. The method is based on specific environmental models, defined for each process of a manufacturing plant. The goal is to provide a tangible support to guide decision-making strategies in order to move manufacturing towards sustainability. A case study of a washing machine factory plant has been analyzed to highlight the critical working areas in terms of environmental and energy loads and to support the identification of the corrective actions to increase the overall sustainability.

The adoption of an eco-design approach is a key challenge for the total quality environmental management (TQEM). Recently, several eco-design methodologies have been presented, but none can be easily integrated in the traditional design process of manufacturing companies. The research presented in this paper aims to define a methodology, called G.EN.ESI, to help designers (especially those ones without a specific know-how on eco-design), during the development of sustainable products. In order to aid designers in the assessment of the environmental and cost impacts of a product, also a set of software tools have been defined. Using such a platform, the designer is supported by a robust workbench to perform all the analyses required to evaluate the product eco-sustainability for each phase of the product lifecycle. This software platform is essential for companies which want to implement the G.EN.ESI methodology without upsetting their own consolidated modus operandi and the internal organisation.

In order to favor the implementation of closed-loop scenarios at the product End of Life (EoL), it is essential to consider the disassembly phase during the design process. In this context, the paper presents a design for disassembly approach to quantitatively estimate the product disassemblability. The methodology is based on a knowledge database about liaisons, which have been classified and characterized with different properties, in order to take into account the liaison specificity and real conditions in the moment of the disassembly. Starting from the product structure and liaisons between components, the methodology allows to analytically calculate the disassembly time and cost of components/sub-assemblies. The case study (combination oven) demonstrates the usefulness of the proposed approach in identifying the product criticalities which is necessary to consider during the redesign phase in order to improve the product disassemblability performances.

This paper presents a method to evaluate the environmental and economical sustainability of a manufacturing line/plant along its whole life cycle. The concurrent analysis of LCA and LCC allows the process engineers to estimate the production sustainability during the design of a new production line. The method considers costs and environmental impacts of the initial deployment (i.e. initial investment and set-up), use (i.e. workload or maintenance required by each machine) and end of life (i.e. retirement) of the analyzed system. The approach has been tested in a company that manufactures extruded pipes with the aim to evaluate the relative benefits.

Collaborative product design favours the identification of innovative solutions as well as enriching the experience of those who participate. Nevertheless, the design and supply chain integration in product development processes is not a trivial task. The main difficulties are related to the different levels of individual expertise amongst team members and to the different organisation of the companies involved. The complex scenario of the extended enterprise triggers research toward the development of efficient methods and tools to support the design teamwork. The present article illustrates an innovative co-design platform which implements an approach to support dynamic collaborative design processes. Starting from the definition of a new design process model integrating different collaborative dimensions, the proposed approach is based on the formalisation of the distributed knowledge in terms of interaction rules and representational models. In particular, the process variability is managed through a new dynamic workflow system able to handle unpredictable events occurring when multiple partners collaborate. Case Based Reasoning algorithms (CBR) are used to manage unexpected events. They support the identification of existing rules in order to reconfigure the workflow. Experimentation is carried out in order to identify the main advantages of the system and also critical issues.

3D CAD systems are powerful tools for modelling rigid bodies but they are not adequate in order to model flexible material components, especially if a realistic simulation of physical behaviour is required as in virtual prototyping. This paper describes the methodology used to develop a knowledge-based system in order to automatically create virtual prototypes of uniaxial flexible components like cables, pipes and wires. The method has been translated in an operative design software system for metallic-reinforced elastomer hoses. The resulting VP tool integrates the 3D CAD technology and suitable structural simulation methods. The robustness of software system has been verified and errors are assessed. A dedicated experimental set-up has been realised in order to compare the virtual results with the real component behaviour. The system has been applied in the design of multifunctional agricultural machines showing reduction of physical prototypes and the lead-time due.