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Toe caps are fundamental components of safety footwear used to prevent injuries, which can be caused by falling objects. They can be realized by exploiting different materials (metal, composites, and polymers) and manufacturing processes (stamping, injection molding, compression molding, etc.). However, they have always to fulfill the stringent requirements of safety regulations. In addition, in order to guarantee ergonomic use, they must be as light as possible. It was estimated that at least 300 million pairs of safety footwear, with 600 million of toe caps, end up in landfill or are incinerated every year. This huge amount of wastes generates a high environmental impact, mainly attributable to toe caps manufacturing processes. In this context, it is important to develop new solutions aimed at minimizing the environmental impacts of toe caps manufacturing processes. Furthermore, the reuse of carbon fiber prepreg scraps has been recognized as a valid method to produce effective toe caps. In this paper, the life cycle assessment (LCA) methodology was exploited to perform a detailed analysis of the environmental impacts associated with toe caps obtained by reclaiming prepreg scraps. The results, in terms of cumulative energy demand, global warming potential, and ReCiPe endpoints, were compared to those obtained by LCA of toe caps in steel, aluminum alloy, polycarbonate, and glass fiber reinforced composite. The analysis demonstrated that toe caps in steel present the lowest environmental footprint but they are the heaviest ones. The reclaim process for carbon fiber prepreg scraps can be a valid alternative to produce sustainable and lightweight toe caps for safety footwear.

Composite materials are demonstrating the ability to face the challenge of competitive markets where high-performance, low costs, and reduced manufacturing time are mandatory. Vacuum bagging with autoclave curing is one of the most used manufacturing methods for carbon fiber composite parts. However, it shows some limitations, mainly due to manual operations and long processing time. Out-of-autoclave (OOA) methods, such as pressure bag molding (PBM), can lead to a strong reduction of the manufacturing time through the simplification of lay-up and curing phases. In this paper, a comparative analysis between the autoclave and the PBM processes has been performed, jointly considering both the economic and environmental aspects. An evaluation of the environmental impacts has been carried out following the standardized life cycle assessment (LCA) methodology. In addition, costs related to these two manufacturing techniques have been estimated through a parametric approach and successively compared. Different scenarios have been considered to take into account various production batches, mold manufacturing techniques, and end of life alternatives. The analyses show conflicting results demonstrating that a global optimum scenario does not exist and, depending on the chosen indicator and production batch, the best alternative varies. Considering only the environmental indicators, the autoclave process can be considered the most sustainable option, due to the lower consumption of energy.

Advanced materials, especially carbon fiber reinforced composites (CFRP), have gained the attention of different industries whichproduce lightweight and high-performance components. The most used manufacturing processes to realize these kinds of products are Resin Transfer Molding (RTM) and vacuum bag molding with autoclave curing. RTM is based on dry fiber technology and it appears the most promising manufacturing process to realized high-quality carbon fiber parts reducing cost and manufacturing time, especially if high pressure variants are employed. On the other hand, vacuum bag molding with autoclave curing is a very consolidated process which is, however, associated with long manufacturing time and costs as well as to low repeatability of the process due to the high labor input. Out-of-autoclave methods, such as pressure bag molding (PBM) have been developed to overcome the issues of vacuum bag molding process. From the environmental point of view, the manufacturing of CFRP components is associated with high environmental loads due to the impacts related to both raw materials and manufacturing processes. For this reason, reducing the energy consumption of production phases can lead to the development of greener CFRP products. In this context, the main scope of the present research is to evaluate and compare the environmental loads of a component for the automotive industry realized exploiting the RTM, the PBM and the bag molding processes to determine which one is eco-friendlier. This analysis has been conducted following the standard Life Cycle Assessment methodology based on a “cradle to gate” approach. In this way, the use phase and the disposal of the CFRP component have not been included in the analysis. Results have been evaluated by comparing the equivalent CO2 related to each manufacturing process.

This paper proposes a methodological approach for the multi-objective optimization of steel towers made from prefabricated cylindrical stacks that are typically used in the oil and gas sector. The goal is to support engineers in designing economical products while meeting structural requirements. The multi-objective optimization approach involves the minimization of the weights and costs related to the manufacturing and assembly phases. The method is based on three optimization levels. The first is used in the preliminary design phase when a company receives a request for proposal. Here, minimal information on the order is available, and the time available to formulate an offer is limited. Thus, parametric cost models and simplified 1-D geometries are used in the optimization loop performed by genetic algorithms. The second phase, the embodiment design phase, starts when an offer becomes an order based on the results of the first stage. Simplified shell geometries and advanced parametric cost models are used in the optimization loop, which present a restricted problem domain. In the last phase involving detailed design, a full 3-D computer-aided design model is generated, and specific finite-element method simulations are performed. The cost estimations, given the high levels of detail considered, are analytic and are performed using dedicated software.

Gas turbines consume a large volume of ambient air during in-service condition. The quality of air incoming the system is essential to the performance and longevity of a gas turbine. A filtration mechanism is employed to regulate air quality by removing contaminants. For high-powered turbines, the filter system can be composed by hundreds of single filters. Therefore, to achieve the best performance, a carefully design is needed. However, a correct sizing of the filtering houses is often complex. Their dimensions and manufacturing costs make design and experimentation difficult. Numerical modeling has been playing a crucial role in the design and optimization of complex products/systems. In literature, various methods have been proposed to reduce computational resources and speed-up the simulation process. The hypothesis of bi-dimensional flow represents one of the most used strategy in different industrial cases. Much research in recent years were focused on establishing the results accuracy of 2D simulation models compared to 3D ones. The aim of this study is to propose a method to design and optimize filter houses, which integrates, in a unique framework, 3D and 2D simulations models. The latter are exploited to speed-up the design process, reducing computational time and resources. 2D simulation models have been defined according to physically validated 3D simulations. The error in estimating the temperature, pressure and velocity fields using 2D simulation models, considering 3D ones as reference, is less than 5%. Keywords: Filter House, Computational Fluid Dynamics, CFD, Virtual Prototyping, 2D Modelling, Power Plant Gas Turbine

Advanced composite materials, especially those based on carbon fibers, have been attracting the interest of industrial companies for producing light and high-performance components. Resin Transfer Molding (RTM) and its variants have been recognized as the most promising processes to manufacture CFRP (Carbon Fiber Reinforced Polymer) products in a cost-effective way. However, recent research studies highlighted environmental concerns regarding the use of CFRP parts due to the high environmental load related to their production. In this context, the main scope of the present paper is to investigate and compare the environmental impacts of three alternative manufacturing processes for producing CFRP car hoods: RTM, High-Pressure RTM and Compression-RTM. This analysis has been carried out through the standard Life Cycle Assessment methodology. The system boundaries include all the flows related to manufacturing of the hood and an end of life. Results calculated by using the ReCiPe mid-point/end-point method suggest that the eco-friendliest variant is the Compression-RTM.

The cost reduction is one of the most spread strategy adopted by companies for guaranteeing profits in a competitive market. This paper presents an approach for the cost optimization of industrial electrical routings. The proposed optimization process consists of two levels: the arrangement of the cables within the cable trays and the 3D routing of the cable trays for connecting the modules of a product. The arrangement of the power and signal cables and the selection of the cable trays are carried out considering specific configuration rules. A genetic algorithm, coupled with the Hightower's algorithm, is used to solve the routing optimization problem. The proposed cost functions consider the raw materials and manufacturing/assembly operations. The optimization process has been used for optimizing a portion of the electric cable harness of a 43 MWe power plant with a size of 44 × 20 meters, and a total of 40,60 kilometers of cables. The optimization process let to a cost saving of about 15% compared to the design carried out with the traditional approach. Abbreviations:CTs: cable trays; CUi: hourly rate for the installation phase [€/hour]; CUrmtk: hourly rate for the k-th cost center used for transforming a semi-finished component [€/hour]; Cut: hourly rate for the test phase [€/hour]; CUtray: unitary cost of a cable tray [€]; DOE: design of experiment; GA: genetic algorithm [€]; Ic: installation cost [€]; If: installation factor [-]; PAc: cost for the preliminary analysis [€]; PAcp: percentage used for calculating the cost of the preliminary analysis [%]; RMc: cost of the raw material and relative transformation operations [€]; RMcci: cost of the i-th commercial component [€]; RMoc: percentage of the overhead costs related to the management of the raw material [%]; RMsc_scrapsj: cost of the scraps for the j-th semi-finished component [€]; RMscj: cost of the j-th semi-finished component [€]; RMtc: cost for transforming semi-finished components [€]; Tcl: commercial length of a straight cable tray [meter]; Tii,j: standard installation time for the i-th or j-th component [hour]; Tl: linear distance between two points of the wiring system that need to be connected [meter]; Trmtk: time for the k-th operation for transforming a semi-finished component [hour]; Ttk: standard test time for the k-th skid of the electrical system [hour].

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.

This paper presents an approach for the product multi-objective optimization by associating the Response Surface Methodology (RSM) and the Design of Experiments (DoE) technique with the CAD/CAE/DfC integration. The goal of this study is to empirically identify the relationships existing between the design features and the product response (stress, strain, cost, etc.). This approach integrates three different levels of analysis: optimization problem definition, virtual prototyping and design optimization. The optimization problem definition concerns in choosing the design variables, setting constrains that have to be observed and goals that have to be achieved. The virtual analysis allows defining the principal parameterization of a geometric model and simulating the performance of each configuration, at a specific working condition, while evaluating the manufacturing cost and time. The proposed approach investigates the effect of the defined parameters and noise factor on the experimental results....

Modularization is a current issue in the context of plant design. A modular system aims to reduce lead time and cost in design phases. An oil & gas plant consists of many Engineered-To-Order solutions to be submitted and approved during the negotiation phase. In this context, design tools and methods are necessary to support the design life cycle from the conceptual study to the detailed project. The paper proposes an approach to optimize the design of modularized oil & gas plants with a focus on the related steel structures. A test case shows the configuration workflow applied to a modular steel structure of about 400 tons. The modularized layout has been optimized using genetic algorithms. A Knowledge Base has been described to support the configuration phase related to the conceptual design. Design rules and metrics have been formalized from the analysis of past solutions.

This study presents an approach based on Design of Experiment (DoE) technique for the optimization of an energy recovery ventilator (ERV). This system is one of the efficient ways to enhance the thermo-hygrometric comfort without increase excessively the thermal load in domestic kitchen. However, there is a major concern, which energy recovery cannot trade off ERV's fan power consumption. The goal of this study is to obtain the information about the relation between factors and response in an empirical way. This approach integrates three different levels of analysis: the virtual prototyping, Design of Experiment (DoE) and rapid prototyping. The virtual analysis allows to define the principal parameterization of a simplified model and to simulate the performance of each configuration at working condition. The proposed approach investigates the effect of the defined parameters and noise factor on the experimental results. In particular, the applied method for DoE analysis is based on virtual experiments in according to the necessity to reduce time and costs during the early design phase. The optimum parameters configuration, which is defined by the previous step, is useful to define the geometry and the working condition of a reliable virtual model. The final level is the realization of a 3D ERV with a rapid prototyping printer. The obtained component is now evaluable at the test bench to investigate the air flow rate and the electric power consumption.

The paper proposes a methodological approach to support the multi-objective (i.e. cost and structural performance) optimization of complex systems, typical of the oil & gas sector. The complexity is managed through a double-level of optimization. The first one, based on simplified product models (1-D and 0-D), considers an analytical approach for the structural behavior and a parametric one for the cost estimation. The second level considers the use of a 3-D FEM solver for structural simulations, and an analytical tool for the cost estimation. As case study, the paper proposes the design optimization of an oil & gas chimney for gas turbines. The workflow analyzed during the case study describes the use of a multi-objective and multi-level approach to optimize cost, weigh, and structural behavior of oil & gas ducts.