OTTIMIZZAZIONE DI UNA GIUNZIONE INCOLLATA A DOPPIA SOVRAPPOSIZIONE PER SANDWICH IN COMPOSITO

Grazie alle peculiari performances meccaniche, quali soprattutto l\u2019elevata resistenza a flessione unita ad un basso peso specifico, le strutture sandwich in composito sono sempre pi\uf9 frequentemente utilizzate nella moderna progettazione industriale. Nel presente lavoro, considerando un composito sandwich con skins in vetroresina e core in PVC espanso, \ue8 stato eseguito uno studio numerico e sperimentale al fine di individuare la configurazione ottimale di una giunzione incollata a doppia sovrapposizione avente quali aderendi esterni le stesse skins del sandwich e aderendo interno costituito da un inserto in metallo o in composito. In dettaglio, previa preliminare ottimizzazione teorica della geometria della giunzione, eseguita tenendo conto delle propriet\ue0 dell\u2019adesivo e del materiale costituente l\u2019aderendo interno, la configurazione ottimale \ue8 stata individuata attraverso sistematiche prove sperimentali di trazione e flessione al variare dei principali parametri di influenza. Successive analisi numeriche eseguite in ambiente Ansys APDL, hanno evidenziato i particolari meccanismi di danneggiamento interlaminare

Development of a Vessel Scheduling Optimization Model to improve Maritime Transport sustainability

The social and economic development of the islands is generally dependent on the interconnection level with the mainland obtained through maritime transport services. When connecting many islands, the route planning is essential and typically a variety of constraints must be considered. Various optimization methods have been established to improve cost-efficiency but today environmental concerns, like the reduction of CO2 emissions, have become mandatory. This paper proposes a vessel scheduling optimization model able to simultaneously consider compulsory and optional tasks and vehicle-dependent profits. The algorithm was applied to seven islands of the Tyrrhenian Sea located in front of Sicily, named “Aeolian Islands”. Considering the regional requirements in terms of minimum number of routes and maximum fare prices for each season, this research compared the optimal vessels option obtained maximizing the profit with the one obtained minimizing the emissions. In particular, we have conducted three different analyses, in the first one we have considered only the mandatory routes while the second one was carried out identifying a series of potentially attractive additional activities based on historical demand data provided by the company that currently manages the service. Finally, the third analysis addresses a scenario where older fuel-powered vessels were replaced with hybrid electric ones

Occupational health and safety issues in human-robot collaboration: State of the art and open challenges

Human-Robot Collaboration (HRC) refers to the interaction of workers and robots in a shared workspace. Owing to the integration of the industrial automation strengths with the inimitable cognitive capabilities of humans, HRC is paramount to move towards advanced and sustainable production systems. Although the overall safety of collaborative robotics has increased over time, further research efforts are needed to allow humans to operate alongside robots, with awareness and trust. Numerous safety concerns are open, and either new or enhanced technical, procedural and organizational measures have to be investigated to design and implement inherently safe and ergonomic automation solutions, aligning the systems performance and the human safety. Therefore, a bibliometric analysis and a literature review are carried out in the present paper to provide a comprehensive overview of Occupational Health and Safety (OHS) issues in HRC. As a result, the most researched topics and application areas, and the possible future lines of research are identified. Reviewed articles stress the central role played by humans during collaboration, underlining the need to integrate the human factor in the hazard analysis and risk assessment. Human-centered design and cognitive engineering principles also require further investigations to increase the worker acceptance and trust during collaboration. Deepened studies are compulsory in the healthcare sector, to investigate the social and ethical implications of HRC. Whatever the application context is, the implementation of more and more advanced technologies is fundamental to overcome the current HRC safety concerns, designing low-risk HRC systems while ensuring the system productivity

Life cycle analysis of innovative building materials based on circular coffee ground supply chain

The construction sector is widely recognized as one of the most polluting mainly due to its intensive exploitation of natural resources and large energy consumption to produce traditional building materials. In the last years, alternative building materials have been developed with the aim to reduce the environmental burden of this sector. In particular, the use of geopolymer mortars as alternative cementitious materials is gaining increasing acceptance among scientists. Numerous laboratory studies demonstrate their suitability for construction applications, highlighting the potential environmental benefits that can be obtained from their large-scale production. This study aims to perform a preliminary evaluation of the environmental performance of a geopolymer mortar, whose production includes the reuse of a food waste: Spent Coffee Ground (SCG). By using the Life Cycle Assessment (LCA) approach, an environmental comparison with a traditional production of cement mortar was carried out on the basis of the Global Warming Potential (GWP) indicator

Sustainable vehicle routing based on firefly algorithm and TOPSIS methodology

In a sustainable management of logistics, transportation plays a crucial role. Traditionally, the main purpose was to solve the Vehicle Routing Problem minimizing the cost associated with the travelled distances. Nowadays, the economic profit cannot be the only driver for achieving sustainability and environmental issues have to be also considered. In this paper, to satisfy the intricate limits involved in real vehicle routing problem, the study has been structured considering different types of vehicles in terms of maximum capacity, velocity and emissions, asymmetric paths, vehicle-client constraints and delivery time windows. The firefly algorithm has been implemented to solve the vehicle routing problem and the TOPSIS technique has been applied to integrate economic and environmental factors. Finally, to prove the effectiveness of the proposed approach, a numerical example has been proposed using data provided by a logistic company located in Sicily

Firefly algorithm based upon slicing structure encoding for unequal facility layout problem

Finding the locations of departments or machines in a workspace is classified as a Facility Layout Problem. Good placement of departments has a relevant influence on manufacturing costs, work in process, lead times and production efficiency. This paper analyses the problem of allocating departments with restrictions in terms of unequal area and rectangular shape within a facility, in order to minimize the sum of material handling costs taking into account the satisfaction of the aspect ratio requested. In particular, we propose for the first time a Firefly Algorithm based on the slicing structure encoding. The proposed method was tested comparing the results obtained from other authors on the same literature instance. The results confirm the effectiveness of the Firefly Algorithm in solving the Facility Layout Problem by generating the best solutions with respect to those provided by previous researches

ELECTRE TRI-based approach for sorting projects portfolio: Focus on the European strategy

The European Framework Programme for Research and Innovation aims to facilitate the collaboration between public and private sectors in delivering innovation. To achieve this goal, Union Research and Innovation Programme provides various financial instruments, among which the Horizon 2020 is one of the most significant. Since its implementation, the Horizon 2020 has stimulated the interest of several research organizations making the partnerships among companies their core business for improving local economy. In this context, technological districts are the main proponents of research and innovation spreading in the local territory. In Sicily, the AgroBioPesca district exploited these opportunities, undertaking the strategic “Call for ideas” proposal with the aim of building its own roadmap for research and innovation. To such an aim, AgroBioPesca collected several innovative project ideas coherent with some Technological Trajectories (TT) provided by Horizon 2020 and in line with the national and local operational programmes. These project ideas have been evaluated by a technical and scientific committee, taking into account specific criteria related to the Horizon 2020 technical guidelines. This paper aims to select the AgroBioPesca best projects portfolio by applying the multiple criteria sorting method (MCSM) ELECTRE TRI. A sensitivity analysis has lastly been conducted in order to verify the robustness of the solutions obtained

A model for predicting the mixed-mode fatigue crack growth in a bonded joint

Bonded joints are highly sensitive to the presence of defects and to the degradation phenomena, and this aspect represents the primary obstacle to their use in different structural engineering applications. Delamination in a bonded joint represents, in fact, one of the primary, most common and insidious causes of damage. In this paper, a numerical–experimental study on the crack propagation along the adhesive layer of a bonded joint specimen is carried out. Experimental study is focused on the evaluation of the damage modalities of a bonded joint when the specimens are subject to fatigue load. Experimental tests are compared with the results of several numerical analysis performed in ANSYS environment. A crack growth model is implemented in the finite element method solver and allows the simulation of the progressive delamination process. Comparison between numerical results and experimental tests allows to identify the descriptive numerical parameters of fatigue crack propagation, which may be used in the structures design