Wind analysis of the Messina Strait Bridge design project proposal with stabilizing cables

A new study on suspension bridges has been prompted by the big disaster of the Tacoma Narrow Bridge at half its design speed. The aerodynamic instability of long-span bridges has been studied using wind tunnel tests. As a result of improved aerodynamic performance from the geometrical configuration of the bridge deck, the aerodynamic criteria for suspension and cable-stayed bridges have become well established in recent years, thereby allowing longer bridge spans to be developed. Although the Messina Strait Bridge has yet to be constructed, we are looking forward to evaluating the impact of different deck cross-sections on both aerodynamic stability and cost reduction. To further improve the aerodynamic characteristics of long-span suspension bridges, an optimized multi-box bridge deck model with two side decks for traffic lanes, two middle railway decks, and three gaps separating them has been proposed aerodynamic performance has been experimentally verified. 1:80 scale wind tunnel tests have been conducted. According to the current MIDAS Model, the first torsional and the first vertical frequency ratios are 1.27787 and 1.36[1] respectively. It is the torsional/vertical frequency ratio, combined with the deck aerodynamic properties, that determines the wind response properties of the bridge for the most dangerous possible form of aeroelastic instability. The classic flutter is caused by the coupling of torsional and vertical modes. Stabilizing cables to the deck could be a solution to this classic flutter by reducing lateral displacement of the deck and increasing frequency ratios. Stabilizing cables will be installed on the deck in three different orientations: vertical, inclined, and horizontal, with diameters of 80 cm, 60 cm, and 40 cm in each orientation respectively. An overview of the research undertaken on this topic will be presented, as well as the most important findings.

Design of compliant mechanisms and their application to morphing wing technology

This thesis describes a study conducted for the development of a new approach for the design of compliant mechanisms. Currently compliant mechanisms are based on a 2.5D design method. The applications for which compliant mechanisms can be used this way, is limited. The proposed research suggests to use a 3D approach for the design of CM’s, to better exploit its useful properties. To test the viability of this method, a practical application was chosen. The selected application is related to morphing wings. During this project a working prototype of a variable sweep and variable AoA system was designed and made for an SUAV. A compliant hinge allows the system to achieve two DOF. This hinge has been designed using the proposed 3D design approach. To validate the capabilities of the design, two methods were used. One of these methods was by simulation. By using analysis software, a basic idea could be provided of the stress and deformation of the designed mechanism. The second validation was done by means of AM. Using FDM and material jetting technologies, several prototypes were manufactured. The result of the first model showed that the DOF could be achieved. Models manufactured using material jetting technology, proved that the designed model could provide the desired motion and exploit the positive characteristics of CM. The system could be manufactured successfully in one part. Being able to produce the system in one part makes the need for an extensive assembly process redundant. This improves its structural quality. The materials chosen for the prototypes were PLA, VeroGray and Rigur. The material properties were suboptimal for its final purpose, but successful results were obtained. The prototypes proved tough and were able to provide the desired motion. This proves that the proposed design method can be a useful tool for the design of improved CM’s. Furthermore, the variable sweep & AoA system could be used to boost the flight performance of SUAV’s.

Reg-Io. Innovare il Toys Design attraverso l'inclusione e la diversità

Reg-Io è un creatore di storie tramite il quale il bambino può divertirsi ad inventare racconti senza preoccuparsi della loro struttura narrativa. Il gioco invita il bambino a sperimentare le possibili relazioni tra le componenti così da poter trovare un modo per esprimere sé stessi e le proprie emozioni. Nella dinamica stessa del gioco non ci sono errori o scelte sbagliate, rendendo l'esperienza ludica totalmente libera e personale. L’obiettivo di Reg-Io è quello di abbattere l’insorgere di preconcetti e stereotipi sociali, che andrebbero radicandosi nel corso del tempo, tramite il gioco.

LQG control policy design against agent identity privacy problem

This thesis project studies the agent identity privacy problem in the scalar linear quadratic Gaussian (LQG) control system. For the agent identity privacy problem in the LQG control, privacy models and privacy measures have to be established first. It depends on a trajectory of correlated data rather than a single observation. I propose here privacy models and the corresponding privacy measures by taking into account the two characteristics. The agent identity is a binary hypothesis: Agent A or Agent B. An eavesdropper is assumed to make a hypothesis testing on the agent identity based on the intercepted environment state sequence. The privacy risk is measured by the Kullback-Leibler divergence between the probability distributions of state sequences under two hypotheses. By taking into account both the accumulative control reward and privacy risk, an optimization problem of the policy of Agent B is formulated. The optimal deterministic privacy-preserving LQG policy of Agent B is a linear mapping. A sufficient condition is given to guarantee that the optimal deterministic privacy-preserving policy is time-invariant in the asymptotic regime. An independent Gaussian random variable cannot improve the performance of Agent B. The numerical experiments justify the theoretic results and illustrate the reward-privacy trade-off. Based on the privacy model and the LQG control model, I have formulated the mathematical problems for the agent identity privacy problem in LQG. The formulated problems address the two design objectives: to maximize the control reward and to minimize the privacy risk. I have conducted theoretic analysis on the LQG control policy in the agent identity privacy problem and the trade-off between the control reward and the privacy risk.Finally, the theoretic results are justified by numerical experiments. From the numerical results, I expected to have some interesting observations and insights, which are explained in the last chapter.

Recupero e riutilizzo di uno scarpone da sci a fine vita. Ottimizzazione del processo di Design for Recycling con simulazione agli elementi finiti validata tramite correlazione di immagini digitale

Il presente elaborato di tesi è parte di un ampio progetto finalizzato alla realizzazione di uno scarpone da sci ottenuto per il 90% di materiale da riciclo di scarponi da sci a fine vita. L’obiettivo è di realizzare la progettazione del nuovo scarpone, e caratterizzarne le proprietà flessionali avvalendosi ti tecniche di simulazione numerica FEM validata attraverso Correlazione di Immagini Digitale. La caratterizzazione flessionale è realizzata con la prova del Flex Test, che consiste nell’imporre una flessione dorsale ad una protesi di gamba. Le prime simulazioni FEM di questo complesso modello hanno evidenziato delle criticità. La presente ricerca, si pone l’obiettivo di risolvere singolarmente questi problemi. Inizialmente, si è realizzata la blend polimerica dei materiali dello scafo e del gambetto dello scarpone. Si è effettuata la caratterizzazione meccanica del materiale, confrontandolo con il materiale vergine. Si è poi ricercato il modello costitutivo più adeguato di materiale iperelastico per il FEM. Successivamente, si è ottenuto il modello CAD della scarpetta attraverso l’approccio reverse engineering, con la tecnica della scansione 3D, la quale ha consentito di ottenere il file. STEP da aggiungere al modello FEM. La conoscenza della geometria effettiva ha consentito di realizzare il design della nuova scarpetta ottenuta da materiale riciclato. Infine, si è utilizzata la Correlazione di Immagini Digitali per studiare la cinematica della chiusura dei ganci dello scafo, e per studiare lo stato di deformazione residua a chiusura effettuata. Si è valutata l’influenza del piede della protesi, e della scarpetta, durante la chiusura dei ganci. In seguito, si è confrontato quanto ottenuto dalle evidenze sperimentali della DIC, con la simulazione agli elementi finiti. Si tratta di un approccio innovativo, che vede per la prima volta implementata la Correlazione di Immagini Digitali per realizzare la caratterizzazione meccanica di uno scarpone da sci.

Design for uncertainty of aerospace structures

The aim of this work is to present a general overview of state-of-the-art related to design for uncertainty with a focus on aerospace structures. In particular, a simulation on a FCCZ lattice cell and on the profile shape of a nozzle will be performed. Optimization under uncertainty is characterized by the need to make decisions without complete knowledge of the problem data. When dealing with a complex problem, non-linearity, or optimization, two main issues are raised: the uncertainty of the feasibility of the solution and the uncertainty of the objective value of the function. In the first part, the Design Of Experiments (DOE) methodologies, Uncertainty Quantification (UQ), and then Uncertainty optimization will be deepened. The second part will show an application of the previous theories on through a commercial software. Nowadays multiobjective optimization on high non-linear problem can be a powerful tool to approach new concept solutions or to develop cutting-edge design. In this thesis an effective improvement have been reached on a rocket nozzle. Future work could include the introduction of multi scale modelling, multiphysics approach and every strategy useful to simulate as much possible real operative condition of the studied design.

Upper-Limb Exoskeleton Design for Firefighter

Every day, firefighters are involved in emergency response tasks, which are both physically and psychologically exhausting. According to the National Fire Protection Association (NFPA), the number of firefighters who are injured or die while performing their job is incredibly high. When firefighters are injured, they must follow a rehabilitation therapy program to physically recover and depending on the severity of their injuries they may not fully recuperate at all. If they sustain a permanent injury that they cannot recover from, they may be out of work for the rest of their career. This research focuses on studying and developing a special device, known as an exoskeleton, aimed at assisting and preventing potential injuries among firefighters. Nowadays, the usage of human exoskeletons is becoming more common in a variety of fields. In fact, it is currently being researched and developed for soldiers, athletes, and critical care patients around the world. Most of the existing exoskeletons have been developed for the assistance of the lower human body. The research that I have done in my thesis instead relates to mobility of the upper body. Many of the existing exoskeletons have been analyzed and compared to each other and the human body, such as the study of human arm parts and their movements around three principal joints: shoulder, elbow, and wrist. The correct design of the shoulder exoskeleton join is still a big challenge for designers because of the complexity of biomechanical human movements. The exoskeleton must fit perfectly to the human body, otherwise it could be harmful for both the recovery and the safety of the user. The goal of this thesis is to design an upper-body arm exoskeleton worn by firefighters and develop and test a PID control system to prevent the risk of injuries while performing their job.

AIRYE: Uno strumento in realtà aumentata per la produzione musicale

L’elaborato di tesi che segue si propone di ricercare una nuova linea di esperienza utente e d’interazione attraverso la tecnologia della realtà aumentata contestualizzata nel mondo della produzione musicale. La tesi analizza innanzitutto la tecnologia come strumento d’interazione, la sua storia e la sua evoluzione fino ai nostri giorni con un excursus sui campi applicativi e i device utili per avere un’esperienza completa. L’analisi prosegue attraverso un’attenta ricerca sullo stato dell’arte e sulle applicazioni di realtà aumentata nel campo della musica presenti sul mercato per giungere ad una dettagliata indagine sugli strumenti che hanno indirizzato il concept di progetto. L’output di progetto è rappresentato da un’interfaccia 2d per la parametrizzazione di alcuni settaggi fondamentali ed infine da un’interfaccia semplificata in realtà aumentata. Quest’ultima è composta prevalentemente da sliders con cui è possibile modificare dei parametri della traccia audio portando l’esperienza di produzione musicale verso una concezione democratica, semplificata e giocosa. L’obiettivo di progetto è stato quello di creare un sistema di facile utilizzo anche da parti di utenti poco esperti con i software Daw presenti sul mercato attualmente.

Computational design of a new type of sandwich cross-section for a defined solution of a tree-like column produced by wire-and-arc additive manufacturing

When it comes to designing a structure, architects and engineers want to join forces in order to create and build the most beautiful and efficient building. From finding new shapes and forms to optimizing the stability and the resistance, there is a constant link to be made between both professions. In architecture, there has always been a particular interest in creating new shapes and types of a structure inspired by many different fields, one of them being nature itself. In engineering, the selection of optimum has always dictated the way of thinking and designing structures. This mindset led through studies to the current best practices in construction. However, both disciplines were limited by the traditional manufacturing constraints at a certain point. Over the last decades, much progress was made from a technological point of view, allowing to go beyond today's manufacturing constraints. With the emergence of Wire-and-Arc Additive Manufacturing (WAAM) combined with Algorithmic-Aided Design (AAD), architects and engineers are offered new opportunities to merge architectural beauty and structural efficiency. Both technologies allow for exploring and building unusual and complex structural shapes in addition to a reduction of costs and environmental impacts. Through this study, the author wants to make use of previously mentioned technologies and assess their potential, first to design an aesthetically appreciated tree-like column with the idea of secondly proposing a new type of standardized and optimized sandwich cross-section to the construction industry. Parametric algorithms to model the dendriform column and the new sandwich cross-section are developed and presented in detail. A catalog draft of the latter and methods to establish it are then proposed and discussed. Finally, the buckling behavior of this latter is assessed considering standard steel and WAAM material properties.

GUI design for in-car message diagnosis

Electronics needs communication to serve the vehicular world, to let all ECUs to com- municate with each other are needed buses, each bus serves different stuffs and is able to communicate. In the evolution of automotive architecture, integration of multiple func- tionalities in a single ECU will be one of the key aspects. The analysis of in-vehicle data, both for diagnosis and study-case of a particular behaviour, is the basis for future’s technologies and applications. Starting from these ideas, the need of creating a correlation between the Vehicle state and the anomaly. In order to create a link among them, has been created an interface able to simplify the in-car diagnosis and creating a link among vehicle stateand anomaly, looking also to the study-case of the driver's behaviour.

Fighting child marriage in developing countries: design and development of a mobile application

Child marriage is still a great issue in developing countries and even if the interventions to prevent it are having results, they are not enough to eliminate the problem. Among the strategies that seem to work most to fight child marriage, there is the empowerment of girls with information combined with education of parents and community. As smartphones are more accessible year after year in developing countries, this thesis wants to investigate if a mobile app could be effective in fighting child marriage and which characteristics such an app should have. The research was organized in four phases and used design and creation and case study methodologies. Firstly, the literature was analyzed and an initial design was proposed. Secondly, expert interviews were performed to gain feedback on the proposed design, and afterwards prototype was built. Thirdly, a case study in the Democratic Republic of Congo (DRC) was performed to test the prototype, gaining insights and improvements through group interviews with 26 girls aged 15-19. Finally, a first version of the app was developed and a second phase of the case study was run in the DRC to understand if the girls were able to use the app. This phase included 14 girls of which 6 had participated in the prototype testing and used questionnaires as a data generation method. The app was built following the Principles for Digital Development. Even if this app is built based on the case study in DRC is modular and easily adaptable to other contexts as it is not content-specific. It was shown that is worth continuing to study this topic and it was defined a conceptual framework for designing learning apps for developing countries, in particular, to fight child, early, and forced marriage.

Progetto LetsBox!: definizione del ciclo di vita del prodotto, design, sviluppo e validazione dell’UX

Questo volume di tesi ha l'obiettivo di descrivere l'intero processo di progettazione, sviluppo e rilascio di un'applicazione mobile, coinvolgendo anche gli end-user nella fase finale di valutazione. In particolare, il volume di tesi si sviluppa su quattro capitoli che descrivono 1) l'analisi dei requisiti, seguendo un approccio AGILE, 2) l'analisi del ciclo di vita del prodotto (inclusi business model e business plan), 3) l'architettura del sistema, e, infine, 4) la valutazione dell’usabilità e della UX. L'applicazione usata come caso di studio è "LetsBox!", un'applicazione mobile della categoria puzzle game, sviluppata sfruttando il framework di sviluppo di app ibride IONIC 5, con l’obiettivo di creare un gioco che coinvolgesse il giocatore tanto da farlo giocare nei suoi momenti di svago e indurlo a sfidare i record esistenti ma, nello stesso tempo creare un gioco originale e non esistente sul mercato.

"Assisted factorial experimental design" per l'ottimizzazione della determinazione di benzene ematico in gc-fid

La quantificazione del benzene ematico è un tema di grande interesse nell'ambito della tossicologia occupazionale. La determinazione dell'analita, estratto nello spazio di testa di un vial, è eseguita mediante l'utilizzo di un gascromatografo con rilevatore a ionizzazione di fiamma (GC-FID). Si è cercato di ottimizzare il processo di estrazione del benzene dal sangue allo spazio di testa ed il successivo trasferimento dell'analita nella colonna cromatografica, mediante l'applicazione di un disegno sperimentale fattoriale a tre fattori e due livelli (DoE). I fattori individuati per impostare il piano sperimentale sono stati: variazione della temperatura di incubazione (A) del vial contenente il campione di sangue, pH del campione (B), modulato mediante aggiunta di una soluzione di H2SO4 e forza ionica (C), regolata mediante una soluzione acquosa di NaCl. I livelli scelti per ciascuna variabile sono stati: per A 40 e 60 °C; per B pH naturale del campione e pH a seguito dell'aggiunta di 1 mL di H2SO4 1.8 M; per C FI naturale del campione e FI dovuta all'aggiunta di una soluzione acquosa di sodio cloruro (5 g/L). Dall'analisi dei risultati forniti dal DoE, si è osservato che A, B e C hanno effetti tra loro contrastanti, per questo motivo non sembra essere vantaggioso combinare variabili differenti. In compenso, sia l'aumento di temperatura che l'aggiunta di acido solforico portano a significativi miglioramenti nell'estrazione di benzene dal sangue. Tra i tre trattamenti risulta essere B quello più efficace, motivo per il quale si ritiene che l'aggiunta di una soluzione acquosa di H2SO4 al campione di sangue porti ad una maggiore sensibilità e risoluzione strumentale. Sicuramente la sensibilità del metodo elaborato non può essere paragonata alle tradizionali determinazioni con spettrometro di massa, ma si ritiene possa essere sufficientemente soddisfacente per valutare l'esposizione a benzene dei lavoratori a rischio e come analisi di screening rapida ed economica.

Virtual commissioning of automatic machines for mesh panels manufacturing

The purpose of this thesis is to present the concept of simulation for automatic machines and how it might be used to test and debug software implemented for an automatic machine. The simulation is used to detect errors and allow corrections of the code before the machine has been built. Simulation permits testing different solutions and improving the software to get an optimized one. Additionally, simulation can be used to keep track of a machine after the installation in order to improve the production process during the machine’s life cycle. The central argument of this project is discussing the advantage of using virtual commissioning to test the implemented software in a virtual environment. Such an environment is getting benefit in avoiding potential damages as well as reduction of time to have the machine ready to work. Also, the use of virtual commissioning allows testing different solutions without high losses of time and money. Subsequently, an optimized solution could be found after testing different proposed solutions. The software implemented is based on the Object-Oriented Programming paradigm which implies different features such as encapsulation, modularity, and reusability of the code. Therefore, this way of programming helps to get simplified code that is easier to be understood and debugged as well as its high efficiency. Finally, different communication protocols are implemented in order to allow communication between the real plant and the simulation model. By the outcome that this communication provides, we might be able to gather all the necessary data for the simulation and the analysis, in real-time, of the production process in a way to improve it during the machine life cycle.

Enhanced switchgear connection testing through augmented reality: early developments

Augmented reality is an emerging field of interactive design in which virtual material is seamlessly blended with displays of real world environments. The tremendous potential of augmented reality has begun to be explored with the emergence of personal mobile devices capable of constructing engaging augmented reality experiences. This work is part of a project aiming at using augmented reality goggles to bring advance information to the user interacting with switch-gear during automation cabling. In particular we will be focusing on the recognition and definition of the figures of the component on the AR device. In this part we are using standard camera that allows us to get real images and helps us to localize the gearbox in space through ARUCO marker and we can exploit in order to re-project the actual shape of the component that are currently interested in manipulation by exploiting the data provided by the database. The experiments are carried out using the camera to get the images of the real world switch-gear and re-project those images with the component superimposed on it. Using transforms of the database we did localization to re-project the rendered image of component exactly on the real world component, which can be further integrated in AR goggles to see the component superimposed in real-time.