https://repositorio.ufu.br/handle/123456789/5146 2026-10-11T16:47:13Z https://repositorio.ufu.br/handle/123456789/50554 Title: Desenvolvimento e caracterização de sistema de eletrodeposição por jato para manufatura aditiva eletroquímica: investigação experimental dos efeitos de parâmetros de processo na qualidade de depósitos de cobre Abstract: Electrochemical Additive Manufacturing (ECAM) is an emerging technology with the potential to revolutionize the microfabrication of metallic components. This thesis focuses on the development and characterization of a jet electrochemical deposition (Jet-ECD) system for copper ECAM, investigating the effects of process parameters on deposit quality. The main objective was to model the influence of nozzle feed rate, current density, inter-electrode distance, and electrolyte flow rate, as well as solution composition, on the deposition rate, morphology, microstructure, and mechanical properties of copper deposits. The research developed a robust and automated Jet-ECD system, enabling systematic process investigation. The methodology involved multiscale characterization of deposits through laser interferometry, scanning electron microscopy (SEM), and Vickers microhardness testing. The results established quantitative correlations between process parameters and deposit characteristics, revealing that electric current is the dominant parameter with nonlinear behavior. Feed rate and electrolyte composition also showed significant influences on morphology and process stability. The experimental results demonstrated a wide variability in the properties of copper deposits as a function of the investigated process parameters. The arithmetic mean deviation of the assessed roughness profile (Ra) ranged from 0.6 μm to 2.0 μm, demonstrating greater sensitivity to variations in electric current. The arithmetic mean deviation of the assessed waviness profile (Wa) ranged from 1.1 μm to 4.3 μm, evidencing sensitivity to the hydrodynamic parameters of the process. The deposition rate fluctuated between 0.008 mg/min and 0.068 mg/min, with maximum values obtained under the highest electric current analyzed (6 mA) and the highest feed rate analyzed (1.4 mm/min). The grain size of the polycrystalline deposits varied from 0.8 μm to 1.2 μm, indicating a relatively fine microstructure controllable by the electrodeposition parameters. The Vickers microhardness showed significant variation, ranging from 100 HV to 170 HV, with maximum values of 170 HV obtained under 4 mA current and 0.6 mm/min feed rate, demonstrating the ability to tailor mechanical properties through process parameter control. It was concluded that the study provides relevant technological, scientific, and methodological contributions to the consolidation of Jet-ECD as an advanced manufacturing technology, demonstrating its capability to produce materials with controllable properties. 2025-09-26T00:00:00Z https://repositorio.ufu.br/handle/123456789/50538 Title: Memorial Descritivo 2026-10-02T00:00:00Z https://repositorio.ufu.br/handle/123456789/50520 Title: Desenvolvimento de uma Nova Estrutura Robótica para Reabilitação Bimanual Acoplada a Jogos Sérios Abstract: Upper-limb functional impairments caused by stroke, neurological disorders, and other motor dysfunctions significantly affect patients' independence, making rehabilitation an essential process for functional recovery. In this context, robotic rehabilitation has emerged as an effective alternative for providing repetitive, controlled, and safe therapeutic exercises while enabling continuous monitoring of patient progress. This dissertation presents the development of a novel robotic structure for upper-limb bimanual rehabilitation, consisting of a planar five-bar mechanism coupled with a third degree of freedom responsible for the movement of the contralateral limb. Initially, the robot workspace was designed based on anthropometric data, followed by the development of direct and inverse kinematic models implemented computationally to control the end-effector position. Subsequently, the mechanism dimensions were optimized to reduce the bar lengths while preserving the required workspace. Based on the optimized geometry, a static analysis using the Jacobian matrix was performed to determine the actuator torques throughout representative configurations of the workspace, providing support for motor selection. The mechanical structure was designed using CAD software and validated through computational analyses, resulting in the construction of a functional prototype integrated with an Arduino-based control system and a Unity application. The developed interface enables real-time robot monitoring and the execution of four serious games designed to promote motor training and increase user engagement during rehabilitation exercises. The results obtained demonstrated the mechanical and computational feasibility of the proposed robotic structure, as well as the effectiveness of integrating the kinematic models, embedded control system, and graphical interface. Therefore, the proposed system represents a low-cost platform for assisted upper-limb rehabilitation and provides a solid foundation for future studies involving advanced control strategies, patient adaptation, and clinical validation. 2026-08-28T00:00:00Z https://repositorio.ufu.br/handle/123456789/50457 Title: Comparative study of aerodynamic models for aeroelastic flutter prediction and dynamic stall Abstract: The present work reviews and compares the main methods for modeling bidimensional aeroelastic flutter, with particular focus on different aerodynamic formulations and their ability to represent dynamic stall effects. The objective is to provide a comparative view of these methods, serving as an auxiliary set of tools for estimating and predicting experimental results, especially in the context of research aeroelastic tests. Simpler attached-flow formulations, namely quasi-steady and unsteady models, are first investi gated, followed by more advanced semi-empirical dynamic stall models, namely the ONERA and Leishman–Beddoes formulations. All models are numerically implemented in MATLAB and analysed through comparison with a reference experimental case from the literature. By identifying the main characteristics, advantages, and limitations of each approach, it is concluded that, among the attached-flow methods, the unsteady Wagner aerodynamic model provides more accurate predictions than the quasi-steady formulation, since flutter is inherently a high-frequency dynamic phenomenon. Among the semi-empirical models with dynamic stall representation, the Leishman–Beddoes method yields the most satisfactory results, mainly due to the previously validated calibration of its aerodynamic parameters. 2026-03-24T00:00:00Z