Programa de Pós-Graduação em Engenharia Industrial - PPGEI/ITEC
URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/10050
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Navegando Programa de Pós-Graduação em Engenharia Industrial - PPGEI/ITEC por Linha de Pesquisa "MATERIAIS E PROCESSOS DE FABRICAÇÃO"
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Item Acesso aberto (Open Access) Análise do estado plano de tensões em chapas de aço ASTM A131 por métodos ultrassônicos(Universidade Federal do Pará, 2023-08-17) ALBUQUERQUE, Lucas Gabriel de Sousa; MACHADO, Paulo Cordeiro; http://lattes.cnpq.br/0133330144786049; https://orcid.org/0000-0003-4375-6812Residual stresses affect the mechanical component in the same way that external stresses do. These stresses usually arise in the manufacturing process. By knowing the residual stresses, mainly the tensile stresses, present in a component or those that may be generated by some manufacturing process, it is possible to take actions to avoid or minimize their effects, thus extending the component's useful life. Thus, residual stress will always be a demand to be studied, both by academia and by the metal-mechanic industry. Therefore, the objective of this work was to determine the plane state of residual stresses in ASTM A131 steel plates by combined shear and compressive ultrasonic wave methods. A TIG welding torch was used to induce residual stresses in the plates by the high thermal gradient. The specimens were xed by supports to avoid deformation, thus preserving the residual stresses. Three different methods were applied, named, in this paper, as: Hirao I; Clark; and Hirao II. The major difference between them is related to the preferred direction of wave propagation. Stresses in different directions from the anisotropy axis can change this direction. Consequently, the angle between the anisotropy and the preferential direction of propagation of the ultrasonic wave (φ) is changed. To measure the propagation time of the ultrasonic waves, a software was developed for the acquisition of the ultrasonic response signals and another one for the data processing.To end the preferential angle of wave propagation, a support was made by 3D printing, which allowed the transducer to be moved using a stepper motor. In all three methods, very high tensile stresses were observed near the melt zone, which decreased rapidly as the distance from this region increased. In addition, the values of φ were lower in the center line than in the lateral lines, indicating variation in residual stress levels as function of distance from the constraints.Item Acesso aberto (Open Access) Caracterização mecânica e análise fractográfica de compósitos poliméricos com fibras naturais do epicarpo do coco babaçu (Orbignya Speciosa)(Universidade Federal do Pará, 2022-12-14) SANTOS, Hudson Carlos Melo dos; GOMES, Laércio Gouvêa; http://lattes.cnpq.br/5907468972539239; https://orcid.org/0000-0002-8474-0748The pressure exerted on natural resources, arising from the exponential growth of world demand, leads human activity to an unprecedented scenario. Researchers have been demonstrating numerous efforts for sustainable solutions, in this scenario there is a continuous growth in the development of composite materials with vegetable fibers. In this work, pure orthophthalic polyester matrix materials and composite materials with plant fibers from the babassu coconut epicarp were produced. The composites were manufactured manually using silicone molds. The fibers characterized according to their morphology, through scanning electron microscopy (SEM), were randomly inserted with mass fractions set at 3% and 5%, length varying between 10 mm and 20 mm. The composites produced were analyzed for their mechanical properties, through tensile and flexural tests according to ASTM D 638 and ASTM D 790 standards, and fractographic analysis of the fracture surface through scanning electron microscopy (SEM). The morphological analysis of the surface of the fibers showed its roughness and characteristics present in vegetable fibers. For composites with 3% of fibers, a tensile strength of 20.03 MPa was obtained, while for composites with 5% of fibers, the result was 14.16 MPa. of 32.34 MPa for the composites with 3% of fibers and 37.01 MPa for the composites with 5% of fibers, in both properties (tensile strength and flexural strength) there was a reduction of the same when compared to the matrix material pure. With regard to the modulus of elasticity, the composites had an increase in this mechanical property when compared to the pure matrix, confirming that the increase in the stiffness of the material is due to the increase in the fiber fraction, with the best results obtained in composites with 5 % of fibers, 0.486 GPa in tensile tests and 27.10 GPa in bending tests. The fractographic analyzes of the fracture surfaces showed satisfactory results regarding the identification of failure mechanisms and characteristics present in the composites, such as the presence of air bubbles, voids and the phenomenon of fibers pulled out of the matrix (pull out), indicating low adhesion at the interface matrix/fiber.Item Acesso aberto (Open Access) Caracterização mecânica e metalúrgica de parafusos da classe 10.9, utilizados na fixação da suspensão dianteira de veículos CAT793D, aplicando tratamento termoquímico de cementação(Universidade Federal do Pará, 2022-08-31) RABELO JÚNIOR, Fábio Alves; CARDOSO FILHO, José Carlos de Araújo; QUARESMA, José Maria do Vale; http://lattes.cnpq.br/7443111804471290When a structural component of a large piece of equipment fails, catastrophic consequences can occur, generating highly measurable economic losses, because a failure leads to an interruption of an entire production line and damage to the workflow, which can cause delays and increased maintenance costs, whether preventive or corrective. In addition, serious risk conditions affect the loss of life in cases of catastrophic accidents, where they are widely reported by the media and strongly influence an organization's conduct. The objective of this work is to carry out the mechanical and metallurgical characterization of screws of class 10.9, applying the Thermochemical Treatment of Cementation, evaluating the influence of this mechanical resistance. These components include the Caterpillar model 793D “Off-Highway” truck suspension system that carries heavy iron ore loads in the Ferro-Carajás complex, in the state of Pará. Thermo-chemical treatments and mechanical tests were carried out and Tensile Stress. Fractographic and Microstructural analyzes were performed using Scanning Electron Microscopy - SEM, in addition to Optical Microscopy.Item Acesso aberto (Open Access) Desenvolvimento de monitoração na geração fotovoltaica em comunidades isoladas(Universidade Federal do Pará, 2023-04-26) GONÇALVES, Francisco Reginaldo Conceição; VIEIRA JÚNIOR, Petronio; http://lattes.cnpq.br/1958791286192330Nowadays, photovoltaic solar energy represents a significant portion of all electricity consumed in the world. It is crucial to develop tools for monitoring the solar system that aim to maintain generation productivity and mitigate security risks. This work presents a proposal for a development platform for monitoring photovoltaic generation for isolated communities, consisting of generation simulation, data transmission, database and supervisory system. The mathematical model used in the simulation is based on a system being implemented by the Automation Technology Group (GTA) at the Electrical Engineering Laboratory of the UFPA University Campus in Belém. Data are obtained by simulation and are transmitted to the cloud through a NodeMCU ESP8266 microcontroller. The computer, in addition to performing the simulation to obtain photovoltaic generation data, also accesses the clouds, acquiring data for the supervisory. The supervisory system is developed on the Internet of Things (IoT) platforms Thingspeak and Cloud Database, allowing the detection and diagnosis of failures. Measures such as solar radiation intensity, temperature, humidity, electric voltage and electric current are analyzed in order to diagnose faults. Through cloud computing, data is stored and made available in real time, with ample capacity and mobility, allowing remote monitoring of the system. Database tools with dedicated interfaces are used, as well as platforms focused on the internet of things. The photovoltaic generation is being implemented in an experimental bench, and the parameters of the simulated model have the same amplitudes as the real model, which has 1 solar panel with a maximum power of 130W, a maximum voltage of 17.6V and a maximum current of 7.39A. The perspective of this work is to improve the supply of electricity to isolated communities through remote monitoring of the generation system, with social and economic impact.Item Acesso aberto (Open Access) Emulação de carga para geração de energia elétrica usando inversor(Universidade Federal do Pará, 2022-06-30) LOPES, Marcos Andrey da Silva; VIEIRA JÚNIOR, Petrônio; http://lattes.cnpq.br/1958791286192330This paper aims to emulate variable load on a simulation bench for wind and hydraulic generation using an inverter connected to a fixed load consisting of a bank of resistances and inductances. From the modeling performed on the hydraulic and wind turbines, it is possible to reproduce the effects caused by variations in the dynamics of each generation, such as the variation in wind, for wind, or the flow of water in a distributor, for hydraulic . The generation simulation bench is composed of a separate excitation machine (DC motor), simulating the primary source, driven by a converter, which is coupled to a generator, this one feeding the inverter, which is responsible for the interface with the load. From this coupling of the motor-generator set, it is possible, through the inverter, to carry out the load variation, in order to simulate different load conditions in the generation. The inverter is used as a load variation strategy for dynamic response studies of simulated generation systems, voltage and frequency regulation, harmonic analysis in the system, among many situations. Through this set, it was possible to vary the generator armature current by properly configuring the inverter parameters. To complete the study, the look at table method is proposed for the proper selection of inverter parameters for load variation.Item Acesso aberto (Open Access) Implantação da manutenção centrada na confiabilidade (MCC) em um alto forno de usina siderúrgica(Universidade Federal do Pará, 2023-07-05) BASTOS, Filipe Carneiro; FUJIYAMA, Roberto Tetsuo; http://lattes.cnpq.br/3165747089941318; https://orcid.org/0000-0002-2738-6666The technological development has provided many changes in the industrial process, and has led to the need for improvement of maintenance in view of the importance of operational availability for the companies' results. In this perspective, the Reliability Centered Maintenance has been widely used in the industrial sector, aiming improvements in the process and ensuring the reliability of the assets. To apply the method, the 5 steps for implementation were followed, in the following order: (i) Selection and training of a multidisciplinary team, (ii) Selection of the system/process and information collection, (iii) Reliability analysis of the critical equipments, (iv) Analysis of the functions and functional failures, (v) Application of FMEA (Failure Mode and Effects Analysis) and (vi) Determination of the new maintenance plans. Finally, a comparison was made between the maintenance plans before and after the MCC implementation and the gains obtained by reducing the number of corrective maintenances in a certain period of analysis were presented.Item Acesso aberto (Open Access) Influência da taxa de resfriamento nas tensões residuais de solda por centelhamento de trilho ferroviário(Universidade Federal do Pará, 2021-12-22) BARILE, Iury Klay Peres; COSTA, Ednelson da Silva; http://lattes.cnpq.br/0045584096510351; HTTPS://ORCID.ORG/0000-0002-7290-3810; MACHADO, Paulo Cordeiro; http://lattes.cnpq.br/0133330144786049; https://orcid.org/0000-0003-4375-6812The process of manufacturing and welding in rail induces residual stresses that can act in a deleterious way to the structural integrity of this component, especially in cases where the tractive stresses, can favor the nucleation and propagation of cracks, may cause premature rail failure. The objective this work is evaluate the residual stresses of rails welded by flash butt welding (FBW) with and without heat treatment post welding with forced air cooling. The techniques measurement of residual stress ultrasound using shear waves in the metal base and hole Drilling in the center of the weld and in the zone thermally affected (HAZ). The techniques presented similar results to those found in the literature, for the head, tensile stresses were found in the base metal region, and compressive stresses in the HAZ and center of the weld. In the web, tensile stresses were found at the HAZ and the center of the weld.Item Acesso aberto (Open Access) Projeto, montagem e testes de fonte Cockcroft - Walton para Electrospinning(Universidade Federal do Pará, 2022-06-06) ARAÚJO FILHO, Paulo Sérgio Alves de; VIEIRA JÚNIOR, Petrônio; http://lattes.cnpq.br/1958791286192330; DIAS, Carmen Gilda Barroso Tavares; http://lattes.cnpq.br/2113791118142177Electrospinning is a way of spinning using an electric field, the wire formed has a nanometric diameter and is used in biomaterials, pharmaceuticals, electronics, in the area of semiconductors and energy generation. During electrospinning, the solution leaves a starter vessel and reaches a screen through the force of the electric field. The method fits according to the purpose of the experiment. For each objective there are a variety of polymers, solvents, the latter defining the operating ranges for: field strength, voltage and operating distance. A source was designed and assembled using the Cockcroft multiplier. For the design of the circuit, design and simulations were carried out. For validation, electrospinning was performed using the source.Item Acesso aberto (Open Access) Remoção de Ni2+ de soluções aquosas utilizando o talo do cacho do açaí (Euterpe oleracea) como Biossorvente(Universidade Federal do Pará, 2021-06-30) GESTER, Nayara Matos Lima; SIQUEIRA, Joana Luíza Pires; http://lattes.cnpq.br/4650162959340860This work used as biosorbent the stem of the açaí bunch (Euterpe oleracea) – TCA – in natura for phytoremediation of the heavy metal Ni2+ from synthetic solutions. The material was characterized using Fourier Transform (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) techniques. The result of the infrared analysis revealed the presence of hydroxylic and carboxylic functional main groups fundamental in the biosorption process. The SEM analysis showed a material with a rough and porous structure with a visible variety of pore sizes and the EDS semi-quantitatively detected the presence of elements such as C, O and Ca, characteristic of lignocellulosic materials, in addition to the presence of Ni2+ after the process of adsorption. The adsorption behavior of Ni2+ ion in aqueous solution by the açaí bunch stem (ACT) was carried out in batch and investigated influences such as concentration, dosage, granulometry, contact time and pH. At a concentration of 25 mg.L-1 and pH between 6 and 7 TCA showed removal efficiency above 80%. Langmuir, Freundlich and Dubinin-Radushkevich models were applied to describe the equilibrium isotherms using linear regression analysis. The adsorption kinetic mechanism was better represented by the pseudo-second order kinetics. Monolayer adsorption according to the Langmuir model better described the biosorption process in TCA with a correlation coefficient (R2) close to 1 and a maximum adsorption capacity of 8.62 mg.g-1. The process kinetics showed a better fit to the pseudo-second order model, indicating chemisorption, with R2 close to 1, adsorption capacity (qe) = 6.60 mg.g-1 and adsorption rate constant (K2) = 0.082 g.mg-1.min-1. The TCA in natura presented satisfactory results for the treatment of wastewater, a fact that reinforces its environmental proposal.