Navegando por Orientadores "SOEIRO, Newton Sure"

Agora exibindo 1 - 8 de 8

Acesso aberto (Open Access)
Análise de esforços resultantes de impactos entre barcaças de comboios fluviais para modelagem de um sistema de amortecimento de choques utilizando teoria de análise multicorpos
(Universidade Federal do Pará, 2018-03-09) CRUZ, Fernando Costa da; SOEIRO, Newton Sure; http://lattes.cnpq.br/7303174583088137; https://orcid.org/0000-0003-4224-767X
In this dissertation an analysis is performed on the operational behavior of river barges convoys in navigation regions with presence of waves, winds and currents. A study is carried out to determine the applicant forces present in the mooring elements and in the contact points between barges in flotillas when they are sailing in dangerous navigation conditions. A theoretical study is carried out, identifying the main response movements of floating bodies. In this case, a model is developed using the ANSYS AQWA 17 software to identify the stress levels from impacts between barges that make up the formations, as well as the degree and behavior of the tensile stresses present in the mooring ropes over time. In addition, a practical study is used as a comparative model of data, being very important for the validation of the results achieved by the computational model. In this way, the proposed scenario within the computational program describes environmental characteristics to describe the navigation problem in a clear way. At the end of this work the levels of effort captured within the computational model are presented, being divided into two models of fluvial flotillas, a convoy with barges for soybean transportation, and another with barges for the transport of iron ore, being discriminated the locations of the higher levels of effort. It is important to note the pioneering role of this work in relation to the problems perceived within the area of operational safety of fluvial flotillas, using Finite Element tools as the main evaluation tool.
Acesso aberto (Open Access)
Controle de vibração em reatores elétricos através de absorvedores dinâmicos viscoelásticos
(Universidade Federal do Pará, 2006-04-18) VALE, Alan Rafael Menezes do; SOEIRO, Newton Sure; http://lattes.cnpq.br/7303174583088137
Equipments used in electric substations have specific functions in the functioning and maintenance of the functionality of such installations, being equipment applied to control reactive currents, short circuit currents and maneuver poles in transmission systems of electric energy. It was detected that some reactors in functioning had presented high levels of structural vibration. Two of these reactors operate in the substation of Rurópolis city, situated the west of Pará state. Another decurrent problem of the raised level of vibration of these structures is the generation of hot spots in the electromagnetic nucleus of the reactor, being able to generate bubbles of highly inflammable gases. The existence of these operational problems can cause to the North of Brazil Transmission System functional interruptions in the transmission of electric energy. That would cause in the North region and other linked ones (Northeast, Southeastern and Center-West) raised social and financial damages. The application of tools for reducing the vibrate-acoustic trouble (reduction of the levels vibration and, therefore, noise) can prevent structural and operational damages that result in its operative non-availability reducing, consequently, losses and the necessity of the development of equipment of cost raised with low indices of vibration. In the intention of if reducing such levels, it is considered the application of dynamic absorbers in the external structure of the reactors. With the calculated absorbers in amount, position and parameters (mass, stiffness and damping) expects to create a system syntonized with the frequency of the excitement of electromagnetic nature, that will absorb part of the vibratory energy of the reactor, having minimized raised detected levels and, therefore, all the subsequent problems. Viscoelastic materials will be used in the dynamic absorbers (with temperature and frequency dependent dynamic properties), because these materials to increase the field of activity of the dynamic absorbers, adjusting themselves it the raised verified modal density in the metallic shells of the reactor.
Acesso aberto (Open Access)
Desenvolvimento de painéis confeccionados a partir de fibras de coco para controle acústico de recintos
(Universidade Federal do Pará, 2008-10-31) VIEIRA, Rodrigo José de Andrade; SOEIRO, Newton Sure; http://lattes.cnpq.br/7303174583088137
A reasonable alternative for noise control in enclosures is based on the use of sound absorption materials (porous and fibrous), which convert acoustic energy into heat, due to air viscosity. The material acoustic absorption characteristic is determined by its sound absorption coefficient, which depends mainly on frequency, sound incidence angle, density, thickness and internal structure of the material. From the Amazon, due to its enormous biodiversity, thousands of natural products and sub products are retrieved, some of which are not completely used. Thus, many residues reach other industrial sectors, such is the case of the coconut fiber, which can be used in many ways. Therefore, the present work defines and describes an acoustic panel manufacturing process, based on coconut fiber, including the experimental determination of important parameters for noise control in enclosures. Also, a numerical model is implemented to investigate cost and quality control parameters, in order to assist the development and manufacturing of new panels. First, the necessary information is collected to start the development process of coconut fiber panels, following an “informational project” methodology. Next, all the steps related to the panel manufacturing process are described, looking forward to obtaining its acoustical, mechanical and physical-chemical main properties. From the numerical simulations, one tries to analyze and predict the coconut fiber panel behavior (apart from a commercially available acoustical panel), and investigate its influence over the acoustical parameters of an auditorium (reverberation time, sound pressure decay, and intelligibility). With the development of the coconut fiber panels, one expects to contribute for the creation of new sectors on the local economy, mainly considering the elevated costs of the actual acoustical panels available in the market. Finally, another outstanding advantage of the coconut fiber panels proposed here is the possibility of its usage in the context of regional architecture, where emphasis is given on local materials.
Acesso aberto (Open Access)
Diagnóstico numérico em embarcações de atendimento de atendimento médico-hospitalar visando à otimização vibro-acústica
(Universidade Federal do Pará, 2017-11-10) FERREIRA, Aracelli Suzane Andrade; SOEIRO, Newton Sure; http://lattes.cnpq.br/7303174583088137; https://orcid.org/0000-0003-4224-767X
The use of vessels for hospital care has been one of the main means used by some prefectures belonging to the states of the Legal Amazon to take medical and dental care to communities located in distant locations. These vessels were named by the Ministry of Health of Basic Units of Fluvial Health (UBSF). The design of these units, however, is differentiated in many ways, since it provides for the installation of equipment not present in other conventional vessels. In addition, the service performed in these units requires satisfactory acoustic-vibro-conditions so that health professionals can perform the procedures correctly. This work aims to perform a numerical analysis through the Finite Element Method to evaluate the modal and acoustic properties of the medical service vessel. The work contemplated two analyzes: modal and acoustic. In the modal analysis, the axis, propeller and the structure of the UBSF were considered as objects of study, as these are the main sources of excitation. The acoustic analysis sought to ascertain the main sources of noise emission and its propagation within the UBSF. In this second analysis, it was possible to predict the overall sound pressure level and octave bands inside the vessel. The Ansys and Comsol softwares were used for the modal and acoustic analysis, respectively. After the analyzes, the data obtained with the main national and international standards related to the subject were compared. The results found in this study demonstrated that the reference model proposed by the Ministry of Health did not meet the criteria established by the norms. It is proposed, therefore, as solutions to attenuate the undesired effects from the acoustic-acoustic phenomena, the use of materials with absorptive properties and increase in the structural rigidity of the vessel. Such measures would allow users and crew members to improve the comfort and conditions of basic health care services.
Acesso aberto (Open Access)
Estudo de vibrações eólicas em linhas de transmissão de energia elétrica de alta tensão
(Universidade Federal do Pará, 2008-10-30) SANTOS, Alexandre Sá dos; SOEIRO, Newton Sure; http://lattes.cnpq.br/7303174583088137
The increasing demand for electrical energy has stimulated the technological advance of the equipment associated to its transport, generating a situation in which one has to operate under ever increasing nominal voltages, mainly due to economical reasons. This fact has a direct implication on the diameter of the conductors, elevating their cost, as well as that of the supporting structures. In order to overcome this problem, without cost elevation of the electrical transmission line project, the idea is to use more than one conductor per phase, in a parallel assembly with small distances between cables, which can be achieved through the insertion of spacers at regular intervals between the supporting towers. However, operational mechanical problems may arise such as, for example, total or partial rupture of cables and/or spacers due to dynamical wind excitations. Thus, this work investigates the dynamical behavior of a bundle of cables of electrical transmission lines, using a finite element model, which reproduces the coupling between cables and the transmission lines’ spacers-dampers and the fixing structures, considering non-linear geometrical effects due to huge cable displacements, and line continuity, i.e., the adjacent vain, which is taken into account by the model as an equivalent stiffness. Wind load is modeled through a non-deterministic process, from its statistical properties, such that two parts are considered: an average load, statistically analyzed, and a variable load, analyzed as a transient. Results show that the variable load part conduces to a dynamic response of the model, which could represent a dominant behavior. Therefore, the traditional methodology of assuming wind load as a static excitation could lead, in some cases, to disastrous consequences.
Acesso aberto (Open Access)
Implementação e análise do desempenho de técnicas de monitoramento através de medição de vibração e correlação com corrente estatórica
(Universidade Federal do Pará, 2010-06-16) JESUS, Keliene Maria Sousa de; SOEIRO, Newton Sure; http://lattes.cnpq.br/7303174583088137
The growing demand for electricity coupled with the great importance of this sector to the national economic system has led the government and private companies to invest in studies for improving the performance of the systems involved in this process, given the important gains that this initiative can produce. In this context, this work is a contribution to the study of the development of a methodology for diagnosis of defects to the machine number three hydro Hydropower Plant Coaracy Nunes, located in Amapa State. In many situations the methods of vibration analysis is used to detect the presence of faults in this type of machine, this work will also be used to analyze the current signals to provide similar indications. This work aims to present a methodology for fault diagnosis in electrical machines using the vibration signals and correlation with the analysis of the stator current. Throughout this work presents a review of techniques for monitoring and diagnosis of the condition of electrical machinery, through vibration tests correlated with the characteristics of the stator current. The result of the correlation of vibration measurement with the current measurement is based on a methodology implemented by a system of acquisition and data processing platform developed in LabView. The experimental results were obtained from mechanical defects (unbalance and mechanical defects on the slopes, and internal bearings) induced in an experimental device designed with the intention to represent a generation system. Finally, the vibration and current signals were analyzed and compared to verify that the defects that were detected by the conventional vibration altered the behavior of current signals. The good results of this study demonstrate the feasibility of future studies in this area.
Acesso aberto (Open Access)
Projeto e construção de câmaras reverberantes em escala reduzida para o estudo das características de perda de transmissão de divisórias confeccionadas a partir de materiais regionais
(Universidade Federal do Pará, 2006-09-05) TOUTONGE, José de Aviz; SOEIRO, Newton Sure; http://lattes.cnpq.br/7303174583088137
To project and build reverberant chambers, in scaled model, for the determination of materials transmission loss used for noise control purposes was the objective of this research. Besides, the research seeks to establish a methodology of analysis and interpretation of the acoustic parameters starting from the theory of scaled models, in such way that one can infer the transmission loss of the studied materials. The necessity of this construction occurs due to the non availability of real scale reverberant chambers (only available in some regions of Brazil), making it difficult and raising the costs of material performance tests in other Brazilian regions. Therefore, reverberant chambers were constructed in a reduced scale of 1:6, in order to allow the transmission loss study of party walls, developed with regional materials, confronting their performances and, simultaneously, their use in academic activities. Despite the fact of the chambers have been constructed in reduced scale, the scale factor (1:6) was not considered, meaning that measurements had been carried through in the real octave bands between 125 Hz and 8 kHz. Party walls had been assayed for the determination of the acoustic parameters, based on ISO 140 and 354. Finally, from experimental results, it was possible to prove the efficiency of materials used in the construction of partitions, which could be used for noise isolation purposes in buildings and industrial enclosures. Apart from the experimental assays, analytical calculations had been fulfilled according to the formulation of Analysis Energy Statistics (SEA) in order to provide evidence and validation of the results.
Acesso aberto (Open Access)
Projeto e construção de uma câmara reverberante em escala reduzida para a caracterização acústica de materiais absorventes
(Universidade Federal do Pará, 2007-05-31) GUEDES, Reginaldo Cascaes; SOEIRO, Newton Sure; http://lattes.cnpq.br/7303174583088137
In the area of Acoustics, concerning the last decades, a significant growth has been observed in the demand for data regarding not only the absorbing characteristics of acoustical materials, but also the usage of numerical methods which are able to represent the acoustical behavior of real systems. These real systems demand a significant infrastructure, which means a great deal of investments. Thus, in order to attend such demands for new data, to allow the development of research regarding the sound absorbing characteristics of regional materials and to develop practical classes on acoustics, both for graduate and post-graduate students, this work presents all the information regarding the project and construction of a scaled reverberant chamber (1:6 of a 200 m3 real chamber). Besides, a methodology is presented regarding the qualification and adequacy of the internal acoustic field, based on the guidance of ISO-354. On the other hand, experimental results for the miniaturized chamber are presented and discussed, which characterize and validate the usage of the coconut fiber panels, developed by the Acoustics and Vibration Group of the Federal University of Pará. Finally, numerical results, based on Ray Tracing Methods, are presented and compared to those measured for the scaled chamber, seeking the validation of the developed numerical model.