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Continuous Scanning Technique with Barkhausen Magnetic Noise for Carbon Steel Sheets

Leosdan Figueredo Noris, Linilson Rodrigues Padovese, Sérgio Souto Maior Tavares, Juan Manuel Pardal
2019 Materials Research  
The signal processing method developed by Padovese et al. 15 was used in the analysis of CSMBN signals.  ... 
doi:10.1590/1980-5373-mr-2018-0366 fatcat:4y3vtcgpzvcw5jimscrzl7mphe

An Autonomous Underwater Recorder Based on a Single Board Computer

Manuel Caldas-Morgan, Alexander Alvarez-Rosario, Linilson Rodrigues Padovese, Z. Daniel Deng
2015 PLoS ONE  
As industrial activities continue to grow on the Brazilian coast, underwater sound measurements are becoming of great scientific importance as they are essential to evaluate the impact of these activities on local ecosystems. In this context, the use of commercial underwater recorders is not always the most feasible alternative, due to their high cost and lack of flexibility. Design and construction of more affordable alternatives from scratch can become complex because it requires profound
more » ... ledge in areas such as electronics and low-level programming. With the aim of providing a solution; a well succeeded model of a highly flexible, low-cost alternative to commercial recorders was built based on a Raspberry Pi single board computer. A properly working prototype was assembled and it demonstrated adequate performance levels in all tested situations. The prototype was equipped with a power management module which was thoroughly evaluated. It is estimated that it will allow for great battery savings on long-term scheduled recordings. The underwater recording device was successfully deployed at selected locations along the Brazilian coast, where it adequately recorded animal and manmade acoustic events, among others. Although power consumption may not be as efficient as that of commercial and/or micro-processed solutions, the advantage offered by the proposed device is its high customizability, lower development time and inherently, its cost. Fig 2. Experimental frequency response obtained with a particular tuning of the signal-conditioning board.
doi:10.1371/journal.pone.0130297 pmid:26076479 pmcid:PMC4468060 fatcat:qoxkntvwgrbqjlwylcqfagxx3y

New Technique for Evaluation of Global Vibration Levels in Rolling Bearings

Rui Gomes Teixeira de Almeida, Silmara Alexandra da Silva Vicente, Linilson Rodrigues Padovese
2002 Shock and Vibration  
In the last years new technologies and methodologies have been developed for increasing the reliability of fault diagnosis in mechanical equipment, mainly in rotating machinery. Global vibration indexes as RMS, Kurtosis, etc., are widespread known in industry and in addition, are recommended by international norms. Despite that, these parameters do not allow reaching reliable equipment condition diagnosis. They are attractive for their apparent simplicity of interpretation. This work presents a
more » ... discussion about the diagnosis possibilities based on these traditional parameters. The database used comprises rolling bearings vibration signals taking into account different fault conditions, several shaft speeds and loading. The obtained results show that these global vibration parameters are limited regarding correct fault diagnosis, especially in initial faults condition. As an alternative method a new technique is proposed. This technique seeks to obtain a global parameter that makes better characterization of fault condition. This methodology, named Residual Energy, uses integration of the difference between the power spectrum density of the fault condition and the normal one. The results obtained with this technique are compared with the traditional RMS and Kurtosis.
doi:10.1155/2002/647652 fatcat:5u7je3a5arhz5iukvylmrkdbki

Ruido magnético Barkhausen para el estudio de la anisotropía magnética en aceros inoxidables

Miriam Rocío Neyra Astudillo, Nicolás Nuñez, Maria Isabel López Pumarega, José Ruzzante, Linilson Padovese Rodrigues
2018 Matéria  
RESUMEN El ruido magnético Barkhausen (RMB) es un fenómeno que ocurre en materiales ferromagnéticos cuando se someten a campos magnéticos lentamente variables, generándose cambios en su magnetización, produciéndose "saltos" discretos. Estos saltos se generan por el movimiento de las paredes de los dominios magnéticos. Se detectan colocando una pequeña bobina sobre la superficie de la muestra. El movimiento de las paredes es regulado por la microestructura del material (precipitados, tamaño de
more » ... ano, tensiones residuales, etc.). Es esta manera indirecta la que permite caracterizar al material. En este trabajo se presentan las mediciones del RMB para estudiar la anisotropía magnética, inducida por el proceso de laminación, y los cambios producidos por deformación plástica uniaxial en probetas de aceros inoxidables ferríticos AISI: 409, 430, 441A. Las mediciones se realizaron a diferentes porcentajes de deformación, con el fin de observar cómo cambian las características de las señales de RMB. Se presentan también los estudios métalográficos y de dureza. Los resultados muestran una clara tendencia en relación con la dirección de los esfuerzos principales.
doi:10.1590/s1517-707620180002.0452 fatcat:nalgoup2r5edvi7a63lp32aptu

Comportamiento magnético del acero AISI 304 en ensayos de tracción uniaxial

Miriam Rocío Neyra Astudillo, Hugo Juan Scagnetti, Nicolás Nuñez, Guido Ferrari, Maria Isabel López Pumarega, Martin Gomez, José Ruzzante, Linilson Padovese Rodrigues
2018 Matéria  
RESUMEN Durante el proceso de magnetización de un material ferromagnético, las paredes de los dominios magnéticos son forzadas a moverse bajo la influencia del campo magnético. Para que las paredes se puedan mover deben superar la resistencia producida por los puntos de anclaje (borde de grano, dislocaciones, inclusiones, etc.), ocasionando saltos discretos en la magnetización. Estos saltos se pueden detectar con una bobina sensora colocada sobre la superficie de la muestra, que los transforma
more » ... n pulsos de voltaje. Estos últimos son conocidos como Ruido Magnético Barkhausen (RMB). En este trabajo se continúa el estudio de ensayos de tracción uniaxial, hasta rotura, en probetas de acero AISI 304 (no magnético), en las cuales, como consecuencia de la deformación, aparece una fase ferromagnética que sí produce RMB. Las mediciones se realizaron a diferentes cargas con el fin de observar cómo cambiaban las características del RMB. A partir de las señales obtenidas en las mediciones, se diseñó un filtro digital con el propósito de eliminar todo tipo de señal espuria e individualizar el RMB. Para tal propósito se utilizó un filtro digital Butterworth con banda pasante (2- 200) kHz. La selección del tipo de filtro se debe a que éste presenta una respuesta prácticamente constante hasta la frecuencia de corte, obteniéndose una respuesta plana a lo largo de la banda pasante. Para cada valor de carga se analizaron por separado las señales de RMB respecto de las etapas de aumento y disminución del campo magnético de excitación. Con el objetivo de caracterizar cada etapa, se estimaron diversos parámetros estadísticos que fueron evaluados en función de la deformación aplicada. Por último se calculó la evolución temporal de las señales y su función cuadrática media (RMS) para cada etapa de la magnetización, realizándose la correlación cruzada con el propósito de evaluar el grado de semejanza existente entre cada parte de la señal.
doi:10.1590/s1517-707620180002.0451 fatcat:44x6baz3gnakfed45cr454ne2y

Correlation between Martensitic Phase Transformation and Magnetic Barkhausen Noise of AISI 304 Steel

Miriam Rocío Neyra Astudillo, Marcelo Núñez Nicolás, José Ruzzante, Martín Pedro Gómez, Guido Claudio Ferrari, Linilson Rodrigues Padovese, María Isabel López Pumarega
2015 Procedia Materials Science  
The movement of magnetic domain walls can be disturbed by material defects, also named pinning sites. When the magnetic field is changing, the domain walls move by "jumps" over these pinning sites. These jumps produce the so named magnetic Barkhausen noise (MBN). During walls movements also low amplitude and high frequency elastic waves are generated, they are called magnetic acoustic emission (MAE). Both MBN and MAE are technological and efficient alternatives of low cost in the study of
more » ... agnetic materials which suffer degradation by plastic deformation, presence of inclusions, different stresses configurations, etc., depending on their micro structural characteristics. For austenitic metastable stainless steel (no magnetic), plastic deformation induces martensitic phase transformation (ferromagnetic). The aim of this work is to correlate the MBN with the plastic deformation and martensitic phase transformation of AISI 304 stainless steel. Standard test samples were submitted to uniaxial tensile strength with different load schedules up to rupture. At every instant the MBN produced was registered. Then MBN was correlated with the steel microstructure when the martensitic phase was growing.
doi:10.1016/j.mspro.2015.05.014 fatcat:fkij76fxsfguffccuzcqfk4cuy

Sistema digital de pesquisa de vazamentos de água: desenvolvimento de plataforma, gravações e análises de sinais

Allan Saddi Arnesen, Linilson Rodrigues Padovese, Marcelo Kenji Miki, Marcelo Aparecido dos Santos Carvalho
2015 Revista DAE  
Resumo A pesquisa de vazamentos não visíveis por métodos acústicos em sistemas de abastecimento de água é dependente do treinamento, da experiência e da capacidade auditiva dos técnicos. Contudo, os sinais acústicos emitidos pelos vazamentos e transmitidos à superfície dos pavimentos possuem características espectrais que podem ser utilizadas para identificação de vazamentos de água. O desenvolvimento de um sistema baseado no reconhecimento de padrões dos sinais acústicos, que opere de forma
more » ... ependente ou colaborativa ao técnico, pode aumentar a eficiência do diagnóstico, além de reduzir custos com mão de obra e manutenção. Este trabalho apresenta uma Plataforma Digital de Pesquisa de Vazamentos (PDPV) desenvolvida para gravar sinais acústicos de vazamentos, visando à criação de um banco de dados de sinais com informações úteis à identificação de vazamentos de água. A potencialidade dessa plataforma é apresentada na forma de estudos de situações com que os técnicos de pesquisa de vazamento se deparam constantemente. Abstract The non-visible leakage research by acoustic methods in water supply systems is dependent on the training, experience and hearing ability of technicians. However, the acoustic signals transmitted by the leak and the surface of pavements have spectral characteristics that can be used to identify water leaks. The development of a system based on recognition of acoustic signals patterns that operate independently or collaboratively to the Sistema digital de pesquisa de vazamentos de água: desenvolvimento de plataforma, gravações e análises de sinais Digital system for water leakage research: platform development, signal recording and analysis
doi:10.4322/dae.2015.003 fatcat:b2rzy2nhyngaflqcdl33qqcvc4

Effect of Shot Peening Treatment on Residual Stress and Magnetic Barkhausen Noise of AISI 201LN and AISI 304L Stainless Steels

Marcel Freitas de Souza, Juan Manuel Pardal, Hugo Ribeiro da Igreja, Linilson Rodrigues Padovese, Maria Cindra Fonseca
2022 Materials Research  
This work evaluates microstructural changes and residual stresses on surface samples of AISI 201LN and 304L subjected to shot peening. The residual stresses were measured by Xray diffraction and magnetic Barkhausen noise (MBN) in different shot-peened conditions. The results showed that the 201LN steel presented more martensite than the 304L steel in the initial condition, but with lower δferrite contents. These ferromagnetic phases were present in a low amount with high tensile residual
more » ... s due to brush cleaning and light coldrolling in the final stage of the fabrication process. The shot peening process promoted compressive residual stresses mainly in the δferrite. However, some "fresh" martensite exhibited tensile residual stress represented by higher and thinner peaks, which together with the low-intensity amplitude in the neighborhood, represented all formed martensite. Thus, small microstructural changes provoked high residual stresses behavior, which can be detected in ferromagnetic phases by MBN.
doi:10.1590/1980-5373-mr-2021-0341 fatcat:siiloockjvdrrixryxqjkeze7e

EFEITO DA DISTÂNCIA INTERLAMELAR DA PERLITA DE UM AÇO EUTETÓIDE NA DUREZA, NA SATURAÇÃO MAGNÉTICA E NO RUÍDO MAGNÉTICO DE BARKHAUSEN

Ana Paula Gonçalves Chaves, Lucas Pintol Nishikawa, Hélio Goldenstein, Linilson Rodrigues Padovese
2017 Anais do Congresso Anual da ABM   unpublished
Resumo A pesquisa relativa ao transporte ferroviário no Brasil tem se intensificado nos últimos anos visando principalmente a melhoria no desempenho do par roda-trilho. Isso se deve a demanda de se transportar cada vez mais carga por eixo visando uma redução no custo de transporte. Através de mudanças na microestrutura do material ou de mudanças na composição das ligas utilizadas na fabricação pode se aumentar a resistência do par roda-trilho. Neste trabalho foi analisada a influência de
more » ... tes microestruturas (puramente perlíticas e perlíticas-bainíticas), obtidas através de tratamento térmico por dilatometria, nas propriedades de um aço alto carbono similar ao utilizado em rodas convencionais classe C destinadas a implementação pesada com altas cargas e baixas velocidades. Foram realizados tratamentos isotérmicos em dez temperaturas diferentes para um aço eutetóide. As análises incluíram técnicas metalográficas (definição de fases presentes e distância interlamelar da perlita), ensaios mecânicos de dureza e ensaios magnéticos (saturação magnética e ruído de Barkhausen). Palavras-chave: Transformação de fase; Distância interlamelar da perlita; Ruído magnético de Barkhausen. THE INFLUENCE OF PEARLITE LAMELLAR DISTANCE ON HARDNESS, MAGNETIC SATURATION AND MAGNETIC BARKHAUSEN NOISE Abstract Research about rail transport in Brazil has been intensified recently due the need to improve the wheel-rail performance, considering the demand of increasing axle load aiming for a transportation cost reduction. Changes in the material microstructure or in the alloys composition can improve the wheel-rail resistance. A eutectoid steel similar to that used in conventional class C wheels (designed to heavy implementation with high loads and low speeds) was submitted to isothermal heat treatments applying dilatometry techniques at ten different cycles. Different microstructures (purely pearlitic and pearlitic-bainitic) were obtained and their influence in the mechanical and magnetic properties was analyzed. The analysis included metallographic techniques (identification of phases and pearlite lamellar distance), mechanical testing and magnetic testing (magnetic saturation and magnetic Barkhausen noise).
doi:10.5151/1516-392x-27955 fatcat:pl7x5p5jdzgvxdu3ky5mlfxa3y