ABSTRACT The present study focuses on vibration exposure and its impact on occupational health, contrasting the results with previous research. Workers in a specific workshop were investigated, assessing their vibration exposure, working hours and risk perception. A mixed approach was used, collecting data through structured surveys and inferential statistical analysis. The results indicate that 80% of the workers are exposed to vibration to some extent, with 10% exposed half the time and 6% almost always. However, no significant correlations were found between vibration exposure and other factors such as musculoskeletal health or reduced work activity. These discrepancies with previous research suggest demographic and occupational variations among the samples studied. It is concluded that it is critical to address musculoskeletal health in a comprehensive manner, implementing effective control measures to prevent mechanical vibration-related injuries.

RESUMEN Este trabajo aborda los desafíos del estrés laboral en docentes universitarios, analizando su impacto en la salud mental y el desempeño laboral. El objetivo es identificar las causas y consecuencias del estrés en este grupo y proponer medidas para mitigarlo. Se realizó una investigación no experimental con enfoque mixto, utilizando análisis descriptivo y relacional. Se aplicaron encuestas a 31 docentes, utilizando el cuestionario alemán Effort-Reward Imbalance y la escala de ansiedad de Zung. Los resultados muestran una correlación entre la carga laboral, la falta de reconocimiento y el nivel de estrés. Se concluye que es necesario abordar los factores psicosociales en el entorno laboral para promover un ambiente saludable y apoyar el bienestar de los docentes, lo que a su vez beneficiará la calidad educativa.

Abstract The present article analyzes the relationship between Explosive Detonation Velocity (VOD), vibration, and noise generated in 16 drilling and blasting tests in two arched horizontal galleries located at different altitudes with respect to the city of Zaruma, which is situated at an altitude of 1,194 meters above sea level. Nine tests were conducted in the working face called "Apófisis," located at an altitude of 1,155 meters above sea level and 1,650 meters horizontally from the center of Zaruma. The following seven tests were carried out in the "Matamoros" face, located at an altitude of 1,116 meters above sea level and 1,389 meters horizontally from the center of Zaruma. In the "Apófisis" face, two explosive initiation systems were used: the conventional system with detonators and slow fuse, and the assembled system with quick ignition fuse, connectors, slow fuse, and detonators. The same two explosive initiation systems were also used in the "Matamoros" face. The drilled holes had a diameter of 38 mm and depths of 1.10 m and 1.50 m, aiming to maintain the horizontal shape of the gallery and parallelism between each hole (with some cases having angles of deviation ranging from 23 to 26 degrees). Both ANFO and Agricultural Ammonium Nitrate explosives were used, placed under compressed air pressure using a "gun" type pneumatic loader. The recorded data includes a minimum VOD of 3,950 m/s, a maximum VOD of 5,310 m/s, a minimum resultant vibration of 2.17 mm/s, a maximum resultant vibration of 11.5 mm/s, and minimum noise levels of 164 dB up to a maximum of 195 dB. These vibration and noise levels were compared with the current national regulations in Ecuador and international regulations in the United States. The analysis indicates that the influence of the blast in terms of VOD, vibration, and noise is within a range of 60 m to 80 m around the explosion, which does not affect the nearest infrastructure related to mining operations (offices and camps) and does not propagate to the city of Zaruma. It is important to highlight that tests using ANFO as a bottom and column charge showed lower vibrations, lower detonation velocity (VOD), and lower noise compared to the use of emulsions and agricultural ammonium nitrate.

Resumen El presente artículo analiza la relación entre la Velocidad de Detonación del Explosivo (VOD), la vibración y el ruido generados en 16 ensayos de perforación y voladura en dos galerías horizontales abovedadas ubicadas a diferentes altitudes con respecto a la ciudad de Zaruma, que se encuentra a una altitud de 1.194 m.s.n.m. Se realizaron 9 ensayos en el Frente de trabajo denominado "Apófisis", ubicado a una altitud de 1.155 m.s.n.m. y a una distancia horizontal de 1.650 m. del centro de la ciudad de Zaruma. Los siguientes 7 ensayos se llevaron a cabo en el Frente "Matamoros", ubicado a una altitud de 1.116 m.s.n.m. y a una distancia horizontal de 1.389 m. del centro de la ciudad de Zaruma. En el Frente "Apófisis", se utilizaron dos sistemas de iniciación de explosivos: el convencional, con fulminante y mecha lenta, y el ensamblado, con mecha rápida de ignición, conectores, mecha lenta y fulminantes. En el Frente "Matamoros", también se utilizaron estos dos sistemas de iniciación de explosivos. Los barrenos perforados tenían un diámetro de 38 mm y profundidades de 1.10 m. y 1.50 m. Se utilizaron tanto ANFO como Nitrato de Amonio Agrícola como explosivos, colocados bajo presión de aire comprimido utilizando un cargador neumático tipo "pistola". Los datos registrados incluyen una VOD mínima de 3.950 m/s hasta una VOD máxima de 5.310 m/s, una vibración resultante mínima de 2,17 mm/s y una vibración resultante máxima de 11,5 mm/s, y niveles de ruido mínimos de 164 dB hasta un máximo de 195 dB. Estos niveles de vibración y ruido se compararon con la normativa nacional vigente en Ecuador y la normativa internacional de Estados Unidos. El análisis indica que la influencia de la explosión de las voladuras en términos de VOD, vibración y ruido se encuentra en un rango de 60 m. a 80 m. alrededor de la explosión, lo que no afecta a la infraestructura más cercana propia de la labor minera y no se propaga hasta llegar a la ciudad de Zaruma. Es importante destacar que los ensayos con ANFO como carga de fondo y de columna presentaron menores vibraciones, menor velocidad de detonación (VOD) y menor ruido en comparación con el uso de Emulsiones y Nitrato de Amonio Agrícola.

RESUMEN Cuenca Ecuador es una Zona de Alta Sismicidad, de ahí la necesidad de realizar estudios de la amenaza, vulnerabilidad y riesgo sísmico, como son los Estudios de Microzonificación Sísmica. Este trabajo, estudia el comportamiento de seis lugares de la Ciudad de Cuenca frente a dos eventos sísmicos de magnitud 6.9 cerca de Guayaquil y otro de 5.2 en La Maná, Cotopaxi, para lo cual se instaló equipos de medición de vibración ambiental en cada lugar, realizando la respectiva calibración y fijación; posteriormente los datos obtenidos fueron procesados y analizados mediante un filtrado para la eliminación del ruido sísmico, obteniendo aceleraciones y períodos; también se estudió los efectos de sitio calculando la Velocidad de Onda de Corte Vs30, Relación H/V, así como el Factor de Amortiguamiento del Suelo. A partir de los resultados, se concluye que existe una heterogeneidad en la respuesta sísmica entre los diferentes lugares de estudio, recomendando generar una base de datos de Registros de Vibraciones Ambientales enfocada a Estudios de Microzonificación Sísmica, continuar desarrollando estudios de vibración ambiental, así como compararlos y relacionarlos con resultados de Estudios Geotécnicos.

ABSTRACT Cuenca Ecuador is a High Seismic Zone, hence the need to carry out studies of the threat, vulnerability and seismic risk, such as Seismic Microzoning Studies. This work studies the behavior of six places in the City of Cuenca in the face of two seismic events of magnitude 6.9 near Guayaquil and another of 5.2 in La Maná, Cotopaxi, for which environmental vibration measurement equipment was installed in each place. performing the respective calibration and fixation; Subsequently, the data obtained were processed and analyzed by filtering to eliminate seismic noise, obtaining accelerations and periods. Site effects were also studied by calculating the Shear Wave Velocity Vs30, H/V Ratio, as well as the Damping Factor Soil. From the results, it is concluded that there is heterogeneity in the seismic response between the different study locations, recommending generating a database of Environmental Vibration Records focused on Seismic Microzoning Studies, continuing to develop environmental vibration studies, as well as compare and relate them with results of Geotechnical Studies.

Abstract Nowadays, despite the implementation of new wind farms in Brazil, it still is difficult to form partnerships with companies in the sector, which significantly contributes to the gap in information provided by national literature and the lack of knowledge about the mechanical behavior of wind turbines subjected to transient wind effects. Therefore, through a Research and Development Project to optimize and improve modeling in wind systems, the Brazilian electric power company Eletrobras Furnas aims to facilitate the construction of smaller wind turbines to supply energy to regions far from the Brazilian coast that do not have high generation potential due to the incidence of low-speed winds. Two relevant aspects directly linked to the performance of this kind of structures are: (i) determining their natural frequency and (ii) ensuring that this frequency does not coincide with any external vibration frequency that the structure may experience in its lifetime. Wind turbines are complex systems with many degrees of freedom and their own frequencies associated with the respective mode shapes in which they naturally vibrate. These frequencies are inversely related to the mass and directly related to the stiffness of the structure. Thus, through numerical modeling using the Finite Element Method, the present article aims to list some of the main factors that can affect the prediction of the natural frequency of a real-scale wind turbine prototype and to evaluate its dynamic behavior, considering its rotor revolution frequency, its blade passing frequency and the wind characteristics of its operating area. Nowadays Brazil sector effects Therefore lowspeed low speed winds i (i ii (ii lifetime vibrate Thus Method realscale real scale area

ABSTRACT Identifying the presence, size, type and location of voids in an endodontic obturation is of great clinical importance because it enables evaluation of the three-dimensionality of the sealing techniques, which can be related to the success of the endodontic treatment. Aim To analyze by micro-CT the presence of voids in lower single-rooted premolar root canal obturations prepared using the single cone and ultrasound vibration technique. Materials and methods Twenty extracted single-rooted lower premolars were selected, and the root canal prepared surgically and chemically. In GROUP 1 - Without Vibration, the canal was obturated with a single cone and bioceramic, without applying vibration. In GROUP 2 - With Vibration, the gutta-percha cone inside the root canal was held with a cotton plier to which ultrasound vibration was applied for 3 periods of 3 seconds each. A micro-CT scanner was used to acquire and reconstruct images for analysis. Results No significant difference was found between obturation techniques, though there were differences between thirds, with the cervical third having a higher percentage of voids than the middle and apical thirds. Conclusions The results suggest that the volume of closed, open and total voids does not differ between treatments with and without ultrasound vibration. In the cervical third, the highest volume of voids was related to oval geometry in the teeth evaluated.

RESUMEN La presencia de vacíos en la obturación endodóntica, su tamaño y el tipo y localización tiene gran importancia clínica ya que permite evaluar la tridimensionalidad de las técnicas de sellado y relacionarlas con el éxito del tratamiento endodóntico. Objetivo analizar mediante microtomografía la presencia de vacíos en la obturación del conducto radicular de premolares inferiores unirradiculares, utilizando la técnica de cono único y vibración con ultrasonido. Materiales y Método se seleccionaron 20 premolares inferiores unirradiculares a los que se les realizó la preparación quirúrgica y química del conducto radicular. Se realizó la obturación con cono único y biocerámico GRUPO 1- sin vibración. En el GRUPO 2 - con vibración se aplicó vibración por ultrasonido, se tomó del cono de gutapercha colocado en el interior del conducto con pinza de algodón que fue vibrada durante 3 períodos de 3 segundos cada uno. Las mismas fueron adquiridas y reconstruidas en un microtomógrafo para posterior análisis de las imágenes obtenidas. Resultados No se evidenciaron diferencias significativas entre ambas técnicas de obturación comparadas, pero si entre los tercios analizados, siendo el cervical el que mayor porcentaje de vacíos presenta en comparación a los cortes correspondientes al tercio medio y apical. Conclusiones Los resultados sugieren que el volumen de vacíos cerrados, abiertos y total no varía en los tratamientos donde se aplica vibración por ultrasonido. En el tercio cervical, el mayor volumen de vacíos se relaciona con la geometría oval que presentaron las piezas dentarias evaluadas en este estudio.

Abstract Sarcopenia is a pathology resulting from a progressive and severe loss of muscle mass, strength, and function in the course of aging, which has deleterious consequences on quality of life. Among the most widespread studies on the issue are those focused on the effect of different types of physical exercise on patients with sarcopenia. This randomized controlled study aimed to compare the effects of a whole-body vibration exercise (WBV) session on the inflammatory parameters of non-sarcopenic (NSG, n=22) and sarcopenic elderly (SG, n=22). NSG and SG participants were randomly divided into two protocols: intervention (squat with WBV) and control (squat without WBV). After a one-week washout period, participants switched protocols, so that everyone performed both protocols. Body composition was assessed by dual-energy radiological absorptiometry (DXA) and function through the six-minute walk test (6MWD) and Short Physical Performance Battery (SPPB). Plasma soluble tumor necrosis factor receptors (sTNFR) were determined by enzyme-linked immunosorbent assay (ELISA) and measured before and immediately after each protocol. After exercise with WBV, there was an increase in sTNFR2 levels in the NSG (P<0.01; d=-0.69 (-1.30; -0.08) and SG (P<0.01, d=-0.95 (-1.57; -0.32) groups. In conclusion, an acute session of WBV influenced sTNFr2 levels, with sarcopenic individuals showing a greater effect. This suggested that WBV had a more pronounced impact on sTNFr2 in those with loss of muscle strength and/or physical performance. Additionally, WBV is gaining recognition as an efficient strategy for those with persistent health issues. mass aging life sarcopenia wholebody whole body (WBV nonsarcopenic non NSG, (NSG n=22 n22 n 22 SG, (SG n=22. . protocols squat WBV. oneweek one week period dualenergy dual energy DXA (DXA sixminute six minute 6MWD MWD (6MWD SPPB. SPPB (SPPB) sTNFR (sTNFR enzymelinked enzyme linked ELISA (ELISA protocol P<0.01 P001 P 0 01 (P<0.01 d=0.69 d069 d d= 0.69 69 d=-0.6 1.30 130 1 30 (-1.30 0.08 008 08 -0.08 P<0.01, d=0.95 d095 0.95 95 d=-0.9 1.57 157 57 (-1.57 0.32 032 32 -0.32 groups conclusion sTNFr andor or performance Additionally issues n=2 n2 2 (SPPB P<0.0 P00 (P<0.0 d=0.6 d06 069 0.6 6 d=-0. 1.3 13 3 (-1.3 0.0 00 -0.0 d=0.9 d09 095 0.9 9 1.5 15 5 (-1.5 0.3 03 -0.3 n= P<0. P0 (P<0. d=0. d0 06 0. d=-0 1. (-1. -0. 09 P<0 (P<0 d=0 d=- (-1 -0 P< (P< (- - (P (

Abstract This work aims the assessment of the dynamic structural response of reinforced concrete floors subjected to rhythmic human activities, based on the use of biodynamic models, in order to consider the people-structure interaction effect. Initially, an experimental modal analysis on the investigated floor , with dimensions of 16m x 35m, was performed, in order to identify and assess the global dynamic behaviour of the structure. In sequence, a finite element model was developed and calibrated through experimental results. After that, based on forced vibration analyses, the floor dynamic response was determined (displacements and accelerations). It is concluded that the biodynamic systems modelling induced significant attenuations on the structural response when compared to those calculated based on the use of traditional “only force” models. activities models peoplestructure people structure effect Initially m 35m performed sequence results analyses displacements accelerations. accelerations . accelerations) only force

Resumo Este trabalho tem como objetivo a avaliação da resposta dinâmica de pisos de concreto armado submetidos a atividades humanas rítmicas, com base no uso de sistemas biodinâmicos, a fim de analisar o efeito de interação pessoa-estrutura. Inicialmente, realizou-se uma análise modal experimental sobre o piso investigado, com dimensões de 16m x 35m, visando identificar e avaliar o comportamento dinâmico global da estrutura. Em seguida, um modelo de elementos finitos foi desenvolvido e calibrado com base nos resultados experimentais. Posteriormente, a partir das análises de vibração forçada, a resposta dinâmica do piso foi determinada (deslocamentos e acelerações). Conclui-se que a modelagem dos sistemas biodinâmicos induziu atenuações significativas sobre a resposta estrutural quando comparadas àquelas calculadas via utilização de modelos tradicionais de força-rítmica. rítmicas pessoaestrutura. pessoaestrutura pessoa estrutura pessoa-estrutura Inicialmente realizouse realizou se investigado m 35m seguida experimentais Posteriormente forçada deslocamentos acelerações. acelerações . acelerações) Concluise Conclui forçarítmica. forçarítmica força rítmica. rítmica força-rítmica

Abstract The construction of high-rise buildings has emerged as a constructive trend worldwide, and excessive vibration problems due to wind actions are becoming increasingly frequent. The Brazilian design standard NBR 6123 recommends that the transfer of wind actions used for structural analysis be carried out based on the pressure coefficients along the building facades for static analyses and considers their non-deterministic dynamic behaviour through a stochastic modelling method of the wind velocity field. To present an alternative approach to this methodology, this study aims to investigate the non-deterministic dynamic structural response of a real reinforced concrete building, considering the soil-structure interaction effect, using the pressure coefficients obtained through different methodologies such as numerical simulations using Computational Fluid Dynamics (CFD), international databases, and the recommendations of the Brazilian standard NBR 6123. highrise high rise worldwide frequent 612 nondeterministic non deterministic field methodology soilstructure soil structure effect CFD, CFD , (CFD) databases 61 (CFD 6

Resumo A construção de edifícios altos tem se mostrado uma tendência construtiva ao redor do mundo, e vibrações excessivas oriundas das ações do vento tem se tornado cada vez mais frequentes. A norma brasileira de projeto NBR 6123 recomenda que a transferência das ações de vento utilizadas para análise estrutural seja realizada com base nos coeficientes de pressão ao longo das fachadas do edifício, para análises estáticas, e considera o seu comportamento dinâmico não determinístico através de um método de modelagem estocástica do campo de velocidade do vento. Objetivando apresentar uma abordagem alternativa para esta metodologia, este estudo tem como objetivo investigar a resposta estrutural dinâmica não determinística de um edifício real de concreto armado, considerando o efeito da interação solo-estrutura, utilizando coeficientes de pressão obtidos por intermédio de metodologias distintas, tais como: simulações numéricas utilizando CFD (Computational Fluid Dynamics), bases de dados internacionais, e utilizando as recomendações da norma brasileira NBR 6123. mundo frequentes 612 estáticas metodologia armado soloestrutura, soloestrutura solo estrutura, estrutura solo-estrutura distintas Computational Dynamics, Dynamics , Dynamics) internacionais 61 6

Abstract This article aims to identify the presence of cracks in slender rotating beams (Euler Bernoulli) from the dynamic behaviour of cracked beams operating at low rotational speeds. For this purpose, the behavioural model of the cracked rotating beam developed by the authors in previous works is shown. The results of the mathematical model developed (natural frequencies) feed a novel meta-heuristic optimisation algorithm based on the survival tactics of rabbits against their predators: Artificial Rabbit Optimization (ARO). The application of this algorithm to the first two natural frequencies of vibration obtained with the analytical model and contrasted in previous works gives rise to the identification of the characteristic parameters of the crack contained in the beams. The estimation of the parameters: position along the beam and crack depth, show a high similarity with the initial data, which allows validating the application of the optimisation algorithm to the identification of cracks in this type of component as a first approach to a health monitoring method for more complex rotating cantilever beam structures. Euler Bernoulli speeds purpose shown metaheuristic meta heuristic predators ARO. ARO . (ARO) depth data structures (ARO

Wave physics describes physical systems in which a restoring force governs the oscillatory motion of the system around an equilibrium point. These oscillations manifest themselves in different types of waves and propagate at speeds associated with the different characteristics of the propagation medium. One of the phenomena that impresses by their symmetry and elegance are the Chladni patterns, which are even used as an indicator of quality in the manufacture of musical instruments. In this paper, a simple experimental apparatus and an interactive mathematical graphical interface, which was createad at the GeoGebra platform by equations solutions from the wave equation in square plates, were developed to study two dimensional Waves of the Chladni plates. Several Chladni figures were experimentally created from grains deposited on different metal plates under vibration. Square plates of different sizes with free edges were used to observe the ratio relationship between the resonance frequency of the stationary wave patterns and the inverse of the square of the side. It was found that the association between the experimental results and those obtained by computer modeling in the formation of Chladni figures allows for a better understanding of the principles that control the formation of these patterns. point medium instruments paper interface vibration side

A física ondulatória descreve sistemas físicos nos quais uma força restauradora comanda o movimento oscilatório do sistema em torno de um ponto de equilíbrio. Essas oscilações se manifestam em diferentes tipos de ondas e se propagam com velocidades associadas às distintas características do meio de propagação. Uma manifestação que impressiona pela simetria, pela própria elegância, são os padrões de Chladni, que inclusive são utilizados como indicador de qualidade na fabricação de instrumentos musicais. Neste trabalho são apresentados um aparato experimental simples e uma interface gráfica matemática interativa, desenvolvida na plataforma GeoGebra a partir das soluções da equação de onda em placas quadradas para explorar o estudo de ondas estacionárias bidimensionais das placas de Chladni. Várias Figuras de Chladni foram criadas experimentalmente a partir de grãos depositados sobre diferentes placas metálicas sujeitas à vibração. Foram utilizadas placas quadradas de diferentes tamanhos com extremidades livres com o objetivo de observar a relação de proporção entre a frequência de ressonância dos padrões de onda estacionária com o inverso do quadrado do lado. Foi constatado que a associação entre os resultados experimentais obtidos pela modelagem computacional na formação das Figuras de Chladni permite uma melhor compreensão dos princípios que controlam a formação desses padrões. equilíbrio propagação simetria elegância musicais interativa vibração lado

Abstract The use of computational simulation techniques is an important tool for the coffee harvesting issues, particularly the finite element method. The method is widely used in the structural analysis of agricultural machinery, as well as in the analysis of the stresses and vibrations of coffee branches and peduncles during the harvesting process. The present study aimed to develop three-dimensional finite element models of the plagiotropic branches of the Catuaí Vermelho variety of Arabica coffee in different positions along the orthotropic branches of the plant; considering high-fidelity models. Additionally, by considering the branches’ experimental properties (physical-mechanical), the natural frequencies and vibration modes of the branches were determined by means of computer simulations. First, the geometric properties of the coffee branches were obtained by means of two images taken using a professional camera to obtain the input data of the virtual simulation. For the mechanical properties, it was used a semi-analytical digital scale, to obtain the mass of the specimens. The modulus of elasticity was determined using a universal testing machine. The variability in the simulated natural frequencies could be identified, which was on the order of 30% for the first frequency, regardless of the position of the branch in the plant. These values were lower for the other frequencies. Linear regression fits showed a coefficient of determination, and correlation tests were used to verify the relationship between the values obtained numerically and experimentally, which were validated by using experimental data using the modal analysis techniques. issues machinery process threedimensional three dimensional plant highfidelity high fidelity Additionally physicalmechanical, physicalmechanical physical , (physical-mechanical) simulations First semianalytical semi analytical scale specimens machine identified 30 frequency determination experimentally (physical-mechanical 3

ABSTRACT In complex environments, beet harvesters vibrate strongly under the influence of multiple sources of excitation. The modal constraints of the harvester's frame were obtained using modal simulation, and the accuracy of the finite element model was verified through SIMO modal testing. Additionally, field experiments were conducted to collect the vibration signals of the harvester under various conditions. Time-domain analysis revealed that the RMS value of the frame's Z-axis acceleration was highest in sugar beet fields and lowest on unpaved roads. There is a correlation between the operation of working components and changes in amplitude. Frequency domain analysis determined that the main vibration frequency of the frame was in the range of 0–75 Hz, and the operating frequency of the engine (35 Hz) and the power input shaft (12.7 Hz) excites the constrained modal of the frame, which may lead to resonance. Integrating the results of the modal response and vibration testing provides a more comprehensive approach to studying the vibration characteristics of agricultural machinery. environments excitation s simulation Additionally conditions Timedomain Time frames Zaxis Z axis roads amplitude 075 0 75 0–7 Hz 35 (3 12.7 127 12 7 (12. resonance machinery 07 0– 3 ( 12. 1 (12 (1

ABSTRACT This article results from the analysis of blocks produced in industry using a hydraulic vibro-press machine and samples extracted from the block itself, therefore with the same trace and vibration/compaction process. The blocks and samples were subjected to axial compression resistance tests and the results were correlated. This fact is unprecedented in the literature, as blocks manufactured in industry and samples cut from the block itself were used for analysis. By correlating the compressive strength values of blocks BR4 and BR 16 and their respective samples at 02, 07 and 28 days; it was found that at 2 days the resistance of the sample is comparatively greater than the resistance of the entire block. After 28 days, the resistance ratio tends to decrease, remaining around 2.0. Drawing a parallel with the blocks, it is believed that this behavior is expected, since the traction and compression ratio at younger ages is also higher and reduces as the days go by, remaining in the range of 2, due to the ratio of gross area and net area. vibropress vibro press vibrationcompaction vibration compaction process correlated literature 1 02 0 decrease 20 2.0 expected by 2.

RESUMO O artigo traz resultados de análise de blocos produzidos em indústria por meio de máquina hidráulica vibro – prensa e de amostras extraídas do próprio bloco, logo com mesmo traço e processo de vibração/compactação. Os blocos e amostras foram submetidos à ensaios de resistência à compressão axial e os resultados foram correlacionados. Tal fato é inédito na literatura, pois empregou-se blocos fabricados em indústria e amostras cortadas do próprio bloco para as análises. Ao correlacionar os valores de resistência à compressão dos blocos BR4 e BR 16 e suas respectivas amostras aos 02, 07 e 28 dias; verificou-se que aos 02 dias a resistência da amostra é comparativamente maior que a resistência do bloco inteiro. Aos 28 dias a relação de resistência tende a diminuir, ficando em torno de 2,0. Traçando-se um paralelo com os blocos, acredita-se que esse comportamento é esperado, uma vez que a relação tração e compressão nas menores idades também é maior e se reduz com o passar dos dias, ficando na faixa de 2, devido a relação de área bruta e área líquida. vibraçãocompactação vibração compactação vibração/compactação correlacionados literatura empregouse empregou análises 1 0 2 verificouse verificou inteiro diminuir 20 2,0 Traçandose Traçando acreditase acredita esperado líquida

Vibration is everywhere in our everyday lives. Nowadays, with the advancement of computational methods and materials science, civil structures are increasingly flexible and slender. High structural flexibility leads to large vibration amplitudes that can be transmitted to people in buildings, causing discomfort, loss of work efficiency due to fatigue and even serious health changes. In this context, a numerical-computational approach is presented for the modal and transient analysis of Shear Building-type structures using the open-source program Scilab. The effect of damping on the structure is described by the Rayleigh damping model. A study with the TMD passive control system installed on top of the structure is presented. The TMD is a mass-spring system that serves to reduce the vibration amplitude of the main structural system. The numerical approach presented helps physics, and engineering students regarding vibration analysis of structural systems. The methodology described for dynamic analysis is relatively easy to implement computationally and the numerical results had good precision and agreed with the results available in the literature. lives Nowadays science slender buildings discomfort changes context numericalcomputational Buildingtype Building type opensource open source Scilab model massspring mass spring physics systems literature

A vibração está em toda parte em nossa vida cotidiana. Nos dias atuais, com o avanço de métodos computacionais e da ciência dos materiais, estruturas civis estão cada vez mais flexíveis e esbeltas. Uma elevada flexibilidade estrutural leva a grandes amplitudes de vibração que podem ser transmitidas às pessoas nos edifícios, causando desconforto, perda de eficiência no trabalho devido ao cansaço e até graves alterações de saúde. Nesse contexto, uma abordagem numérico-computacional é apresentada para a análise modal e transiente de estruturas do tipo shear building utilizando o programa livre Scilab. O efeito do amortecimento na estrutura é descrito pelo modelo de amortecimento de Rayleigh. Um estudo com o sistema de controle passivo AMS instalado no topo da estrutura é apresentado. O AMS é um sistema massa – mola que serve para reduzir a amplitude de vibração do sistema estrutural principal. A abordagem numérica apresentada vem a auxiliar os estudantes de física e das engenharias no que concerne à análise de vibração de sistemas estruturais. A metodologia descrita para análise dinâmica é relativamente de fácil implementação computacional e os resultados numéricos tiveram boa precisão e ficaram de acordo com os resultados disponíveis na literatura. cotidiana atuais materiais esbeltas edifícios desconforto saúde contexto numéricocomputacional numérico Scilab Rayleigh apresentado principal estruturais literatura

Abstract For the first time, this article uses higher-order IGA to study the high frequency of the functionally graded sandwich (FGS) square nanoplates with two different skin layers resting on elastic foundations. In this work, the elastic foundations use the Pasternak foundation (PF) model with a two-parameter as a spring stiffness ( k 1) and a shear layer stiffness ( k 2). The observation of small-scale effects in nanoplates is accomplished by incorporating nonlocal elasticity theory (NET) with a higher-order shear deformation theory (HSDT). The governing equation of nanoplates is derived from Hamilton's principle. An extensive parametric investigation has been conducted to illustrate the free vibration characteristics of FGS square nanoplates across both low and high frequency modes, placing a greater emphasis on the analysis of high frequency behaviour. Furthermore, the high eigenmodes and frequencies of the FGS circular/elliptical nanoplates are also added. Therefore, the findings presented here contribute to an improved understanding of the vibrations of FGS nanoplates at high frequencies. time higherorder higher order (FGS work PF (PF twoparameter parameter 1 2. 2 . 2) smallscale small scale NET (NET HSDT. HSDT (HSDT) Hamiltons Hamilton s principle modes behaviour Furthermore circularelliptical circular elliptical added Therefore (HSDT