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1
Content available Vibration reduction with rubber-metal cab supports
EN
This paper investigates the possibility of improving the vibration isolation of a tractor cab by changing the stiffness of its rubber-metal supports. A spectral analysis of the vibration isolation properties of these supports is presented. The research was conducted on a BELARUS 1221 tractor at idling, at the maximum engine speed, with no load. The cab was mounted on rubber-metal vibration absorbers of serial design with different rubber hardness. Measurements were made with a first class certified Oktava 101VM instrument with registration of RMS acceleration values, expressed in dB, in the frequency range of 8-1000 Hz. The instrument was set in "local vibration" mode. The AR2082M probe was attached to the respective measurement points using adhesive. Mathematical relationships are given to optimize the work on the development of a new and upgraded design of the rubber-metal supports in use. It is shown that varying the stiffness of the rubber-metal supports has different effects in the low and high frequencies of the spectrum. A stiff support is effective in damping low-frequency vibrations but degrades the support's properties in damping high-frequency vibrations, and vice versa. A soft support is more effective at higher frequencies and reduces the effectiveness of the support at lower frequencies.
PL
Niniejsza praca analizuje możliwość ulepszenia izolacji wibracji w kabinie ciągnika poprzez zmianę sztywności gumowo-metalowych wsporników. Przedstawiono analizę spektralną właściwości izolacji wibracji tychże wsporników. Związki matematyczne zostały podane w celu optymalizacji pracy nad stworzeniem nowego i ulepszonego projektu gumowo-metalowych wsporników. Wykazano, iż różnicowanie sztywności gumowo-metalowych wsporników daje różne efekty w niskich i wysokich spektrach częstotliwości. Sztywny wspornik jest skuteczny w wyciszaniu wibracji o niskiej częstotliwości, ale zmniejsza właściwości wyciszania wibracji o wysokiej częstotliwości i vice versa. Miękkie wsparcie jest bardziej efektywne przy wysokich częstotliwościach i redukuje skuteczność wspornika przy niskich częstotliwościach.
PL
Opracowanie nawiązuje do ogólnych wymagań zapisanych w "Prawie ochrony środowiska", dotyczących oceny standardów jakości środowiska odnoszących się do emisji drgań pochodzących od eksploatowanych dróg. Podano tu procedury przydatne w ocenianiu wpływu na budynki eksploatowane drgań generowanych przejazdami pojazdów w pobliżu tych budynków. Drgania takie są wymuszeniem kinematycznym budynku i mogą doprowadzać do jego uszkodzeń (rysy, uszkodzenia elementów architektonicznych, zarysowania w elementach konstrukcyjnych itp.). Z kolei drgania w budynku mogą wpływać na naruszenie warunków niezbędnego komfortu wibracyjnego. Mogą też naruszać wymagania odnoszące się do warunków pracy urządzeń wrażliwych na drgania w budynkach eksploatowanych. Zadaniem rzeczoznawcy jest opracowanie diagnozy, w wyniku której uzyskuje się informacje o tym, czy istnieje związek skutkowo-przyczynowy między naruszeniem warunków bezpiecznej eksploatacji budynku a działaniem źródła drgań. Zastosowanie procedur tu opisanych powinno ułatwić wykonanie takich diagnoz. Postępując według podanych procedur rzeczoznawca będzie stosował odpowiednie narzędzia diagnostyczne, o których niezbędne informacje również zamieszczono w niniejszym opracowaniu.
EN
The study refers to the general requirements of the Environmental Protection Law regarding the assessment of environmental quality standards relating to the emission of vibrations from the roads in use. The article discusses the useful procedures for assessing the impact of vibrations generated by passing vehicles near the buildings. Such vibrations are a kinematic excitation for the building and can lead to damage (Iike cracks, damage to architectural elements, scratches in structural elements, etc.). In turn, vibrations in the building may affect the violation of the conditions of the necessary vibration comfort. They may also violate the requirements relating to the working conditions of devices sensitive to vibrations in exploited buildings. The expert task is to develop a diagnosis, as a result of which information is obtained as to whether there is a cause-and-effect relationship between the violation of the conditions for the safe operation of the building and the operation of the source of vibration. The use of the procedures described here should facilitate such diagnoses. Following the given procedures, the expert will use appropriate diagnostic tools, and the necessary information described in this study.
EN
In industrial applications, worm gearboxes are a key element. In a worm gearbox, as the material of a worm wheel is softer than that of a worm screw, the worm wheel gear is vulnerable to failure through various modes like pitting, wearing out, or tooth breakage during the sliding process. Due to this, it is essential to monitor the failure of the worm wheel gear of the worm gearbox, and it has gained importance for the diagnosis of faults in gearboxes. The present work focuses on the investigation of the effect of worm wheel tooth breakage, worm wheel bearing outer race, and varying load on vibration signature amplitude and frequency domain statistical features such as root mean square (RMS), crest factor, kurtosis, mean, peak to peak, skewness, sample variance, and standard deviation. The experimental setup is fabricated to conduct the experimental trials. An OR34 FFT analyzer with NVGate software is used to acquire the frequency domain vibration signature. Experimental results show that captured vibration signature amplitude for healthy worm wheel and bearing increased as fault occurred on the worm wheel, and bearing and frequency domain statistical features value changed with the change in fault location in the worm gearbox.
EN
Reducing the effect of unwanted vibrations is an important topic in many engineering applications. In this paper we describe some recent developments in the area of passive vibration mitigation. This is based on a new device called the inerter which can be exploited in a range of different contexts. In this paper we consider two recent examples; (i) where a flywheel inerter is combined with a hysteretic damper, and (ii) in which a pivoted bar inerter is developed for a machining application. In both cases, experimental test results show that the devices can outperform existing methods.
EN
Road infrastructure is aimed to be sustainable construction in today’s condition of heavy traffic. Depending on geotechnical characteristics of soils there are chosen adequate techniques for compaction, meaning: type of compaction, equipment, compaction parameters and, if possible, computer aided acquisition and processing of data. This paper presents research results on the vibratory roller compaction process of road soils, from the point of view of process mathematically modeling and statistically modeling of process parameters interdependence. The obtained regression model is innovative one and fit for further application in optimization (by AI and IoT) of the compaction process. Good correlation of all the results (self-pulsation values) proves the adequate assumptions for both modeling and experimenting. Further development of this research is intended to develop a special software for direct correlation of road geographical position and soil characteristics to the compaction process parameters optimum values.
EN
In this paper, the performance and frequency bandwidth of the piezoelectric energy harvester (PZEH) is improved by introducing two permanent magnets attached to the proof mass of a dual beam structure. Both magnets are in the vicinity of each other and attached in such a way to proof mass of a dual beam so that they create a magnetic field around each other. The generated magnetic field develops a repulsive force between the magnets, which improves electrical output and enhances the bandwidth of the harvester. The simple rectangular cantilever structure with and without magnetic tip mass has a frequency bandwidth of 4 Hz and 4.5 Hz, respectively. The proposed structure generates a peak voltage of 20 V at a frequency of 114.51 Hz at an excitation acceleration of 1 g (g= 9.8 m/s2 ). The peak output power of a proposed structure is 25.5 µW. The operational frequency range of a proposed dual beam cantilever with a magnetic tip mass of 30 mT is from 102.51 Hz to 120.51 Hz, i.e., 18 Hz. The operational frequency range of a dual beam cantilever without magnetic tip mass is from 104.18 Hz to 118.18 Hz, i.e., 14 Hz. There is an improvement of 22.22% in the frequency bandwidth of the proposed dual beam cantilever with a magnetic tip mass of 30 mT than the dual beam without magnetic tip mass.
EN
The two dimensional temperature effect on the vibration is computed for the first time for a clamped triangular plate with two dimensional thickness. In the study we focused on isosceles, right-angled and scalene triangles only. The first three modes of vibration are computed on different variations of plate parameters using the Rayleigh-Ritz method. The objective of the study is to reduce the frequency of the plates. A comparative study of the frequencies with other available results well presents the objective of the study.
EN
Purpose: The operation of engineering structures may cause various type of damages like cracks, alterations. Such kind of defects can lead to change in vibration characteristics of cantilever beam. The superposition of frequency causes resonance leading to amplitude built up and failure of beam. The current research investigates the effect of crack dimensional parameters on vibrational characteristics of cantilever beam. Design/methodology/approach: The CAD design and FE simulation studies are conducted in ANSYS 20 simulation package. The natural frequencies, mode shapes and response surface plots are generated, and comparative studies are performed. The effect of crack dimensional parameters is then investigated using Taguchi Design of Experiments. The statistical method of central composite design (CCD) scheme in Response Surface Optimization is used to generated various design points based on variation of crack width and crack depth. Findings: The research findings have shown that crack depth or crack height have significant effect on magnitude of deformation and natural frequency. The deformation is minimum at 0.009 m crack height and reaches maximum value at 0.011 m crack height. Research limitations/implications: The crack induced in the cantilever beam needs to be repaired properly in order to avoid crack propagation due to resonance. The present study enabled to determine frequencies of external excitation which should be avoided. The limitation of current research is the type of crack studied which is transverse type. The effect of longitudinal cracks on vibration characteristics is not investigated. Practical implications: The study on mass participation factor has shown maximum value for torsional frequency which signifies that any external excitation along this direction should be avoided which could cause resonance and lead to amplitude build up. Originality/value: The beams are used in bridge girders and other civil structures which are continuously exposed to moist climate. The moisture present in the air causes corrosion which initiates crack. This crack propagates and alters the natural frequency of beam.
EN
This paper is devoted to the development of an effective system for monitoring the technical condition of the axle boxes of rolling stock. To this end, the possibility of solving problems of fault diagnostics based on the theory of fuzzy sets is considered. This allows one note such difficult-to-formalise factors as experience and intuition of a highly qualified expert specialist. It showed that an expert system-based monitoring approach allows evaluation of the technical condition of the axle boxes, characterised by internal and external operating uncertainty. It also proposed the use of parameters such as vibration and noise for comprehensive monitoring of the technical condition of axle box units together with temperature. Furthermore, the combination of these diagnostic parameters and expert system’s possibility to receive all necessary information about the condition of the most critical components of the axle boxes in real-time and analyse the changes in their operational parameters was explored. The stages of modelling an expert system in the Fuzzy Logic Toolbox package of the MATLAB computing environment are presented.
10
Content available remote Dynamic synchronization of vibration exciters of the three-mass vibration mill
EN
The problem of self-synchronization of a three-axis vibrating mill with four unbalance vibrators, which are actuated by independent asynchronous motors and have the same angular velocities, is considered in the paper. In self-synchronization, synchronization and phase matching of the vibrator is achieved due to the vibration of the system of bodies on which the vibrator is installed, that is, by providing a dynamic connection between them.
PL
W artykule analizowano problem synchronizacji trzyosiowego wibracyjnego młyna z czterema niezależnymi wibratorami. Samoczynna synchronizacja została osiągnięta dzięki dynamicznemu połączeniu między wibratorami i podłożem.
EN
The paper presents the concept of vibration measurement and reduction system for rails in hyperloop technology. It is based on the experience of measuring vibrations in high-speed rail, the first commercial magnetic rail, and vibration reduction systems for these rails. The authors outlined a conceptual vibration monitoring system based on the MQTT protocol and the vibration reduction method. The vibration reduction systems based on variable-characteristic silencers and solutions used in research centers, especially in CERNie and LIGO, were de-scribed.
12
Content available remote Vibroabrasive machining of large-size products on hydropulse drive machines
EN
The paper considers the issue of complex shape items surface depuration together with the most appropriate hydropulse drive future oriented equipment, used in order to address this challenge adequately. There had been considered the mathematical model of the vibration machine with complex space load, developed on the base of the structural chart and behavior pattern. There had been presented the results of the research of the test model plant with the hydro pulse drive for vibroabrasive depuration of the inner surface of the tubular items.
PL
W artykule rozważono zagadnienie kompleksowej obróbki powierzchni przedmiotów kształtowych wraz z najbardziej odpowiednim urządzeniem do sterowania przyszłościowym napędem hydropulsacyjnym. Rozważono matematyczny model maszyny wibracyjnej o złożonym obciążeniu przestrzeni, opracowanej na podstawie wykresu strukturalnego i wzoru zachowania. Przedstawiono wyniki badań modelu testowego z napędem hydropulsacyjnym do oczyszczania wibroabrazyjnego powierzchni wewnętrznej elementów rurowych.
13
Content available remote Noise and vibration analysis of a distribution transformer
EN
Transformer noise is a significant contribution to unwanted ambient noise, especially in the vicinity of the electrical transmission facility. It is therefore very important to get to know the mechanism of noise generation of the distribution transformer. As outcomes of this work, a finite element based multiphysics model is presented which provides a convenient and efficient toolchain for simulating the transformer sound emission mechanism. Finally, the operation of modelling chain is presented on a 200kVA distribution transformer simulation.
PL
Hałas transformatora ma znaczący wpływ na niepożądany hałas otoczenia, zwłaszcza w pobliżu instalacji przesyłowej prądu elektrycznego. Z tego powodu ważnym jest poznanie mechanizmu generowania szumu transformatora rozdzielczego. Jako wynik tej pracy przedstawiono model transformatora rozdzielczego 200 kVA oparty na analizie elementów skończonych, który zapewnia wygodny i wydajny zestaw narzędzi do symulacji mechanizmu emisji dźwięku z analizowanego urządzenia.
EN
Vehicle vibrations caused by poor haul road conditions create multiple negative effects for mines, including slower cycle times, increased maintenance, and operator injury. Vibration levels in vehicles result in part from road roughness. Mine roads are mainly constructed from in-pit materials that are more likely to deteriorate overtime and require frequent maintenance to maintain a smooth surface. The decision for when and where road maintenance is conducted is primarily based on visual inspections. This method can provide subjective, inaccurate, and delayed response to adverse conditions. The recent increase in vehicle telemetry data allows instant access to several types of data; mainly being used for haul fleet dispatching, collision avoidance, and geologic surveying, telemetry data has yet to see widespread use in road maintenance dispatching. This paper examines current road roughness characterization techniques and current telemetry data streams. An initial case study was conducted using vibration and Global Navigation Satellite System (GNSS) telemetry data to determine road roughness. Data from three haul trucks under normal operating conditions were collected over the course of a week. The results of this case study demonstrate localized vibration levels can be used to objectively identify rough roads. This can be further developed to dispatch road maintenance crews leading to overall reduced mining costs and increased operator health. The researches propose continuing to full scale test using data from an entire fleet and longer timeframe.
EN
In this paper the problem of vibration control of a multi-member column subjected to the specific load is investigated. The vibration control is realized with the use of the piezoceramic element in the form of a rod that is connected to the host structure by means of the pins strengthened by rotational springs. The Hamilton’s principle is used during formulation of the boundary problem. The results of the numerical simulations are focused on the correction of the characteristic curves shape at a different radius of the loading head.
16
Content available remote Drążenie tuneli technologią TBM
PL
W artykule została scharakteryzowana metoda wykonania tunelu z wykorzystaniem technologii TBM. Na przykładzie linii metra warszawskiego zaprezentowany został schemat wykonywania prac tą metodą oraz monitoring bezpieczeństwa przylegającej infrastruktury. Metoda ta jest również z powodzeniem wykorzystywana do drążenia tuneli drogowych, wodociągowych, kanalizacyjnych, hydroenergetycznych czy wielozadaniowych. Za pomocą technologii TBM utworzono już 369 projektów tuneli metra o długości ponad 880 km, 440 km tuneli kolejowych i 171 km drogowych. Łącznie tą technologią wydrążono ponad 1900 km tuneli na całym świecie [7]. Przeważnie jest ona bardziej ekonomiczna i efektywna w stosunku do metod tradycyjnych (odkrywkowych). Nie powoduje nadmiernych utrudnień w komunikacji transportu ulicznego, a w ciągu doby może powstać nawet trzykrotnie dłuższy tunel, aniżeli ten wykonany w tradycyjny sposób. Ponadto, co istotne z punktu widzenia ekonomicznego, całkowity koszt wydrążenia metra technologią TBM jest niższy [7].
EN
The article presents a procedure for vibration analysis of the device based on measured data in simulated operating modes. Subsequently, the criterion of fatigue damage is formulated because this mechanism can be induced or accelerated by recognized operating deflection shapes. The criterion is used to select an optimal set of control device parameter values, which control each device’s operating modes and transitions between these modes and affect the excitation of the frame vibration due to possible shocks in the system. The criterion is formulated based on the vibration displacement processing from these dynamic measurements, the modified Goodman and Palmgren-Miner rules, and the results of static computational analyse. This criterion compares the effect of damage to the modes that control these sets of parameters, while the selection of the optimal control set is performed. At the end of the article, the limitations resulting from the simplifications used are described. The application of this procedure is also useful, for example, when further data are obtained by subsequent experimental stress-strain analysis methods and when we want to reduce the number of possible operating modes by which we carry out subsequent measurements among the most damaging modes.
EN
The safety, comfort of the crews, stability, economics of the equipment when ship operating is the leading requirement in the field of designing and manufacturing marine structure and machinery. As a result, all parts of the ships must be tested and inspected to meet the basic safety requirements of the shipping association. The design, manufacture, testing in the maritime field in general and shipbuilding sector in particular are expensive, time consuming: such as aerodynamic experiments of the engine, collision test, ship manoeuvring, vibration test and balance of deck beams, hull beams, hatch covers, shafts ...thus experimental works are sometimes impossible. Along with the development of computer science, many numerical models and software programs have been developed to solve these difficult problems. There are many numerical modelling methods, starting with the finite difference method, the boundary element method, the finite element method, the no mesh method, the weight residue or the energy method. The Work will be limited to the analysis of the most popular numerical modelling method - finite element method using Patran and Nastran software. In the first step of our research, T-beam was analysed as a part of ship hull structure (thin-walled structure). The article goes into the analysis of the accuracy of selected numerical models for the natural vibration frequency of the T-beams mounted on the plate. After modelling, calculating the natural frequency of the T-beam using the Patran - Nastran software, the results were compared with the theoretical values. From that, we evaluate the dispersion and error of different numerical models and select the optimal numerical model. Optimal model will be used for modelling full ship hull with superstructure.
EN
Mathematical models of vehicle wheel with metal scales are introduced in this article. When analysing the interaction between vehicle wheel with a metal scale and rail in the system “Vehicle – Track”, the changes of the kinematic and dynamic parameters of the wheel and rail contact points in time are examined, depending on the height of the 2 mm metal scale, when the length of the metal scale is 100 mm and the speed of movement is V = 40 - 100 km/h. The results obtained after the research of the system “Vehicle – Track”, when the wheel has a metal scale, help to better understand and evaluate the impact of metal scale on wheel on dynamic loads of rail and vehicle and the regularities of their movement. The appearance of a metal scale on the wheel’s surface causes technical and maintenances problems for the rolling stock. Railway standards limit the speed of movement that depends on a certain size of metal scale.
PL
W niniejszym artykule przedstawiono modele matematyczne koła pojazdu szynowego z powstałą w wyniku zużycia metalową łuską. Analizując oddziaływania pomiędzy kołem pojazdu z łuską a szyną w układzie "pojazd–tor", badano zmiany kinematycznych i dynamicznych parametrów punktów kontaktu koła z szyną zachodzące w czasie, w zależności od wysokości metalowej łuski (2mm), przy długości łuski 100 mm i zakresie prędkości ruchu pojazdu V = 40–100 km/h. Wyniki uzyskane w badaniu układu "pojazd–tor" dla kół na powierzchni których powstała metalowa łuska, umożliwiają lepsze zrozumienie oraz ocenę wpływu łuski na dynamiczne obciążenia szyny i pojazdu oraz prawidłowości ruchu pojazdu. Pojawienie się metalowej łuski na powierzchni koła powoduje problemy techniczne i obsługowe w utrzymaniu ruchu taboru kolejowego. Normy kolejowe ograniczają prędkość ruchu pojazdów szynowych, uzależniając ją od rozmiaru łuski.
EN
A finite element model based upon the density functional theory is developed to investigate the vibrational characteristics of armchair phosphorene nanotubes. To this end, the PP bonds are simulated by beam elements whose elastic properties are obtained from the analogy of molecular and structural mechanics. The effects of nanotube length, diameter and boundary conditions on the frequencies of armchair phosphorene nanotubes are evaluated. It is shown that the effect of nanotube radius on its natural frequency is weakened by increasing the nanotube aspect ratio. Comparing the first ten frequencies of armchair phosphorene nanotubes with different diameters, it is observed that the effect of diameter on the vibrational behavior of phosphorene nanotubes is more pronounced at higher modes.
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