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    Tytuł:
    Vibrating moistening of wheat grain
    Autorzy:
    Chornyi, Valentyn
    Kharchenko, Yevgen
    Powiązania:
    https://bibliotekanauki.pl/articles/24201995.pdf
    Data publikacji:
    2023
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    wheat
    moisture
    amplitude
    frequency
    vibration
    pszenica
    wilgoć
    amplituda
    częstotliwość
    drgania
    Opis:
    The article experimentally established the influence of amplitude, frequency and duration of processing on the efficiency of vibratory wetting of wheat. With increasing amplitude and frequency of oscillations, as well as the duration of processing, the increase in moisture in the grain increases nonlinearly. With oscillation amplitudes of 10 and 20 mm and constant frequency of 10 Hz and processing duration of 8 min., Wheat grain increased moisture by 2.1%. Processing time more than 8 min. does not increase the moisture content of wheat. The largest increase in moisture in wheat was observed at an oscillation frequency of 12 Hz and an amplitude of 20 mm and a treatment duration of 5 min. Increasing the oscillation frequency more than 12 Hz did not lead to an increase in wheat moisture. It was found that the load does not affect the efficiency of moistening wheat grain.
    Źródło:
    Vibrations in Physical Systems; 2023, 34, 1; art. no. 2023113
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical, experimental and fuzzy logic applications for investigation of crack location and crack depth estimation in a free-free aluminum beam
    Autorzy:
    Behera, S. K.
    Parhi, D. R.
    Das, H. C.
    Powiązania:
    https://bibliotekanauki.pl/articles/127769.pdf
    Data publikacji:
    2018
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    crack
    natural frequency
    mode shapes
    numerical
    fuzzy
    pęknięcie
    częstotliwość drgań własnych
    kształty modów
    Opis:
    A beam structure under natural vibration in presence of crack undergoes a sharp change in its dynamic characteristics. In the present study the changes in two important modal vibration parameters like mode shapes and natural frequencies have been extensively studied for crack diagnosis in presence and absence of crack. Numerical and experimental investigations have been carried out using an aluminium Free-Free beam structure with and without crack. The crack presence is indicative of a decrease in local flexibility at crack location and a variation in mode shapes and natural frequencies are noticed. These variations in modal parameters have been used as the tools for crack diagnosis. In the present paper, efforts are made to analyse the presence of a crack using the application of fuzzy logic methodology. Here relative natural frequencies preferably first three are derived from experimental and theoretical investigations are utilised as input data to the fuzzy controller with Gaussian membership functions to obtain crack position and crack depth as output data. The resulted output data from fuzzy logic and the result from corresponding experimental and numerical analysis have been compared.The deviation of result of fuzzy logic from numerical and experimental results have been found to be within a limit of 3%.
    Źródło:
    Vibrations in Physical Systems; 2018, 29; 1-20
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Detection of structural damage of technical objects with the use of multidimensional analysis
    Autorzy:
    Mikołajczak, Paweł
    Mikołajczak, Jan
    Werzbicki, Sławomir
    Powiązania:
    https://bibliotekanauki.pl/articles/2146614.pdf
    Data publikacji:
    2021
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    multidimensional analysis
    vibration
    wheel rim
    resonant frequency
    analiza wielowymiarowa
    drgania
    wieniec koła
    częstotliwość rezonansowa
    Opis:
    The paper presents a damage identification method of technical objects with the use of multidimensional analyses. The studied objects were rolling bearings tested on a laboratory test stand as well as vehicle wheel rims. The rims were examined by an Automated Tester. A group of variables describing the condition of the bearings included basic parameters of acceleration signal such as: RMS, peak value, functions describing the envelope of vibration spectrum and additionally the experimental coefficient of friction for the oscillatory motion. Diagnostic measurements data can be input into the proposed mathematical models and compared with a database of cases of the object technical states. Results of the multidimensional analysis of diagnostic parameters are presented in the form of diagrams (cluster trees). On this basis, the technical condition of the tested object can be easily interpreted. The proposed models supported the classification of wheel rims into groups characterized by similar frequencies and amplitude based on shock tests.
    Źródło:
    Vibrations in Physical Systems; 2021, 32, 2; art. no. 2021211
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Free flexural vibrations of an expanded-tapered sandwich beam
    Autorzy:
    Magnucki, Krzysztof
    Kustosz, Joanna
    Goliwąs, Damian
    Powiązania:
    https://bibliotekanauki.pl/articles/24201991.pdf
    Data publikacji:
    2023
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    analytical modelling
    expanded-tapered sandwich beam
    fundamental natural frequency
    modelowanie analityczne
    belka sandwiczowa
    częstotliwość drgań własnych
    Opis:
    The paper is devoted to the analytical modelling of a simply supported expanded-tapered sandwich beam. The simplified analytical model of this beam with omitting the shear effect is elaborated. Based on Hamilton’s principle, the differential equation of motion of this beam is obtained. This equation is analytically solved with consideration of the deflection line of this beam subjected to its own weight. The fundamental natural frequencies for exemplary beams are derived. Moreover, the FEM model of the beam in the ABAQUS is developed. The calculation results of the fundamental natural frequency of exemplary beams of these two methods are presented in tables and figures.
    Źródło:
    Vibrations in Physical Systems; 2023, 34, 1; art. no. 2023114
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Free vibrations of geometrically nonlinear column locally resting on the winkler elastic foundation under the specific load
    Autorzy:
    Szmidla, J.
    Cieślińska-Gąsior, I.
    Powiązania:
    https://bibliotekanauki.pl/articles/128264.pdf
    Data publikacji:
    2016
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    frequency of free vibrations
    Winkler elastic foundation
    slender systems
    częstotliwość drgań własnych
    sprężyste podłoże Winklera
    układy smukłe
    Opis:
    The results of theoretical and numerical studies concerning continuous system subjected to the follower force directed towards the positive pole, locally resting on Winkler elastic foundation are presented in this paper. The load by follower force directed towards the positive pole is guaranteed by loading structure built of loading and receiving heads made of elements of circular outlines. Abovementioned heads are real constructions, used in experimental research of continuous systems. Taking into account total mechanical energy of the system, the Hamilton’s principle and the small parameter method, the differential equations of motion and boundary conditions of the considered column were determined. On the basis of a solution of the issue of dynamics of the system, an appropriate formulas were formulated and then the trajectory of curves on the plane frequency of free vibrations – the value of external load were calculated taking into considerations physical and geometrical parameters of the structure, including parameter of loading head and parameters describing Winkler elastic foundation.
    Źródło:
    Vibrations in Physical Systems; 2016, 27; 355-362
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Experimental research of the AMWG algorithm for assessing amplitude modulation in wind turbine noise
    Autorzy:
    Czapla, Marcjanna
    Wszołek, Tadeusz
    Powiązania:
    https://bibliotekanauki.pl/articles/24202008.pdf
    Data publikacji:
    2022
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    wind turbine noise
    amplitude modulation
    modulation depth
    modulation frequency
    hałas turbin wiatrowych
    modulacja amplitudy
    głębokość modulacji
    częstotliwość modulacji
    Opis:
    The operation of a wind turbine (WT) is characterized by fluctuations in sound pressure amplitude associated with the passage of the propeller blade through the tower. Amplitude Modulation (AM) is one of the factors that contributes to the increased annoyance of wind turbine noise. The phenomenon of AM is currently the subject of research in many research centers around the world in the context of a parametric assessment of its impact on annoyance. Despite the development of many methods to measure the AM of a WT noise, there is no commonly accepted method. This paper discusses the most crucial factors that stimulate the phenomenon of AM and the implementation in the MATLAB environment of the algorithm to find the frequency and depth of AM proposed by the Amplitude Modulation Working Group (AMWG). The results of verification of the developed algorithm as well as the measurement results of the frequency and depth of modulation for two measurement samples of a 2 MW wind turbine are presented.
    Źródło:
    Vibrations in Physical Systems; 2022, 33, 3; art. no. 2022317
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Natural frequencies of layered elongated cylindrical panels for geometrically nonlinear deformation at discrete consideration of components
    Autorzy:
    Marchuk, M.
    Goriachko, T.
    Pakosh, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/128246.pdf
    Data publikacji:
    2016
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    elongated layered panel
    nonlinear vibrations
    perturbation method
    natural frequencies
    panele podłużne
    drgania nieliniowe
    metoda perturbacji
    częstotliwość drgań własnych
    Opis:
    The proposed and verified the technique of finding a finite number of first natural frequencies for geometrically nonlinear vibrations of layered elongated cylindrical panels at discrete consideration of components. The influence of the radius of curvature on the natural frequencies of three- and five-layered panels is investigated. The dependence between the volume of filler three-layer panels and the lowest natural frequency has been established.
    Źródło:
    Vibrations in Physical Systems; 2016, 27; 255-264
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dynamic analysis of optimized two-phase auxetic structure
    Autorzy:
    Idczak, E.
    Stręk, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/127856.pdf
    Data publikacji:
    2017
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    negative Poisson's ratio
    auxetics
    eigenfrequency
    topology optimization
    dynamic analysis
    ujemny współczynnik Poissona
    auksetyki
    częstotliwość drgań własnych
    optymalizacja topologiczna
    analiza dynamiczna
    Opis:
    This paper presents a dynamic analysis of earlier optimized auxetic structure. This optimization based on the distribution of two materials in such way to obtain a minimal value of Poisson’s ratio (PR), which indicates the auxetic properties. The initial optimized shape was so-called star structure, which if is made from one material has the PR close to 0.188. After optimization with the goal function of PR-minimization, the obtained value was equal to -9.5043. Then the eigenfrequencies for the optimized structure were investigated. The calculations were carried out by means of Finite Element Method (FEM). For optimization of the value of Poisson’s ratio was used algorithm MMA (Method of Moving Asymptotes). The computing of single material properties (PR, Young’s modulus, density) for the whole shape was made by means of SIMP method (Solid Isotropic Method with Penalization).
    Źródło:
    Vibrations in Physical Systems; 2017, 28; 1-12
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Paradigm for natural frequency of an un-cracked simply supported beam and its application to single-edged and multi-edged cracked beam
    Autorzy:
    Khalkar, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/128309.pdf
    Data publikacji:
    2018
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    paradigm
    natural frequency
    simply supported beam
    ANSYS
    modal analysis
    zero frequency deflection
    condition monitoring
    paradygmat
    częstotliwość drgań własnych
    belka swobodnie podparta
    analiza modalna
    ugięcie zerowe
    monitorowanie stanu technicznego
    Opis:
    In this research paper, a theoretical method of analysis of the first natural frequency of an un-cracked simply supported beam in bending mode is presented. The formula of a paradigm is used to determine the natural frequency of an un-cracked beam. The converged natural frequency formula of a paradigm is then extended to a single edged and multi-edged cracked simply supported beam to evaluate their natural frequency. The main attraction of the proposed method is that it gives one more significant way to the researchers to determine the natural frequency of cracked beams. The limited fatigue strength, defects like corrosion, corrosion-erosion, and corrosion fatigue in the beam are the main causes of formation of edged cracks in beams. Hence the evaluation of natural frequency of cracked beams and its use in the inverse problem is of utmost importance to do the condition monitoring of the structures by the vibration methods.
    Źródło:
    Vibrations in Physical Systems; 2018, 29; 1-12
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Free vibrations of the partially tensioned geometrically non-linear system subjected to Euler’s load
    Autorzy:
    Uzny, S.
    Sokół, K.
    Osadnik, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/127651.pdf
    Data publikacji:
    2016
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    column
    Bernoulli-Euler's theory
    free vibration frequency
    nonlinear system
    characteristic curves
    amplitude of vibration
    nonlinear component of free vibrations frequency
    kolumna
    teoria Eulera-Bernoulliego
    częstotliwość drgań własnych
    układ nieliniowy
    krzywe charakterystyczne
    amplituda drgań
    nieliniowa składowa częstości drgań własnych
    Opis:
    In this study the fixed-fixed column subjected to axial Euler’s load has been investigated. The load is placed between the fixed ends of the structure and its location can be changed along column’s length. The boundary problem of free vibrations of the mentioned system has been formulated on the basis of Bernoulli – Euler theory and taking into account non-linear axial deformation relationship. Due to non-linear expressions the solution of the problem was done with small parameter method. In the paper the change of the first vibration frequency in relation to location and magnitude of the loading force was obtained. The relationship between natural vibration frequency and the amplitude is also discussed.
    Źródło:
    Vibrations in Physical Systems; 2016, 27; 399-406
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-10 z 10

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