Temat: nieliniowe drgania - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: A discrete model for geometrically nonlinear free and forced vibrations of stepped and continuously segmented Euler-Bernoulli AFG beams (SAFGB) carrying point masses
Autorzy:: Moukhliss, Anass
Rahmouni, Abdellatif
Bouksour, Othman
Benamar, Rhali
Powiązania:: https://bibliotekanauki.pl/articles/2146732.pdf
Data publikacji:: 2022
Wydawca:: Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:: discrete model
stepped beam
free non-linear vibration
forced nonlinear vibration
AFG beam
point mass
model dyskretny
belka o skokowo zmiennym przekroju
drgania swobodne
drgania wymuszone
drgania nieliniowe
Opis:: A discrete model is applied to handle the geometrically nonlinear free and forced vibrations of beams consisting of several different segments whose mechanical characteristics vary in the length direction and contain multiple point masses located at different positions. The beam is presented by an N degree of freedom system (N-Dof). An approach based on Hamilton's principle and spectral analysis is applied, leading to a nonlinear algebraic system. A change of basis from the displacement basis to the modal basis has been performed. The mechanical behavior of the N-Dof system is described in terms of the mass tensor mij, the linear stiffness tensor kij, and the nonlinear stiffness tensor bijkl. The nonlinear vibration frequencies as functions of the amplitude of the associated vibrations in the free and forced cases are predicted using the single mode approach. Once the formulation is established, several applications are considered in this study. Different parameters control the frequency-amplitude dependence curve: the laws that describe the variation of the mechanical properties along the beam length, the number of added masses, the magnitude of excitation force, and so on. Comparisons are made to show the reliability and applicability of this model to non-uniform and non-homogeneous beams in free and forced cases.
Źródło:: Diagnostyka; 2022, 23, 4; art no 2022401
1641-6414
2449-5220
Pojawia się w:: Diagnostyka
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Experimental investigation for non-linear vibrations of free supported and cantilever FFF rectangular plates
Autorzy:: Abdeddine, E.
Majid, A.
Beidouri, Z.
Zarbane, Kh.
Powiązania:: https://bibliotekanauki.pl/articles/24200580.pdf
Data publikacji:: 2022
Wydawca:: Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:: fused filament
nonlinear dynamic behaviour
nonlinear transverse vibrations
nieliniowe zachowanie dynamiczne
nieliniowe drgania poprzeczne
Opis:: Purpose: The aim of this paper is to investigate experimentally the effect of large vibration of a cantilever and a fully free rectangular plate made by a Fused Filament Fabrication process. Furthermore, this investigation attempts to compare our measurements and those obtained in the literature experimentally. Design/methodology/approach: For this purpose, a test rig was designed and manufactured for all experimental trials. The plate was excited randomly and harmonically at large displacement respectively, to obtain the linear and non-linear frequencies parameter. Findings: The non-linear dynamic behaviour of our structure at forced vibration is figured by exciting the plate at large displacement. The dependence of frequency and amplitude vibration are examined for the first, second, and third mode shapes. The non-linear dynamic behaviour of cantilever plates is compared with literature to illustrate the convergence of our results by using our specific mechanical properties, printing parameters, and process. Furthermore, the non-dimensional comparison is shown by 33.38%, 5.83%, and 20.58% for the first, second, and third mode shapes, respectively. Research limitations/implications: Experimental tests will be performed on a 3D-printed metal plate to improve the present work. Practical implications: This work is intended to determine the dynamic proprieties of our parts in order to manufacture a safe and comfort machine. Originality/value: Actually, the dynamic behaviour of our 3D printing plates is compared with the obtained in the case of the isotropic plate for the aim to predict the convergence of both structures.
Źródło:: Archives of Materials Science and Engineering; 2022, 116, 2; 49--56
1897-2764
Pojawia się w:: Archives of Materials Science and Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Finite element model for analysis of characteristics of shrouded rotor blade vibrations
Model elementów skończonych do analizy charakterystyk drgań łopat wirnika osłoniętego
Autorzy:: Zinkovskii, Anatoliy
Savchenko, Kyrylo
Onyshchenko, Yevheniia
Polishchuk, Leonid
Nazerke, Abilkaiyr
Zhumazhanov, Bagashar
Powiązania:: https://bibliotekanauki.pl/articles/2174719.pdf
Data publikacji:: 2022
Wydawca:: Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:: FE modeling
modal analysis
forced vibration analysis
shrouded blade
nonlinear vibrations
modelowanie MES
analiza modalna
analiza drgań wymuszonych
łopata osłonięta
drgania nieliniowe
Opis:: The paper presents the approaches to FE modelling of blade airfoil, contact between the shrouds and operational damage. The regularities are established concerning the influence of the finite element type, finite element mesh and model of contact interaction on the spectrum of natural frequencies of blade assemblies. The use of the developed computational models is substantiated to determine the forced vibration characteristics of the selected objects of investigation. Based on the performed numerical experiments it was substantiated of finite element model selection for analysis of characteristics of shrouded rotor blade vibrations.
W artykule przedstawiono podejścia do modelowania elementów skończonych płata łopaty, styku osłon oraz uszkodzeń eksploatacyjnych. Ustalono prawidłowości dotyczące wpływu typu elementu skończonego, siatki elementów skończonych oraz modelu interakcji stykowej na widmo częstotliwości drgań własnych zespołów łopatek. Uzasadnione jest wykorzystanie opracowanych modeli obliczeniowych do wyznaczania charakterystyk drgań wymuszonych wybranych obiektów badań. Na podstawie przeprowadzonych eksperymentów numerycznych uzasadniono wybór modelu elementów skończonych do analizy charakterystyk drgań osłoniętych łopat wirnika.
Źródło:: Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska; 2022, 12, 4; 11--16
2083-0157
2391-6761
Pojawia się w:: Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Numerical investigation of geometrically nonlinear clamped uniform rods and rods with sections varying exponentially free vibration
Autorzy:: Abdeddine, E.
Majid, A.
Bouzida, N.
Bouzida, Z.
Zarbane, Kh.
Powiązania:: https://bibliotekanauki.pl/articles/2201031.pdf
Data publikacji:: 2022
Wydawca:: Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:: non-linear longitudinal vibration
Lagrange equations
harmonic balance method
linearized approach
drgania nieliniowe
drgania podłużne
równania Lagrange'a
metoda bilansu harmonicznych
podejście linearne
Opis:: Purpose: The present paper is intended to investigate the problem of linear and non-linear longitudinal free vibration of uniform rods and rods whose cross-sections vary exponentially at large vibration amplitudes. Design/methodology/approach: The method adopted consists in discretizing the energy term on linear kij and non-linear rigidity tensor bijkl, as well as the mass tensor mij. Therefore, the formulation of this structure is based on Lagrange equations and the harmonic balance method so as to obtain the nonlinear algebraic equations. These latter are solved numerically and analytically through the explicit and linearized method. Findings: The response of Clamped-Clamped uniform and non-uniform rods on our structure are highlighted in the amplitude frequency and associated first three mode shapes. Moreover, this research leads to study the influence of the exponential slope on the maximum displacement, thus emphasizing the non-uniform bars usefulness. The obtained results are then compared with the available literature with a view to validating this theory. Research limitations/implications: As a perspective, the method used in this paper would be pushed to study the FDM material, taking into account other parameters related to additive manufacturing, and later to be validated experimentally. Practical implications: Longitudinal vibrations are important in mechanical structures; therefore, the determination of their dynamic behaviour needs to be understood. In the present study, the effect of the displacement amplitude on the exponential slope of the structure was analysed, which led to the determination of the reduction range of the vibration amplitude under resonance. However, this should be taken into account in the design process. Besides, the usefulness of the non-linearity geometric effects was demonstrated to examine these structures by considering all the parameters involved. Originality/value: A linearized procedure is used to solve a nonlinear algebra equation. The use of this method leads to reduce calculation time contrary to iterative methods.
Źródło:: Journal of Achievements in Materials and Manufacturing Engineering; 2022, 112, 2; 49--63
1734-8412
Pojawia się w:: Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: The effect of added point masses on the geometrically non-linear vibrations of SCSC rectangular plates
Autorzy:: Hamdani, Mustapha
El Kadiri, Mounia
Benamar, Rhali
Powiązania:: https://bibliotekanauki.pl/articles/2096183.pdf
Data publikacji:: 2022
Wydawca:: Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:: SCSC rectangular plates
added mass
nonlinear free vibration
nonlinear forced vibration
swobodne drgania nieliniowe
płyta prostokątna
nieliniowe drgania wymuszone
Opis:: A point mass added to a plate may have a significant effect on its linear and nonlinear dynamics, including frequencies, mode shapes and the forced response to external loading. In the present paper, a simply supported clamped simply supported clamped rectangular plate (SCSCRP) carrying a point mass is examined. The expressions for the kinetic, linear and non-linear strain energies are derived by taking into account the effect of the added mass on the kinetic energy and the effect of the membrane forces induced by the non-linearity on the strain energy. The discretization of these expressions makes the mass tensor, the linear and non-linear rigidity tensors appear in a non-linear algebraic multimode amplitude equation, the iterative solution of which permit to obtain, in the neighborhood of the first non-linear mode, the basic SCSCRP function amplitude dependent contribution coefficients. Nonlinear frequency response functions have been obtained for the first time, based on an iterative numerical solution in each case of the associated complete set of nonlinear algebraic equations. Such new results are useful for a better qualitative understanding allowing an optimal dynamic design of the rectangular plates with added masses.
Źródło:: Diagnostyka; 2022, 23, 2; art. no. 2022206
1641-6414
2449-5220
Pojawia się w:: Diagnostyka
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Analysis of the associated stress distributions to the nonlinear forced vibrations of functionally graded multi-cracked beams
Autorzy:: Chajdi, Mohcine
Adri, Ahmed
El Bikri, Khalid
Benamar, Rhali
Powiązania:: https://bibliotekanauki.pl/articles/1840885.pdf
Data publikacji:: 2021
Wydawca:: Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:: nonlinear vibration
multi-crack
functionally graded beams
forced vibrations
drgania nieliniowe
belki gradientowe
rozkład naprężeń
drgania wymuszone
Opis:: Geometrically non-linear vibrations of functionally graded Euler-Bernoulli beams with multi-cracks, subjected to a harmonic distributed force, are examined in this paper using a theoretical model based on Hamilton's principle and spectral analysis. The homogenisation procedure is performed, based on the neutral surface approach, and reduces the FG beams analysis to that of an equivalent homogeneous multi-cracked beam. The so-called multidimensional Duffing equation obtained and solved using a simplified method (second formulation) previously applied to various non-linear structural vibration problems. The curvature distributions associated to the multi-cracked beam forced deflection shapes are obtained for each value of the excitation level and frequency. The parametric study performed in the case of a beam and the detailed numerical results are given in hand to demonstrate the effectiveness of the proposed procedure, and in the other hand conducted to analyse many effects such as the beam material property, the presence of crack, the vibration amplitudes and the applied harmonic force on the non-linear dynamic behaviour of FG beams.
Źródło:: Diagnostyka; 2021, 22, 1; 101-112
1641-6414
2449-5220
Pojawia się w:: Diagnostyka
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Mathematical model and method of determination of amplitude-frequency characteristics of corrugated cylindrical shells for geometrically nonlinear vibrations
Autorzy:: Marchuk, Mykhailo
Goriachko, Taras
Kindratskyy, Bohdan
Pakosh, Vira
Powiązania:: https://bibliotekanauki.pl/articles/2146612.pdf
Data publikacji:: 2020
Wydawca:: Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:: corrugated shell
geometrically nonlinear vibrations
mathematical model
generalized method of perturbations
amplitude-frequency characteristics
powłoka falista
drgania geometrycznie nieliniowe
model matematyczny
uogólniona metoda perturbacji
charakterystyka amplitudowo-częstotliwościowa
Opis:: On the basis of spatial geometrically nonlinear theory of elasticity by using quadratic approximations for components of the vector of displacements along the normal coordinate to the median surface is developed a new mathematical model of nonlinear dynamics of cylindrical shells with corrugated configuration for median surface. The perturbation method for the solution of systems of nonlinear differential equations for problems of determination of amplitude-frequency characteristics is generalized. In a combination of finite element and generalized perturbations methods, a new methodology for solving problems of free geometrically nonlinear vibrations of shells with complex guide geometry was developed and verified. With its help the influence of geometrical parameters of corrugating at circular coordinate on the main frequency of the elongated cylindrical panel is investigated.
Źródło:: Vibrations in Physical Systems; 2020, 31, 3; art. no. 2020316
0860-6897
Pojawia się w:: Vibrations in Physical Systems
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Linear and geometrically nonlinear free and forced vibrations of multi-cracked beams
Autorzy:: Chajdi, Mohcine
Adri, Ahmed
El Bikri, Khalid
Benamar, Rhali
Powiązania:: https://bibliotekanauki.pl/articles/329328.pdf
Data publikacji:: 2019
Wydawca:: Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:: nonlinear vibrations
multi-crack
Euler-Bernoulli beams
free vibrations
forced vibrations
drgania nieliniowe
drgania własne
drgania wymuszone
teoria Bernoulliego-Eulera
Opis:: The linear and geometrically nonlinear free and forced vibrations of Euler-Bernoulli beams with multicracks are investigated using the crack equivalent rotational spring model and the beam transfer matrix method. The Newton Raphson solution of the transcendental frequency equation corresponding to the linear case leads to the cracked beam linear frequencies and mode shapes. Considering the nonlinear case, the beam transverse displacement is expanded as a series of the linear modes calculated before. Using the discretised expressions for the total strain and kinetic energies and Hamilton’s principle, the nonlinear amplitude equation is obtained and solved using the so-called second formulation, developed previously for similar nonlinear structural dynamic problems, to obtain the multi-cracked beam backbone curves and the corresponding amplitude dependent nonlinear mode shapes. Considering the forced vibration case, the nonlinear frequency response functions obtained numerically near to the fundamental nonlinear mode using a single mode approach show the effects of the number of cracks, their locations and depths, and the level of the concentric harmonic force. The inverse problem is explored using the frequency contour plot method to identify crack parameters, such as the crack locations and depths. Satisfactory comparisons are made with previous analytical results.
Źródło:: Diagnostyka; 2019, 20, 1; 111-125
1641-6414
2449-5220
Pojawia się w:: Diagnostyka
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Nonlinear vibrations of the partially tensioned system taking into account the asymmetry of the stiffness of supports
Autorzy:: Uzny, Sebastian
Osadnik, Michał
Powiązania:: https://bibliotekanauki.pl/articles/128293.pdf
Data publikacji:: 2019
Wydawca:: Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:: slender nonlinear systems
free vibrations
Euler’s load
nieliniowe układy smukłe
drgania swobodne
obciążenie Eulera
Opis:: The nonlinear vibrations of the partially tensioned slender column are presented in this paper. The considered system is subjected to Euler’s load, which direction of action is consistent with the non-deformed axis of the column. The magnitude of the external load is variable and its application point is located at different heights between the upper and lower supports. In addition, the longitudinal displacement and rotation of both of the system ends are limited by the discrete elements in the form of translational and rotational springs. This nonlinear system is based on the screw drive used in the vertical lift platform for disabled people or cargo lift equipped with an engine room located in the lower part of the frame. The boundary problem of free vibrations of the mentioned system has been formulated on the basis of Bernoulli - Euler theory and due to nonlinear expressions the solution of the problem was conducted with small parameter method. The results of numerical simulations are concern on linear and nonlinear component of vibrations in relation to the location of external load application and influence of asymmetric value of supports stiffness on the free vibration frequency.
Źródło:: Vibrations in Physical Systems; 2019, 30, 2; 1-8
0860-6897
Pojawia się w:: Vibrations in Physical Systems
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Nonlinear dynamic phenomena in fixed and rotating mechanical structures
Autorzy:: Warmiński, J.
Powiązania:: https://bibliotekanauki.pl/articles/127654.pdf
Data publikacji:: 2018
Wydawca:: Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:: nonlinear vibrations
rotating structures
resonance
saturation control
composite beams
drgania nieliniowe
struktury wirujące
rezonans
kontrola saturacji
belka kompozytowa
Opis:: A review of selected nonlinear phenomena which may occur in fixed or rotating structures has been presented in the paper. At first, a self, parametrically and externally exited oscillator with added time delay control has been studied. It has been shown that the interaction between different vibration types may produce an untypical resonance curve, with five solutions occurring, observed by an internal resonance loop. The existence of the loop may be controlled by adding a time delay input signal. A proper selection of the time delay may reduce the loop or eliminate it totally. In the second problem a rotating hub-beam structure has been studied. The blade, apart from passive layers, has been composed of two active PZT layers which enabled active vibration control. A nonlinear coupling of the structure (plant) and the controller resulted in the so called saturation phenomenon which has been effectively used for the vibration reduction.
Źródło:: Vibrations in Physical Systems; 2018, 29; 1-6
0860-6897
Pojawia się w:: Vibrations in Physical Systems
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 11.

Tytuł:: Tolerance modelling of nonstationary problems of microheterogeneous media and structures
Autorzy:: Jędrysiak, J.
Domagalski, Ł.
Marczak, J.
Pazera, E.
Powiązania:: https://bibliotekanauki.pl/articles/128176.pdf
Data publikacji:: 2018
Wydawca:: Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:: microheterogeneous media
microheterogeneous structure
tolerance modelling
non-stationary problems
nonlinear vibrations
microstructure effect
ośrodki mikroheterogeniczne
struktury mikroheterogeniczne
modelowanie tolerancyjne
problemy niestacjonarne
drgania nieliniowe
efekt mikrostruktury
Opis:: In this note a certain review of applications of a non-asymptotic modelling approach, called the tolerance modelling, is presented. Some objects and thermomechanical problems are shown, with a general outline of this method and an example of application for nonlinear vibrations of periodic beams.
Źródło:: Vibrations in Physical Systems; 2018, 29; 1-23
0860-6897
Pojawia się w:: Vibrations in Physical Systems
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 12.

Tytuł:: A discrete model for nonlinear vibrations of a simply supported cracked beams resting on elastic foundations
Autorzy:: Khnaijar, A.
Benamar, R.
Powiązania:: https://bibliotekanauki.pl/articles/328710.pdf
Data publikacji:: 2017
Wydawca:: Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:: nonlinear
discrete
beam
Winkler foundation
crack
vibration
drgania nieliniowe
podłoże Winklera
belka
pęknięcie
model
Opis:: The present paper introduces a discrete physical model to approach the problem of nonlinear vibrations of cracked beams resting on elastic foundations. It consists of a beam made of several small bars, evenly spaced, connected by spiral springs, presenting the beam bending stiffness. The crack is modeled by a spiral spring with a reduced stiffness and the Winkler soil stiffness is modeled using linear vertical springs. Concentrated masses, presenting the inertia of the beam, are located at the bar ends. The nonlinear effect, due to the axial forces in the bars resulting from the change in their length, is presented by longitudinal springs. This model has the advantage of simplifying parametric studies, because of its discrete nature, allowing any modification in the mass and the stiffness matrices, and in the nonlinearity tensor, to be made separately. After establishing the model, various practical applications are performed without the need of going through all the formulation again. Numerical linear and nonlinear results are given, corresponding to a cracked simply supported beam.
Źródło:: Diagnostyka; 2017, 18, 3; 39-46
1641-6414
2449-5220
Pojawia się w:: Diagnostyka
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 13.

Tytuł:: Analiza drgań wieszara cięgnowego jako modelu kolejowej sieci trakcyjnej obciążonej ruchem pantografów
Vibration analysis of suspended cable structure as a model of railway overhead wire system subjected to moving pantographs
Autorzy:: Bryja, D.
Popiołek, A.
Powiązania:: https://bibliotekanauki.pl/articles/104207.pdf
Data publikacji:: 2017
Wydawca:: Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:: symulacja drgań
drgania liniowe
drgania nieliniowe
siła nacisku
nacisk stykowy
drgania
przewód jezdny
tłumienie
vibration simulation
linear vibration
nonlinear vibration
contact force
wire vibration
damping influence
Opis:: Zwiększenie prędkości jazdy pociągów i rozwój kolei dużych prędkości spowodowały wyraźny wzrost zainteresowania problemami dynamiki kolejowych sieci trakcyjnych. W ostatnich latach pojawiło się w literaturze zagranicznej wiele nowych publikacji przedstawiających zaawansowane numerycznie metody symulacji drgań górnej sieci jezdnej i pantografów. W Polsce temat ten jest stosunkowo mało znany, stąd jednym z celów pracy jest przegląd literatury na temat metod modelowania sieci trakcyjnych. Celem zasadniczym jest przedstawienie oryginalnej metody symulacji drgań sprzężonego układu sieć trakcyjna – pantograf oraz zastosowanie metody do analizy drgań przykładowej sieci trakcyjnej. Metoda bazuje na modelu obliczeniowym przedstawionym przez autorów w odrębnej pracy, sformułowanym na podstawie teorii drgań wiotkiego cięgna z ciągłym rozkładem masy. Górna sieć jezdna jest traktowana jako wstępnie napięty, wieloprzęsłowy wieszar cięgnowy złożony z liny nośnej o niepomijalnym zwisie w przęsłach i przewodu jezdnego podwieszonego za pomocą wiotkich wieszaków nie przenoszących ściskania. Sieć trakcyjna jest obciążona dwoma pantografami poruszającymi się ze stałą prędkością. Pantografy są układami dynamicznymi o dwóch stopniach swobody. Równania ruchu wyprowadzone metodą Lagrange’a – Ritza zostały w tej pracy przekształcone poprzez wyodrębnienie nieliniowych sił, które kompensują wpływ wieszaków ściskanych. Opisano metodę rozwiązania nieliniowych równań ruchu i wyjaśniono sens fizyczny stowarzyszonych z nimi równań liniowych. Przedstawiono przykład symulacji drgań sieci złożonej z dziesięciu przęseł, świadczący o efektywności i możliwościach obliczeniowych prezentowanej metody oraz zbadano wpływ tłumienia w materiale liny nośnej i przewodu jezdnego na charakterystyki dynamiczne badanej sieci.
Increasing train speeds and rapid development of high speed railway systems give rice to growing interest in dynamics of railway overhead wire systems. In recent years, many new publications on advanced numerical methods for computer simulation of vibration of pantographcatenary systems appeared in foreign literature. In Poland, this topic is relatively unknown, hence one of the objectives of this paper is to review the literature on methods for modeling overhead contact lines and pantographs. The main goal is to present an original method for simulation of pantograph and catenary coupled system vibration and the use of method in dynamic analysis of a sample system. The method is based on the computational model which have been presented in a separate article. This model is formulated on the basis of vibration theory of a continuous cable. Catenary is treated as initially tensioned, multi-span cable structure which consists of a carrying cable characterized by non-negligible static sag and a contact wire suspended by means of droppers. The slackening of droppers under compressive forces is taken into account. Catenary is subjected to a passage of two pantographs moving with constant sped, each idealized as twodegree-of-freedom dynamic system. Equations of motion of the system, derived by the use of Lagrange equations and Ritz approximation of catenary displacements, are reexpressed in this paper to extract nonlinear forces which compensate the effects of compressed droppers. The method for solving nonlinear equations of motion is described. It is also explained what is a physical meaning of linear equations associated with these nonlinear. Exemplary simulations are presented for the catenary consisting of ten spans in order to demonstrate efficiency and computing capabilities of the simulation method. An influence of the material damping in carrying rope and this in contact wire, on the dynamic response of analyzed catenary is examined.
Źródło:: Czasopismo Inżynierii Lądowej, Środowiska i Architektury; 2017, 64, 2/I; 177-190
2300-5130
2300-8903
Pojawia się w:: Czasopismo Inżynierii Lądowej, Środowiska i Architektury
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 14.

Tytuł:: Linear and geometrically non-linear frequencies and mode shapes of beams carrying a point mass at various locations. An analytical approch and a parametric study
Autorzy:: Adri, A.
Benamar, R.
Powiązania:: https://bibliotekanauki.pl/articles/329670.pdf
Data publikacji:: 2017
Wydawca:: Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:: non-linear vibration
Hamilton’s principle
Newton-Raphson method
backbone curve
second formulation
drgania nieliniowe
zasada Hamiltona
metoda Newtona-Raphsona
analiza modalna
Opis:: In the present paper, the frequencies and mode shapes of a clamped beam carrying a point mass, located at different positions, are investigated analytically and a parametric study is performed. The dynamic equation is written at two intervals of the beam span with the appropriate end and continuity conditions. After the necessary algebraic transformations, the generalised transcendental frequency equation is solved iteratively using the Newton Raphson method. Once the corresponding program is implemented, investigations are made of the changes in the beam frequencies and mode shapes for many values of the mass and mass location. Numerical results and plots are given for the clamped beam first and second frequencies and mode shapes corresponding to various added mass positions. The effect of the geometrical non-linearity is then examined using a single mode approach in order to obtain the corresponding backbone curves giving the amplitude dependent non-linear frequencies.
Źródło:: Diagnostyka; 2017, 18, 2; 13-21
1641-6414
2449-5220
Pojawia się w:: Diagnostyka
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 15.

Tytuł:: Nonlinear Free Vibration Analysis of Micro-beams Resting on Viscoelastic Foundation Based on the Modified Couple Stress Theory
Autorzy:: Jam, J. E.
Noorabadi, M.
Namdaran, N.
Powiązania:: https://bibliotekanauki.pl/articles/139530.pdf
Data publikacji:: 2017
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: nonlinear free vibration
size dependence
modified couple stress theory
Euler-Bernoulli beam model
Galerkin method
swobodne drgania nieliniowe
zależność od wielkości
zmodyfikowana teoria naprężeń momentowych
model belki Eulera-Bernouliego
metoda Galerkina
Opis:: In this paper, nonlinear free vibration analysis of micro-beams resting on the viscoelastic foundation is investigated by the use of the modified couple stress theory, which is able to capture the size effects for structures in micron and sub-micron scales. To this aim, the governing equation of motion and the boundary conditions are derived using the Euler–Bernoulli beam and the Hamilton’s principle. The Galerkin method is employed to solve the governing nonlinear differential equation and obtain the frequency-amplitude algebraic equation. Finally, the effects of different parameters, such as the mode number, aspect ratio of length to height, the normalized length scale parameter and foundation parameters on the natural frequency-amplitude curves of doubly simply supported beams are studied.
Źródło:: Archive of Mechanical Engineering; 2017, LXIV, 2; 239-256
0004-0738
Pojawia się w:: Archive of Mechanical Engineering
Dostawca treści:: Biblioteka Nauki

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