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Tytuł:
Theoretical and experimental assessment of parameters for the non-linear viscoelastic model of structural pounding
Analityczne i eksperymentalne szacowanie wartości parametrów nieliniowego lepkosprężystego modelu zderzeń pomiędzy konstrukcjami budowlanymi
Autorzy:
Jankowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/281453.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
konstrukcje budowlane
trzęsienie ziemi
modele nieliniowe lepkosprężyste
structural pounding
earthquakes
non-linear viscoelastic model
Opis:
Impacts between adjacent structures during earthquakes have been recently intensively studied with the help of different models of the impact force. It has been verified through comparisons that the non-linear viscoelastic model is the most accurate one among them. One of the aims of the present paper is to derive a formula relating the impact damping ratio, as a parameter of the non-linear viscoelastic model, with a more widely used coefficient of restitution. Another aim is to determine the range of the coefficients of restitution and the impact stiffness parameters for different building materials, such as: steel, concrete, timber and ceramics, based on the results of an impact experiment. Both aims are new and original elements of the study in the field of earthquake-induced structural pounding. The results of the analysis show a wide range of the model parameters obtained for various prior-impact velocity and mass values. The use of these parametric values in numerical simulations allows us to study the behaviour of colliding structures with the increased accuracy.
Zjawisko zderzeń pomiędzy sąsiednimi konstrukcjami budowlanymi podczas trzęsień ziemi jest w ostatnim czasie intensywnie badane z wykorzystaniem różnych modeli numerycznych siły zderzenia w czasie kontaktu. Wyniki badań eksperymentalnych pokazują, iż nieliniowy model lepkosprężysty jest najdokładniejszy wśród modeli stosowanych do analizy. Model ten zdefiniowany jest poprzez dwa parametry: liczbę tłumienia zderzenia oraz parametr sztywności zderzenia. Jednym z celów niniejszego artykułu jest wyprowadzenie wzoru na zależność pomiędzy liczbą tłumienia zderzenia a współczynnikiem odbicia, który jest parametrem często stosowanym i opisywanym w literaturze. Kolejnym celem jest wyznaczenie zakresu wartości współczynników odbicia i parametrów sztywności zderzenia dla różnych materiałów budowlanych (stali, betonu, drewna i ceramiki) na podstawie wyników badań eksperymentalnych. Wyniki analizy pokazują szeroki zakres wartości parametrów nieliniowego modelu lepkosprężystego zderzeń otrzymanych dla różnych wartości prędkości zderzenia oraz masy testowanych elementów. Zastosowanie tych wartości w symulacjach numerycznych prowadzi do zwiększenia dokładności uzyskiwanych wyników w analizie zjawiska zderzeń pomiędzy konstrukcjami budowlanymi podczas trzęsień ziemi.
Źródło:
Journal of Theoretical and Applied Mechanics; 2007, 45, 4; 931-942
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of blood flow rheology using second-grade viscoelastic model (Phan-Thien–Tanner) within carotid artery
Autorzy:
Ramiar, A.
Larimi, M. M.
Ranjbar, A. A.
Powiązania:
https://bibliotekanauki.pl/articles/307522.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
tętnica szyjna
model lepkoplastyczny
przepływ pulsujący
naprężenie ścinające
OpenFOAM
carotid artery
viscoelastic model
pulsatile flow
shear stress
Opis:
Purpose: Hemodynamic factors, such as Wall Shear Stress (WSS), play a substantial role in arterial diseases. In the larger arteries, such as the carotid artery, interaction between the vessel wall and blood flow affects the distribution of hemodynamic factors. The fluid is considered to be non-Newtonian, whose flow is governed by the equation of a second-grade viscoelastic fluid and the effects of viscoelastic on blood flow in carotid artery is investigated. Methods: Pulsatile flow studies were carried out in a 3D model of carotid artery. The governing equations were solved using finite volume C++ based on open source code, OpenFOAM. To describe blood flow, conservation of mass and momentum, a constitutive relation of simplified Phan-Thien–Tanner (sPTT), and appropriate relations were used to explain shear thinning behavior. Results: The first recirculation was observed at t = 0.2 s, in deceleration phase. In the acceleration phase from t = 0.3 s to t = 0.5 s, vortex and recirculation sizes in bulb regions in both ECA and ICA gradually increased. As is observed in the line graphs based on extracted data from ICA, at t = 0.2 s, τyy is the maximum amount of wall shear stress and τxy the minimum one. The maximum shear stress occurred in the inner side of the main branch (inner side of ICA and ECA) because the velocity of blood flow in the inner side of the bulb region was maximum due to the created recirculation zone in the opposite side in this area. Conclusions: The rheology of blood flow and shear stress in various important parts (the area that are in higher rates of WSS such as bifurcation region and the regions after bulb areas in both branches, Line1–4 in Fig. 7) were also analyzed. The investigation of velocity stream line, velocity profile and shear stress in various sections of carotid artery showed that the maximum shear stress occurred in acceleration phase and in the bifurcation region between ECA and ICA which is due to velocity gradients and changes in thinning behavior of blood and increasing strain rate in Newtonian stress part.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 3; 27-41
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pattern of stress-strain accumulation due to a long dipslip fault movement in a viscoelastic layered model of the lithosphere–asthenosphere system
Autorzy:
Debnath, S. K.
Sen, S.
Powiązania:
https://bibliotekanauki.pl/articles/264497.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
trzęsienie ziemi
lepkosprężystość
aktywność sejsmiczna
aseismic period
dip-slip fault
earthquake prediction
stress accumulation
viscoelastic-layered model
Opis:
The process of stress accumulation near earthquake faults during the aseismic period in between two major seismic events in seismically active regions has become a subject of research during the last few decades. In the present paper a long dip -slip fault is taken to be situated in a viscoelastic layer over a viscoelastic half space representing the lithosphere-asthenosphere system. A movement of the dip-slip nature across the fault occurs when the accumulated stress due to various tectonic reasons, e.g., mantle convection etc., exceeds the local friction and cohesive forces across the fault. The movement is assumed to be slipping in nature, expressions for displacements, stresses and strains are obtained by solving the associated boundary value problem with the help of integral transformation and Green's function method. A detailed study of these expressions may give some ideas about the nature of stress accumulation in the system, which in turn will be helpful in formulating an earthquake prediction programme.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 3; 653-670
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Entropy analysis of third-grade MHD convection flows from a horizontal cylinder with slip
Autorzy:
Madhavi, K.
Prasad, V. R.
Gaffar, S. A.
Venkatadri, K.
Powiązania:
https://bibliotekanauki.pl/articles/139843.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
third-grade viscoelastic fluid model
thermal jump
entropy generation
Bejan number
Hartmann number
lepkosprężysty model cieczy trzeciego stopnia
skok termiczny
generowanie entropii
liczba Bejana
liczba Hartmanna
Opis:
In thermos fluid dynamics, free convection flows external to different geometries, such as cylinders, ellipses, spheres, curved walls, wavy plates, cones, etc., play major role in various industrial and process engineering systems. The thermal buoyancy force associated with natural convection flows can play a critical role in determining skin friction and heat transfer rates at the boundary. In thermal engineering, natural convection flows from cylindrical bodies has gained exceptional interest. In this article, we mathematically evaluate an entropy analysis of magnetohydrodynamic third-grade convection flows from permeable cylinder considering velocity and thermal slip effects. The resulting non-linear coupled partial differential conservation equations with associated boundary conditions are solved with an efficient unconditionally stable implicit finite difference Keller-Box technique. The impacts of momentum and heat transport coefficients, entropy generation and Bejan number are computed for several values of non-dimensional parameters arising in the flow equations. Streamlines are plotted to analyze the heat transport process in a two-dimensional domain. Furthermore, the deviations of the flow variables are compared with those computed for a Newtonian fluid and this has important implications in industrial thermal material processing operations, aviation technology, different enterprises, energy systems and thermal enhancement of industrial flow processes.
Źródło:
Archive of Mechanical Engineering; 2018, LXV, 3; 417-440
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Property identification of viscoelastic solid materials in nomograms using optimization techniques
Autorzy:
de Sousa, T. L.
Kanke, F.
Pereira, J. T.
Bavastri, C. A.
Powiązania:
https://bibliotekanauki.pl/articles/280283.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
identification
optimization
viscoelastic materials
Zener fractional model
Wiechert model
Opis:
Viscoelastic materials have been widely used as devices for vibration control in general. Frequently, dynamic properties of those materials are provided by manufacturers only in a graph form in the frequency domain. This is a recurring problem in industry and academia. Thereby, the goal of this work is to contribute to this important issue which is to obtain the properties of viscoelastic materials from nomograms supplied by the manufacturer. The methodology is based on the digitalization of the nomogram of the material and on the subsequent reading of a set of points from two curves in different temperatures. An optimization problem with simple restrictions is built having characteristic constants of the constitutive models as design variables. The problem is solved by applying a hybrid optimization technique. The results obtained are presented, and prove to be very promising.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 4; 1285-1297
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of single- and multi-step shear stress relaxations of isotropic magnetorheological elastomer using fractional derivative viscoelastic models
Autorzy:
Nam, T. H.
Petríková, I.
Marvalová, B.
Powiązania:
https://bibliotekanauki.pl/articles/38695689.pdf
Data publikacji:
2022
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
magnetorheological elastomer
stress relaxation
fractional viscoelastic
model
magnetic field
Opis:
The paper presents numerical simulations of single- and multi-step shear stress relaxations of isotropic magnetorheological elastomer (MRE) using fractional derivative Maxwell and Kelvin–Voigt viscoelastic models. The isotropic MRE has been fabricated by filling micro-sized carbonyl iron particles in silicone rubber. Fractional derivative Maxwell and Kelvin–Voigt viscoelastic models were used to fit the experimental data of the isotropic MRE measured by single- and multi-step relaxation tests at different constant strains and external magnetic fields. The fractional Maxwell viscoelastic model showed a relatively large difference between the measured and calculated results. The fractional Kelvin–Voigt model was fitted well with the experimental data of the isotropic MRE at various constant strain levels under different magnetic fields in both single- and multi-step shear stress relaxations. The calculated shear stress with the long-term prediction is in excellent agreement with the measured one. Therefore, the fractional derivative Kelvin–Voigt viscoelastic model is applicable to predict the long-term stress relaxation of the isotropic MRE.
Źródło:
Archives of Mechanics; 2022, 74, 4; 251-266
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Corneal hyper-viscoelastic model: derivations, experiments, and simulations
Autorzy:
Su, P.
Yang, Y.
Song, Y
Powiązania:
https://bibliotekanauki.pl/articles/307042.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
rogówka
biomechanika
hiperelastyczność
lepkosprężystość
cornea
biomechanics
constitutive model
hyperelastic
viscoelastic
Opis:
Purpose: The aim of this study is to propose a method to construct corneal biomechanical model which is the foundation for simulation of corneal microsurgery. Methods: Corneal material has two significant characteristics: hyperelastic and viscoelastic. Firstly, Mooney–Rivlin hyperelastic model of cornea obtained based on stored-energy function can be simplified as a linear equation with two unknown parameters. Then, modified Maxwell viscoelastic model of the cornea, whose analytical form is consistent with the generalized Prony-series model, is proposed from the perspective of material mechanics. Results: Parameters of the model are determined by the uniaxial tensile tests and the stress-relaxation tests. Corneal material properties are simulated to verify the hyper-viscoelastic model and measure the effectiveness of the model in the finite element simulation. On this basis, an in vivo model of the corneal is built. And the simulation of extrusion in vivo cornea shows that the force is roughly nonlinearly increasing with displacement, and it is consistent with the results obtained by extrusion experiment of in vivo cornea. Conlusions: This paper derives a corneal hyper-viscoelastic model to describe the material properties more accurately, and explains the mathematical method for determination of the model parameters. The model is an effective biomechanical model, which can be directly used for simulation of trephine and suture in keratoplasty. Although the corneal hyper-viscoelastic model is taken as the object of study, the method has certain adaptability in biomechanical research of ophthalmology.
Źródło:
Acta of Bioengineering and Biomechanics; 2015, 17, 2; 73-84
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modification of Hookes law for multiaxial stress in viscoelastic solids
Autorzy:
Kolenda, J.
Powiązania:
https://bibliotekanauki.pl/articles/258894.pdf
Data publikacji:
2008
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
Hooke's law
viscoelastic material
Kelvin-Voigt’s model
multiaxial loading
Opis:
On the basis of Hooke’s law for multiaxial stress in elastic solids, similar relationships for viscoelastic materials are considered. It is assumed that the material is homogeneous and isotropic, and that the Kelvin-Voigt’s model is applicable to normal strain components. An analogous model is also taken for shear strain components. It is shown that the ratio of coefficients of viscous damping of normal and shear strain components is equal to the ratio of Young modulus and shear modulus. As a result, the modified Hooke’s law for multiaxial stress in viscoelastic materials has been formulated which includes three material constants: Young modulus, Poisson’s ratio and coefficient of viscous damping of normal strain.
Źródło:
Polish Maritime Research; 2008, 2; 22-25
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza lepkosprężysta zachowania się konstrukcji nawierzchni drogowej w zależności od temperatury i warunków obciążenia
Viscoelastic analysis of asphalt pavement structure behavior depending on the pavement temperature and loading conditions
Autorzy:
Mejłun, Ł.
Judycki, J.
Dołżycki, B.
Powiązania:
https://bibliotekanauki.pl/articles/144465.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Inżynierów i Techników Komunikacji Rzeczpospolitej Polskiej
Tematy:
analiza lepkosprężystości
podatna konstrukcja nawierzchni
model Burgersa
viscoelastic analysis
flexible pavement structure
Burgers model
Opis:
Przedmiotem artykułu jest analiza lepkosprężysta podatnej konstrukcji nawierzchni drogowej w warunkach wysokich temperatur. W analizie wykorzystano model lepkosprężystości Burgersa warstw asfaltowych. Parametry modelu wyznaczono w oparciu o wyniki badania mieszanek mineralno-asfaltowych pod obciążeniem powtarzalnym. Analizowano wpływ rozkładu temperatury, ciężaru koła i prędkości ruchu na ugięcia powierzchni jezdni i odkształcenia spodu warstw asfaltowych.
This paper presents viscoelastic analysis of flexible pavement structure at high temperature. Viscoelastic Burgers model was used in the analysis. Model parameters were determined based on dynamic modulus test results. The authors analyzed the influence of temperature distribution, wheel movement speed and wheel loading on pavement deflections and strains at the bottom of asphalt layers.
Źródło:
Drogownictwo; 2015, 10; 341-347
0012-6357
Pojawia się w:
Drogownictwo
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie ułamkowych modeli reologicznych do oceny właściwości lepkosprężystych żeli skrobiowych
Application of fractional rheological models for the assessment of viscoelastic properties of starch gels
Autorzy:
Orczykowska, M.
Powiązania:
https://bibliotekanauki.pl/articles/2073135.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
ułamkowy model reologiczny
żele skrobiowe
właściwości lepkosprężyste
fractional rheological model
starch paste
viscoelastic properties
Opis:
Przedstawiono analizę stanu mechanicznego struktury żeli skrobiowych otrzymanych ze skrobi o różnym pochodzeniu botanicznym. Oceny struktury żeli skrobiowych dokonano na podstawie zaproponowanego, własnego, ułamkowego modelu reologicznego. Stanowi on uogólnienie propozycji Maxwella-Wiecherta, która dotyczyła sposobu łączenia elementów mechanicznych. Wyznaczono parametry reologiczne tego modelu i oceniono ich zależność od zawartości amylozy w żelach skrobiowym.
Analysis of mechanical structure of starch gels obtained from starches of different botanical sources is presented in the paper. The assessment of starch gel structure was made using the own fractional rheological model being the generalization of Maxwell-Wiechert approach dealing with mechanical components combination. The rheological parameters of this model were determined and their dependence on the content in starch gel was estimated.
Źródło:
Inżynieria i Aparatura Chemiczna; 2015, 6; 344--345
0368-0827
Pojawia się w:
Inżynieria i Aparatura Chemiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelowanie ośrodka lepkosprężystego w metodzie elementów czasoprzestrzennych
Modelling of a viscoelastic continuum with the use of space-time element method
Autorzy:
Lachowicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/104400.pdf
Data publikacji:
2017
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
ośrodek lepkosprężysty
metoda elementów czasoprzestrzennych
model obliczeniowy
viscoelastic continuum
space time element method
calculation model
Opis:
W pracy rozpatruje się ośrodek lepkosprężysty, który został opisany równaniami całkowymi (model całkowy) z wykorzystaniem funkcji relaksacji (tensorowej funkcji relaksacji).Opracowano model obliczeniowy do analizy takich ośrodków z użyciem metody elementów czasoprzestrzennych. Zamieszczony przykład obliczeń (tarcza lepkosprężysta) wskazuje na poprawność i efektywność tego modelu obliczeniowego.
The article deals with a viscoelastic continuum which is described by integral equationsi (integral model) with the use of relaxation function (tensor relaxation function). A calculation model for analysis of such continuums with the use of time-space elements has been developed. The included calculation example (viscoelastic disc) indicates correctness and effectiveness of this calculation model.
Źródło:
Czasopismo Inżynierii Lądowej, Środowiska i Architektury; 2017, 64, 3/I; 559-569
2300-5130
2300-8903
Pojawia się w:
Czasopismo Inżynierii Lądowej, Środowiska i Architektury
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Viscoelastic Characterization of Different Solid Rocket Propellants Using the Maxwell Spring-Dashpot Model
Autorzy:
Shekhar, H.
Kankane, D. K.
Powiązania:
https://bibliotekanauki.pl/articles/358207.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
damping coefficient
Maxwell model
rocket propellants
spring constant
tensile test
viscoelastic properties
Opis:
A single spring and a single dashpot in series was utilized to simulate the stress-strain curve for different classes of solid rocket propellants, namely extruded double base propellants (EDBP) and composite propellants (CP), in the uniaxial tensile mode in a constant rate of travel machine. The propellant behaves as a viscoelastic material and invariably exhibits stress relaxation, which cannot be simulated by elastic mechanical property parameters. In order to generate a complete stress-strain curve of a solid rocket propellant under tensile testing, different classes of solid rocket propellants were evaluated and the stress-strain curve generated was modelled using the single spring-single dashpot Maxwell fluid model. Using two constants, called the spring constant (K) and the damping factor (D), it was possible to generate a complete stress-strain curve. Mathematical formulation gives the stress (σ) - strain (ε) relation as….[wzór]. Additionally the physical nature of the spring constant resembles that of the elastic constant and the damping coefficient gives the contribution of the viscous part of the load bearing capacity of solid rocket propellants. The development of a general mathematical formulation, the calculation of constants for different classes of propellants and insight into the viscoelastic nature of propellants are the main themes of this article. For all classes of propellants, two ratios are defined. The first is a dimensionless parameter 'H', which is the ratio of the spring constant to the initial elastic modulus. The second is the ratio of the damping coefficient to the spring constant depicted by parameter 'S'. The spring constant is higher than the initial elastic modulus and the value of 'H' is always higher than 1. For brittle propellants (extruded double base propellants, EDBPs, with a high elastic modulus), the spring constant is numerically very close to the spring constant (H is around 1.75). As the ductility (percentage elongation) of the solid rocket propellants increases (from cartridge loaded composite propellants, CLCPs, to case-bonded composite propellants, CBCPs), the value of parameter 'H' also increases (H ~ 10 for CP). For EDBPs the parameter 'S' is smaller (~ 1.24), but for CLCPs and CBCPs, it is high (S ~ 5 to 8). Both of these ratios are basic properties of the polymeric matrix. The first ratio depicts the departure of the actual stress-strain curve from linearity, while the second ratio is another way of expressing the relaxation time. A higher 'H' indicates a softer and more ductile propellant, while a higher 'S' indicates a shorter relaxation time for the propellant. A lower 'S' indicates that the propellant recovers faster on removal of strain.
Źródło:
Central European Journal of Energetic Materials; 2012, 9, 3; 189-199
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Approximate method for determination of dynamic characteristics of structures with viscoelastic dampers
Autorzy:
Lewandowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/127718.pdf
Data publikacji:
2016
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
structures
viscoelastic damper
generalized fractional model
dynamic characteristics
struktury
tłumik lepkosprężysty
uogólniony model ułamkowy
charakterystyka dynamiczna
Opis:
An approximate method for determination of dynamic characteristics of structures with viscoelastic dampers is proposed in this paper. A fractional derivative is used to describe the dynamic behaviour of viscoelastic dampers. The method is based on a continuous dependency of the sensitivity of eigenvalue on a certain artificially introduced parameter which scaled up the influence of the damping term in the eigenvalue problem. Some results of a representative calculation are also presented and briefly discussed.
Źródło:
Vibrations in Physical Systems; 2016, 27; 219-226
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On measurement point-independent identification of Maxwell model of viscoelastic materials
O niezaleznej od punktow pomiarowych identyfikacji modelu Maxwella materialow lepkosprezystych
Autorzy:
Stankiewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/791856.pdf
Data publikacji:
2012
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
viscoelasticity
relaxation modulus
Maxwell model
identification algorithm
viscoelastic material
mathematical description
convergence analysis
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2012, 12, 2
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modal analysis of frame structures with semi-rigid joints and viscoelastic connections modeled by fractional derivatives
Autorzy:
Pawlak, Z. M.
Łasecka-Plura, M.
Zak-Sawiak, M.
Powiązania:
https://bibliotekanauki.pl/articles/38697100.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
viscoelastic connection
rotational damping
rheological fractional model
dynamic characteristics of structure
modified finite element
Opis:
The paper presents two methods of solving the problem of the dynamics of a frame structure with viscoelastic bonds in nodes. In the first approach, known from the literature, two-node beam elements with three degrees of freedom in each node were used. Exact shape functions were adopted to obtain a stiffness matrix, a consistent mass matrix and a damping matrix for the beam element. These matrices were then modified by introducing rotational viscoelastic constraints at the boundary nodes. In the second approach, a new method of modelling viscoelastic bonds in frame structures was proposed. It consists in removing rigid bonds between elements along selected degrees of freedom and replacing them with a new, additional element with viscoelastic properties. This approach allows the use of any rheological model to describe viscoelastic bonds (i.e. an additional element) without the need to create a new modified finite element. In this work, an advanced rheological model, i.e. the fractional Kelvin model, was used to describe rotational viscoelastic bonds. The use of fractional derivatives to describe the damping properties reduces the number of parameters needed in the model, but leads to a non-linear eigenproblem. In order to solve the eigenvalue problem, the continuation method was used, and the dynamic characteristics of the structure were determined on the basis of the calculated eigenvalues. Selected structures with viscoelastic nodes were analyzed and the obtained results confirm the effectiveness of the proposed approach.
Źródło:
Archives of Mechanics; 2023, 75, 3; 337-363
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 16

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