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  1. 5 Archives of Control Sciences
  2. 3 Bulletin of the Polish Academy of Sciences. Technical Sciences
  3. 3 Journal of Applied Analysis
  4. 3 Mechanics and Mechanical Engineering
  5. 3 Opuscula Mathematica
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  1. 8 Kaczorek T.
  2. 4 Kaczorek Tadeusz
  3. 2 El-Kholy S. A.
  4. 2 Panigrahi S
  5. 1 Agilan V.
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  1. 1 2024
  2. 2 2022
  3. 1 2021
  4. 4 2020
  5. 4 2019
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1
Content available Seismic Structure-Soil-Structure Interaction (SSSI) between piled neighboring bridges: Influence of height ratio
Alfach Mohanad Talal
Studia Geotechnica et Mechanica
|
2024
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Vol. 46, nr 1
45--75
EN
This paper explores the impact of height ratios on the seismic Structure-Soil-Structure Interaction (SSSI) for three adjacent bridges with varying superstructure masses (Mst = 350, 1050, 350 t) through 3D numerical simulations. A comprehensive series of numerical analyses has been conducted across different height ratios (R = 1, 1.1, 1.15, 1.2, 1.25, 1.5, 2, and 3) to assess their influence on superstructure acceleration and the internal forces within the foundation piles. The bridges under investigation are supported by groups of piles embedded in nonlinear clay. The numerical simulations were executed using fast Lagrangian analysis of continua in three dimensions (FLAC 3D), a three-dimensional finite differences modeling software. The findings revealed that variations in mass ratios significantly impact the SSSI effects on superstructure acceleration and pile internal forces. Notably, adverse effects were more pronounced for mass ratios of R = 1.1 and 1.2, leading to an increase in bending moment, shear force, and superstructure acceleration by up to 237.8%, 291.4%, and 70.33%, respectively. In contrast, a mass ratio of R = 3 resulted in a decrease in bending moment, shear force, and superstructure acceleration by up to 72%, 82.14%, and 81.13%, respectively. This implies that a careful arrangement of adjacent structures with different masses can be employed effectively to manage the (SSSI) effects.
2
Content available remote Fourth order qualitative inspection of nonlinear neutral delay difference equation
Jesinthaangel R., Jawahar G. Gomathi, Aruna K.
Przegląd Elektrotechniczny
|
2022
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R. 98, nr 7
66--69
EN
This paper aim is to investigate the nonlinear neutral fourth order difference equation in the form. We establish some conditions to assure that all solutions to this equation are oscillatory or nonoscillatory. We derived this using summation averaging technique and comparison principle. The main outcomes are illustrated using examples.
PL
W artykule badano nieliniowe równanie różnicowe czwartego rzędu. Ustalamy pewne warunki, aby zapewnić, że wszystkie rozwiązania tego równania są oscylacyjne lub nieoscylacyjne. Wyprowadziliśmy to za pomocą techniki uśredniania sumowania i zasady porównania. Główne wyniki zilustrowano na przykładach.
3
Content available Exponential decay of transient values in discrete-time positive nonlinear systems
Kaczorek Tadeusz, Ruszewski Andrzej
Archives of Control Sciences
|
2022
|
Vol. 32, No. 3
577--588
EN
The exponential decay of transient values in discrete-time nonlinear standard and fractional orders systems with linear positive linear part and positive feedbacks is investigated. Sufficient conditions for the exponential decay of transient values in this class of positive nonlinear systems are established. A procedure for computation of gains characterizing the class of nonlinear elements are given and illustrated on simple example.
4
Content available Experimental and numerical studies on the shear stability of ship’s thin plates
Li Xiaowen, Zhu Zhaoyi, Chen Qinglin, Cai Yingqiang, Peng Miaojiao
Polish Maritime Research
|
2021
|
nr 4
133--141
EN
The stability of thin plate plays an important role in the design and strength check of ship structure. In order to study the shear stability of ship’s thin plates, in-plane shear buckling tests were carried out using a picture frame fixture and a 3D full-field strain measurement system. The critical buckling load, full-field displacement/strain information, and load-displacement curve were obtained. The finite element model with the frame fixture was established based on ABAQUS, with the eigenvalue buckling analysis and nonlinear buckling analysis being carried out to obtain the mechanical response information of the buckling and post-buckling of the ship’s thin plate. The effectiveness and accuracy of the numerical simulation method are verified by comparing the numerical simulation with the experimental results. On this basis, the critical buckling load obtained by shear test, numerical simulation, and theoretical calculation is analyzed, and the function of the frame shear fixture and its influence on the critical buckling load are defined. The research in this paper provides a useful reference for the testing and simulation of in-plane shear stability of ship’s thin plates.
5
Content available New sufficient conditions of global stability of nonlinear positive electrical circuits
Kaczorek Tadeusz
Poznan University of Technology Academic Journals. Electrical Engineering
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2020
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No. 103
7--14
EN
The global stability of electrical circuits composed of positive linear parts and nonlinear static element with given characteristic and positive gain feedbacks is investigated. New sufficient conditions for the global stability of this class of nonlinear positive electrical circuits are established. These new stability conditions are demonstrated on simples examples of positive nonlinear electrical circuits.
6
Content available On the qualitative behavior of the solutions to second-order neutral delay differential equations
Chatzarakis George E., Santra Shyam S.
Fasciculi Mathematici
|
2020
|
nr 64
43--56
EN
In this paper, we study the qualitative behavior of the solutions to second-order neutral delay differential equations of the form (r(t) ((x(t) + p(t)x(τ (t)))′)γ)′ + q(t)f (x(σ(t))) = 0. Our main tool is Lebesgue’s dominated convergence theorem. Examples illustrating the applicability of the results are also given.
7
Content available Nonlinear method of precrash velocity determination for Mini car class-B-spline tensors products with probabilistic weights
Mrowicki Adam, Kubiak Przemysław, Zakrzewicz Wojciech
Archiwum Motoryzacji
|
2020
|
Vol. 87, nr 1
97--108
EN
Following paper introduces the nonlinear method of determining the velocity of a vehicle before the impact-the Equivalent Energy Speed (EES). To estimate the magnitude of EES, the method utilizes the deformation work Wdef of the vehicle, defined by the quotient of deformation coefficient Cs and plastic deformation. Combined with the introduction of the B-spline tensor products and least square approximation with probabilistic weights, method shows promising results.
8
Content available Global stability of discrete-time nonlinear systems with descriptor standard and fractional positive linear parts and scalar feedbacks
Kaczorek T., Ruszewski A.
Archives of Control Sciences
|
2020
|
Vol. 30, No. 4
667--681
EN
The global stability of discrete-time nonlinear systems with descriptor positive linear parts and positive scalar feedbacks is addressed. Sufficient conditions for the global stability of standard and fractional nonlinear systems are established. The effectiveness of these conditions is illustrated on numerical examples.
9
Content available Global stability of nonlinear feedback systemswith positive descriptor linear parts
Kaczorek T.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2019
|
Vol. 67, nr 1
45--51
EN
The global (absolute) stability of nonlinear systems with negative feedbacks and positive descriptor linear parts is addressed. Transfer matrices of positive descriptor linear systems are analyzed. The characteristics u = f (e) of the nonlinear parts satisfy the condition k1e ≤ f (e) ≤ k2e for some positive k1, k2. It is shown that the nonlinear feedback systems are globally asymptotically stable if the Nyquist plots of the positive descriptor linear parts are located in the right-hand side of the circles (– 1/k1, – 1/k2).
10
Content available Absolute stability of a class of positive nonlinear continuous-time and discrete-time systems
Kaczorek Tadeusz
Archives of Control Sciences
|
2019
|
Vol. 29, No. 1
157--167
EN
The positivity and absolute stability of a class of nonlinear continuous-time and discrete-time systems are addressed. Necessary and sufficient conditions for the positivity of this class of nonlinear systems are established. Sufficient conditions for the absolute stability of this class of nonlinear systems are also given.
11
Content available Absolute stability of a class of nonlinear systems with nonpositive linear parts
Kaczorek Tadeusz
Archives of Control Sciences
|
2019
|
Vol. 29, No. 2
247--258
EN
The positivity and absolute stability of a class of nonlinear continuous-time and discrete-time systems with nonpositive linear part are addressed. Necessary and sufficient conditions for the positivity of this class of nonlinear systems are established. Sufficient conditions for the absolute stability of this class of nonlinear systems are also given.
12
Content available remote Modelling spatial variation of extreme precipitation over Ho Chi Minh City under nonstationary conditio
Binh Le Thi Hoa, Agilan V., Umamahesh N. V., Rathnam E. V.
Acta Geophysica
|
2019
|
Vol. 67, no. 3
849--861
EN
Understanding the magnitude and spatial variation of extreme rainfall events are required for decision making and adaptation strategies for flood risk. In Ho Chi Minh City (HCMC), heavy rainfall, which is considered as a main cause of floods, witnessed an increase in frequency and magnitude in last few decades. Although nonstationarity in extreme rainfall has been proved in many places of the world, research into nonstationarity feature in extreme rainfall in HCMC has not been paid attention thoroughly. In this study, the spatial variation of extreme precipitation over Ho Chi Minh City is modelled under nonstationary condition. The generalized extreme value (GEV) distribution with location made a nonlinear function of time is applied to annual maximum daily rainfall. The study results show that the nonstationary GEV model is found to be superior in capturing extreme precipitation events when compared to the stationary GEV model. The extreme rainfall estimates under the stationary condition are lower than those under the nonstationary condition in most stations. Besides, the spatial variation of extreme rainfall under nonstationary condition shows a significant difference in extreme estimates between the periods of 1980–1984 and 2010–2014 in study area.
13
Content available Nonlinear modeling and analysis of a shock absorber with a bypass
Ferdek U., Łuczko J.
Journal of Theoretical and Applied Mechanics
|
2018
|
Vol. 56 nr 3
615—629
EN
The model of a mono-tube shock absorber with a bypass is proposed in this paper. It is shown that the application of an additional flow passage (bypass) causes changes to the damping force characteristics when the excitation amplitudes are large. In such cases, the damping force values increase, thereby improving safety of the ride. For small excitation amplitudes, the shock absorber behaves in a similar fashion as shock absorbers without a bypass, ensuring a high comfort level of the ride on roads with smooth surfaces.
14
Oscillatory behavior of higher order nonlinear homogeneous neutral delay dynamic equations with positive and negative coefficients
Panigrahi S., Reddy P. R.
Journal of Applied Analysis
|
2018
|
Vol. 24, nr 2
139--154
EN
In this paper, we derive some sufficient conditions for the oscillatory and asymptotic behavior of solutions of the higher order nonlinear neutral delay dynamic equation with positive and negative coefficients. The results of this paper extend and generalize the results of [S. Panigrahi and P. Rami Reddy, Oscillatory and asymptotic behavior of fourth order non-linear neutral delay dynamic equations, Dyn. Contin. Discrete Impuls. Syst. Ser. AMath. Anal. 20 (2013), 143-163] and [S. Panigrahi, J. R. Graef and P. Rami Reddy, Oscillation results for fourth order nonlinear neutral dynamic equations, Commun. Math. Anal. 15 (2013), 11-28]. Examples are included to illustrate the validation of the results.
15
Content available A discrete model for nonlinear vibrations of a simply supported cracked beams resting on elastic foundations
Khnaijar A., Benamar R.
Diagnostyka
|
2017
|
Vol. 18, No. 3
39--46
EN
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.
16
Content available Existence theorems of nonlinear asymptotic BVP for a homeomorphism
Szymańska-Dębowska K.
Opuscula Mathematica
|
2016
|
Vol. 36, no. 3
399--407
EN
In this work, we are concerned with the existence of solutions for the following φ -Laplacian boundary value problem on the half-line [formula] where [formula] is continuous. The results are proved using the properties of the Leray-Schauder topological degree.
17
Content available remote Investigation on growth, optical and thermal properties of stilbazolium derivative crystal: 4-N,N-dimethylamino-40-N0-methylstilbazolium 2,4-dimethylbenzenesulfonate
Md Zahid I., Kalaiyarasi S., Kumar M. K., Ganesh T., Jaisankar V., Kumar R. M.
Materials Science Poland
|
2016
|
Vol. 34, No. 4
811--818
EN
Metathesis ionic exchange reaction process was used to synthesize a novel nonlinear optical material: 4-N,N-dimethylamino-4′- N′-methylstilbazolium 2,4-dimethylbenzenesulfonate (DSDMS). The growth of DSDMS single crystals was carried out by adopting the solution growth technique. The crystal perfection and lattice parameters were elucidated from single XRD and powder XRD, respectively and its morphology was interpreted by WinXMorph program. FT-IR and Raman spectral analyses confirmed the existence of functional groups and their corresponding vibrational modes. UV-Vis spectral studies revealed the optical transmission region. Mechanical stability of the crystal was determined from Vickers microhardness number Hv, Meyer’s index n and elastic stiffness constant C11. Dielectric and thermal behavior of the grown crystal were elucidated by using impedance analyser and thermogravimetric analysis.
18
Content available Nonlinear degradation modeling and maintenance policy for a two-stage degradation system based on cumulative damage model
Ni X., Zhao J., Song W., Guo C., Li H.
Eksploatacja i Niezawodność
|
2016
|
Vol. 18, no. 2
171--180
EN
This paper attempts to take into account a two-stage degradation system which degradation rate is non-stationary and change over time. The system degradation is thought to be caused by shocks, and system degradation model is established based on cumulative damage model. The nonlinear degradation process is expressed by different shock damage and shock counting. And shock damage and shock counting are assumed to be Gamma distribution and non-homogeneous Poisson process, respectively. On the basis of these, system reliability model and nonlinear degradation model are given. In order to optimal maintenance policy for considered system, adaptive maintenance policy and time-dependent maintenance policy are studied, and mean maintenance cost rate is established to evaluate the maintenance policies. Numerical examples are given to analyze the influences of degradation model parameters and find optimal maintenance policy for considered system.
PL
W przedstawionym artykule badano system, w którym proces degradacji zachodzi dwuetapowo, a szybkość degradacji jest zmienna w czasie. Przyjęto, że do degradacji systemu dochodzi w wyniku wstrząsów. Model degradacji systemu oparto na modelu sumowania uszkodzeń. Nieliniowy proces degradacji określono jako taki, w którym uszkodzenie powodowane wstrząsem oraz częstotliwość wstrząsów są wartościami zmiennymi. Przyjęto, że uszkodzenie powodowane wstrząsem ma rozkład gamma a częstotliwość wstrząsów jest niejednorodnym procesem Poissona. Na tej podstawie utworzono model niezawodności systemu oraz model degradacji nieliniowej. W celu opracowania optymalnej strategii eksploatacji dla rozpatrywanego systemu, rozważono dwa typy strategii utrzymania ruchu: strategię adaptacyjną oraz strategię czasowo-zależną. Strategie te oceniano określając średni poziom kosztów eksploatacji. Przykłady numeryczne posłużyły do analizy wpływu parametrów modelu degradacji oraz pozwoliły określić optymalną strategię utrzymania dla rozpatrywanego systemu.
19
Content available Analysis of positivity and stability of fractional discrete-time nonlinear systems
Kaczorek T.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2016
|
Vol. 64, nr 3
491--494
EN
The positivity and asymptotic stability of the fractional discrete-time nonlinear systems are addressed. Necessary and sufficient conditions for the positivity and sufficient conditions for the asymptotic stability of the fractional nonlinear systems are established. The proposed stability tests are based on an extension of the Lyapunov method to the positive fractional nonlinear systems. The effectiveness of tests is demonstrated on examples.
20
Content available Prediction of site response spectrum under earthquake vibration using an optimized developed artificial neural network model
Esmaeilabadi R., Shahri A. A.
Advances in Science and Technology. Research Journal
|
2016
|
Vol. 10, nr 30
76--83
EN
Site response spectrum is one of the key factors to determine the maximum acceleration and displacement, as well as structure behavior analysis during earthquake vibrations. The main objective of this paper is to develop an optimized model based on artificial neural network (ANN) using five different training algorithms to predict nonlinear site response spectrum subjected to Silakhor earthquake vibrations is. The model output was tested for a specified area in west of Iran. The performance and quality of optimized model under all training algorithms have been examined by various statistical, analytical and graph analyses criteria as well as a comparison with numerical methods. The observed adaptabilities in results indicate a feasible and satisfactory engineering alternative method for predicting the analysis of nonlinear site response.
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