Search results for: NUMERICAL SIMULATION: IMPACT ECHO
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Safety assessment of a concrete viaduct damaged by vehicle impact and an evaluation of the repair
PublicationDamage to lower parts of viaducts caused by impact from under-passing high vehicles is relatively frequent. One such incident, in which a viaduct was damaged by the impact from a truck with an improperly assembled hydraulic crane, is considered in this work. The analysis is based on a detailed object damage evaluation, 3D laser scanning, and numerical simulations. The aim of the study is to accurately model the vehicle impact into...
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Aneta Sobiechowska-Ziegert dr
PeopleShe works at the Department of Statistics and Econometrics at the Faculty of Management and Economics. She is passionate about using modern teaching methods in quantitative subjects. She is a certified coach and tutor. She teaches courses in economic forecasting and spatial econometrics. She is also the chair of the Faculty's Quality of Education Committee and oversees the EMOS education track, certified by Eurostat. Currently,...
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Long-term hindcast simulation of sea level in the Baltic Sea
Open Research DataThe dataset contains the results of numerical modelling of sea level fluctuations over a period of 50 years (1958-2007) in the Baltic Sea. A long-term hindcast simulation was performed using a three-dimensional hydrodynamic model PM3D (Kowalewski and Kowalewska-Kalkowska, 2017), a new version of the M3D model (Kowalewski, 1997). The hydrodynamic model...
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Generalization of Kramers-Krönig relations for evaluation of causality in power-law media
PublicationClassical Kramers-Krönig (K–K) relations connect real and imaginary parts of the frequency-domain response of a system. The K–K relations also hold between the logarithm of modulus and the argument of the response, e.g. between the attenuation and the phase shift of a solution to a wave-propagation problem. For square-integrable functions of frequency, the satisfaction of classical K–K relations implies causality in the time domain....
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Comments on various extensions of the Riemann–Liouville fractional derivatives : About the Leibniz and chain rule properties
PublicationStarting from the Riemann–Liouville derivative, many authors have built their own notion of fractional derivative in order to avoid some classical difficulties like a non zero derivative for a constant function or a rather complicated analogue of the Leibniz relation. Discussing in full generality the existence of such operator over continuous functions, we derive some obstruction Lemma which can be used to prove the triviality...
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Justification of quasi-stationary approximation in models of gene expression of a self-regulating protein
PublicationWe analyse a model of Hes1 gene transcription and protein synthesis with a negative feedback loop. The effect of multiple binding sites in the Hes1 promoter as well as the dimer formation process are taken into account. We consider three, possibly different, time scales connected with: (i) the process of binding to/dissolving from a binding site, (ii) formation and dissociation of dimers, (iii) production and degradation of Hes1...
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Signal propagation in electromagnetic media described by fractional-order models
PublicationIn this paper, signal propagation is analysed in electromagnetic media described by fractional-order (FO) models (FOMs). Maxwell’s equations with FO constitutive relations are introduced in the time domain. Then, their phasor representation is derived for one-dimensional case of the plane wave propagation. With the use of the Fourier transformation, the algorithm for simulation of the non-monochromatic wave propagation is introduced....
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Electromagnetic-based derivation of fractional-order circuit theory
PublicationIn this paper, foundations of the fractional-order circuit theory are revisited. Although many papers have been devoted to fractional-order modelling of electrical circuits, there are relatively few foundations for such an approach. Therefore, we derive fractional-order lumped-element equations for capacitors, inductors and resistors, as well as Kirchhoff’s voltage and current laws using quasi-static approximations of fractional-order...
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Discrete and continuous fractional persistence problems – the positivity property and applications
PublicationIn this article, we study the continuous and discrete fractional persistence problem which looks for the persistence of properties of a given classical (α=1) differential equation in the fractional case (here using fractional Caputo’s derivatives) and the numerical scheme which are associated (here with discrete Grünwald–Letnikov derivatives). Our main concerns are positivity, order preserving ,equilibrium points and stability...
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Modelling and simulations in time-fractional electrodynamics based on control engineering methods
PublicationIn this paper, control engineering methods are presented with regard to modelling and simulations of signal propagation in time-fractional (TF) electrodynamics. That is, signal propagation is simulated in electromagnetic media described by Maxwell’s equations with fractional-order constitutive relations in the time domain. We demonstrate that such equations in TF electrodynamics can be considered as a continuous-time system of...
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An absorbing set for the Chialvo map
PublicationThe classical Chialvo model, introduced in 1995, is one of the most important models that describe single neuron dynamics. In order to conduct effective numerical analysis of this model, it is necessary to obtain a rigorous estimate for the maximal bounded invariant set. We discuss this problem, and we correct and improve the results obtained by Courbage and Nekorkin (2010). In particular, we provide an explicit formula for an...
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Model-based testing for execution algorithms in the simulation of cyber-physical systems
PublicationThe understanding of simulation semantics of a hybrid system is a challenge for computational engineers as it requires expertise in computer science, engineering, numerical methods, and mathematics at once. The testing methods for the execution of a simulation are being researched but not yet applied on the industrial level. Consequently, the semantics of the simulation becomes a critical artifact in the system development process....
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Identification of ship’s hull mathematical model with numerical methods
PublicationThe modern maritime industry is moving toward the development of technology that will allow for full or partial autonomy of ship operation. This innovation places high demands on ship performance prediction techniques at the design stage. The researchwork presented in the article is related to the design stage of the ship and concerns methods for prognosis and evaluation of the specific operational condition of the ship, namely...
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Initial Report on Numerical Modeling of Blood Flow in Myocardial Bridge Region of Coronary Artery: Concept of Model Validation
PublicationThe paper presents a numerical method of blood flow simulation within the coronary artery covered by the myocardial bridge. The myocardial bridge is a congenital coronary abnormality caused by the blood vessel location under one of the heart muscles. In this case, the blood flow within the vessel is partially disturbed which can cause several consequences. The presented numerical simulation allowed us to estimate the blood flow...
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Modelling of shear zones during quasi-static granular silo flow using material point method (MPM)
PublicationThe paper focuses on confined silo flow of cohesionless sand. The problem considered is a quasi-static flow in a plane strain model silo with parallel walls simulated with the material point method (MPM). The simulation used a non-local hypoplastic constitutive model. Initially, the paper validated the implemented numerical approach with basic element tests and a plane strain compression test. The subsequent MPM calculations for...
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Long-term hindcast simulation of water temperature and salinity in the Baltic Sea
Open Research DataThe dataset contains the results of numerical modelling of water temperature and salinity over a period of 50 years (1958-2007) in the Baltic Sea. A long-term hindcast simulation was performed using a three-dimensional hydrodynamic model PM3D (Kowalewski and Kowalewska-Kalkowska, 2017), a new version of the M3D model (Kowalewski, 1997). The hydrodynamic...
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MODELLING OF TRANSIENT FLOW IN STORM SEWERS
PublicationThe paper focuses on the assessment of second-order explicit numerical scheme for unsteady flows in sewers. In order to simulate the pressurized flow the 'Preissmann slot' concept is implemented. For simulation of the transcritical flow the original and improved McCormack scheme is used. The calculated results are compared with numerical solutions and laboratory measurements published in the technical literature. Moreover, the...
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Numerical crash analysis of the cable barrier
PublicationSafety barriers are used to increase road safety. Their basic task is to prevent the errant vehicle from getting off the road in places which are potentially dangerous for vehicle passengers. Barriers, which are used on European roads, must fulfill the requirements of EN 1317 standards by passing appropriate crash tests. Because of their high cost, numerical simulations are increasingly used to evaluate the properties of safety...
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Comparing N3-60 cascade exit angles obtained from tunnel measurements and numerical calculations
PublicationThe article compares the results of measurements performed in the aerodynamic tunnel at CUT and numerical simulation carried out for a plane cascade of N3-60 profiles. Comparing the measured and calculated results provides opportunities for assessing the range of systematic differences between simulation predictions and actual experimental results.
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Comparative Analysis of Numerical and Experimental Studies of the Airflow Around the Sample of Urban Development
PublicationIn this paper, on the background of a short overview of the recent advances in the field of Environmental Wind Engineering (EWE), a comparison of wind tunnel experiment and numerical simulation for some cases of airflow around an urban layout have been reported. The purpose of the study is quantitative and qualitative comparison of measurements in the wind tunnel as well as numerical simulation using Ansys Fluent software. The...
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Numerical Simulations for Transonic Flow in Control Valve
PublicationResults of numerical simulations for transonic flow in control valve are presented. The valve is the main part of an adaptive pneumatic shock absorber. Flow structure in the valve domain and the influence of the flow non-uniformity in the valve on a mass flow rate is investigated. Numerical simulation results are compared with experimental data.
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CFD Simulations and Tests of a Prototype Flow Control Valve
PublicationIn this paper a prototype of a flow control valve is described and numerically simulated. The flow control valve is used in hydraulic systems to maintain constant fluid flow despite changing loads of a receiver. The standard construction of this type of valves is modified mainly by eliminating the spring. The prototype consists the hydrostatically unloaded throttle valve and pressure ratio valve substituting pressure difference...
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Micro-modelling of shear localization during quasi-static confined granular flow in silos using DEM
PublicationThe paper deals with the quasi-static confined flow of cohesionless sand in a plane strain model silo with parallel walls and a slowly movable bottom. Numerical modelling was carried out by the discrete element method (DEM) using spheres with contact moments to approximately capture a non-uniform shape of sand particles. Different initial void ratios of sand and silo wall roughness grades were employed. Regular triangular grooves...
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Possible effects of the 1984 St. Clair River ice jam on bed changes
PublicationThis study examines the possible effect of the record ice jam of 1984 in the St. Clair River on river bed changes and conveyance. Numerical simulations were made to examine the flow and bed shear stresses during the jam formation and release periods. Simulation results indicate that the ice jam in the river did not cause a significant increase in bed shear stress compared to pre- and post-jam open water conditions. The insignificant...
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Systematic Management of Simulation State for Multi-Branch Simulations in Simulink
PublicationSystematic simulation is a technique related and motivated by the formal analysis of hybrid dynamic systems. It combines the exhaustive and conservative nature of traditional model checking with numerical simulation for providing efficient algorithms to manage simulations. Multi-branch simulation is the concept advancing simulation efficiency by reducing the number of state transitions. This paper introduces an approach to implement...
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Damage detection in turbine wind blades by vibration based methods
PublicationThe paper describes results of numerical simulation for damage localization in the composite coat of a wind turbine blade usingmodal parameters and a modern damage detection method (wavelet transform).
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EH36 steel for shipbuilding (plate thicnkness 30 mm) - 3D fracture scan
Open Research DataThe basic method of ductility designation of structural steels is the Charpy impact test. The test consists of a single strike of the specimen using a Charpy pendulum. Its result is the value of work necessary to break a specimen at a test temperature. Despite its many advantages, such as its short implementation time and low costs, it has its disadvantages,...
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Hydrodynamic reanalysis of ice conditions in the Baltic Sea using the PM3D model
Open Research DataThe dataset contains the results of numerical modeling of sea ice in the Baltic Sea since 1998. A long-term reanalysis was performed using the three-dimensional hydrodynamic model PM3D (Kowalewski and Kowalewska-Kalkowska, 2017), a new version of the M3D model (Kowalewski, 1997). A numerical dynamic-thermodynamic model of sea ice (Herman et al. 2011)...
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Karol Grębowski dr inż.
PeopleKarol Grębowski (M.Sc.) works as an assistant at the Department of Technical Fundamentals of Architecture Design of the Faculty of Architecture at Gdansk University of Technology. His scientific research deals with dynamic phenomena occurring during the vibration of structures, bridges, and studies the design methodology of the elements forming passive protection system of the vehicles degraded by struck or explosion in the context...
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A study on application of Smoothed Particle Hydrodynamics to multi-phase flows
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Numerical Analysis of a Steel Frame Building with Soft-storey Failure under Ground Motion Excitation
PublicationThe aim of this paper is to show the results of a numerical analysis focused on the behaviour of multi-storey steel frame building that suffers from a soft-storey failure under ground motion excitation. A numerical model of the structure was created in FEM computer software and was exposed to an impact that would have been generated after a soft-storey failure due to falling of the upper floors. During the analysis, the whole structure...
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Analysis of cyclone separator solutions depending on SEC outlet conditions in nCO2PP
PublicationUtilization of spray ejector condenser in order to carry out direct-contact condensation of vapour with inert gas (CO2) on a spray of subcooled liquid integrated with separator (to make pure CO2) has been proposed for the task of condensation and CO2 separation in the negative CO2 emission gas power plant. Condensation and separation has a significant impact on the thermodynamic efficiency of the entire negative CO2 emission gas...
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In-service measurement of the small wind turbine test stand for structural health monitoring
PublicationThis paper presents the research activity performed on a Small Wind Turbine (SWT) test stand. Commercially available turbine was modified towards incorporation of the sensors system for condition monitoring. Installed sensors measure angular shaft position, torque applied from the wind loads, vibration accelerations and last but not least rotational speed. All gathered data are then transferred and processed in Test.Lab by means...
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Excavation induced cast iron pipeline failure – a numerical study
PublicationNumerical study on impact of an unsecured excavation on an underground pipeline. Analysis focused on investigation of pipeline displacement generated by soil movement caused by excavation and heavy traffic. Numerical calculations and soil parameter sensitivity analysis based on Finite Element Method. Some comparisons of results with real-life failure cases.
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Probabilistic Methods in Reliability Assessment of Engineering Lightweight Structures
PublicationThe paper considers the probability-based analysis of structural safety measures. Two different numerical examples of representative lightweight structures are considered – a submerged truss tower supporting an offshore platform, and an overhead power line support truss tower. On the basis of these examples, the importance of a motivated selection of analysis method and a proper choice of the number of important variables is shown....
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An facile Fortran-95 algorithm to simulate complex instabilities in three-dimensional hyperbolic systems
Open Research DataIt is well know that the simulation of fractional systems is a difficult task from all points of view. In particular, the computer implementation of numerical algorithms to simulate fractional systems of partial differential equations in three dimensions is a hard task which has no been solved satisfactorily. Here, we provide a Fortran-95 code to solve...
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Study on deformed steel columns subjected to impact load due to soft-storey failure in buildings during earthquakes
PublicationThe so called soft-storey failure is one of the most typical types of damage induced in buildings as the result of earthquake excitation. It has been observed during ground motions that the failure of an upper soft storey of a structure results in large vertical impact load acting on the lower floors. If the resistance of the structural members of the lower storeys is not sufficient it may further lead to progressive collapse of...
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Analytical Steady-State Model of the Pipeline Flow Process
PublicationThe paper addresses the issue of modeling the flow process in transmission pipelines. A base model used for numerical simulation is introduced. Under certain assumptions concerning steady state analysis, the differential equations describing the process are solved analytically for two cases: zero and nonzero inclination angle α. These equations describe a constant flow rate and a corresponding distribution of the pressure along...
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O modelowaniu numerycznym dźwigarów zespolonych
PublicationThe paper is a general review of theoretical problems and corresponding numerical procedures actually available in commercial engineering software. Several possibilities of numerical simulation for composite girders are presented. Effectivity of meshing is showed on the simple example. Finally several examples of structural numeric models for real bridges are included. In the author's opinion, presented available procedures for...
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Probabilistic sensitivity of limit states of structures : The Monte Carlo simulation
PublicationThe main issue of the paper is the probabilistic sensitivity of the limit states of structures with respect to selected input design variables. Attempt to the problem is done by the dedicated Monte Carlo simulation procedure. Basic design variables are random variables of given probability distributions, presented in the form of random numbers. Uni-parametrical increment of the dominant basic variable (basic variables) is done,...
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ANALYSIS OF IMPACT of SHIP model parameters on changes of control quality index in ship dynamic positioning system
PublicationIn this work there is presented an analysis of impact of ship model parameters on changes of control quality index in a ship dynamic positioning system designed with the use of a backstepping adaptive controller. Assessment of the impact of ship model parameters was performed on the basis of Pareto-Lorentz curves and ABC method in order to determine sets of the parameters which have either crucial, moderate or low impact on objective...
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Numerical methods for the assessment of bridge safety barriers
PublicationThe paper presents a numerical study of the bus crash test for bridge safety barriers. The analysis is conducted with the use of explicit code LS-DYNA. The problem of hourglass effect in shell elements is discussed. The simulations of bus impact against the barrier show that the analyzed barrier withstands the impact forces and restrains the bus trajectory to the bridge road.
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Experimentation, material modelling and simulation of bonded joints with a flexible adhesive
PublicationThe paper deals with material parameters identification of a flexible adhesive and the numerical simulation of its behaviour in a single lap bonded joint. The material modelling was based on the simple shear and tensile-shear laboratory tests of the bonded joints made of thin aluminium and polyurethane plates with the flexible adhesive Terostat MS 9360 manufactured by Henkel AG & Co. The adhesive was considered as a hyperelastic...
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PROBLEMS OF THE STARTING AND OPERATING OF HYDRAULIC COMPONENTS AND SYSTEMS IN LOW AMBIENT TEMPERATURE (PART IV) MODELLING THE HEATING PROCESS AND DETERMINING THE SERVICEABILITY OF HYDRAULIC COMPONENTS DURING THE STARTING-UP IN LOW AMBIENT TEMPERATURE
PublicationDesigners of hydraulically driven machines and devices are obliged to ensure during design process their high service life with taking into account their operational conditions. Some of the machines may be started in low ambient temperature and even in thermal shock conditions (due to delivering hot working medium to cold components). In order to put such devices into operation appropriate investigations, including experimental...
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How much a geometrical model of a honeycomb seal can be simpli ed in the CFD calculation
PublicationThis paper presents the inuence of geometry simplication on the results obtained in the computational fluid dynamics simulation. The subject of simulation was part of the honeycomb seal located at the inlet to high pressure part of a steam turbine. There were three different geometrical models assumed in the calculations. First one was two-dimensional case and two others were three dimensional, one with the radius of curvature...
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Hydrodynamic reanalysis of water temperature and salinity in the Baltic Sea using the PM3D model
Open Research DataThe dataset contains the results of numerical modeling of water temperature and salinity in the Baltic Sea since 1998. A long-term reanalysis was performed using the three-dimensional hydrodynamic model PM3D (Kowalewski and Kowalewska-Kalkowska, 2017), a new version of the M3D model (Kowalewski, 1997). A numerical dynamic-thermodynamic model of sea...
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GPU-Accelerated Finite-Element Matrix Generation for Lossless, Lossy, and Tensor Media [EM Programmer's Notebook]
PublicationThis paper presents an optimization approach for limiting memory requirements and enhancing the performance of GPU-accelerated finite-element matrix generation applied in the implementation of the higher-order finite-element method (FEM). It emphasizes the details of the implementation of the matrix-generation algorithm for the simulation of electromagnetic wave propagation in lossless, lossy, and tensor media. Moreover, the impact...
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Numerical Modeling of Water and Ice Dynamics for Analysis of Flow Around the Kiezmark Bridge Piers
PublicationThis paper presents the results of a numerical model study on the effect of ice on the proposed bridge piers in the Vistula River outlet and its effect on flow conditions in the river. The model DynaRICE is used in this study, which is a two-dimensional hydro-ice dynamic numerical model developed for dynamic ice transport and jamming in rivers. To simulate river hydrodynamics in the vicinity of the bridge piers, 2-dimensional numerical...
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Hydrodynamic reanalysis of currents in the Baltic Sea using the PM3D model
Open Research DataThe dataset contains the results of numerical modeling of currents in the Baltic Sea since 1998. A long-term reanalysis was performed using a three-dimensional hydrodynamic model PM3D (Kowalewski and Kowalewska-Kalkowska, 2017), a new version of the M3D model (Kowalewski, 1997).
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ON ESTIMATION OF OCCUPANT SAFETY IN VEHICULAR CRASHES INTO ROADSIDE OBSTACLES USING NON-LINEAR DYNAMIC ANALYSIS
PublicationThe article describes a comparison of two general methods of occupants safety estimation based on a numerical examples. The so-called direct method is mainly based on the Head Injury Criterion of a crash test dummy in a vehicle with passive safety system while the indirect method uses a European standards approach to estimate impact severity level. Numerical simulations in LS-DYNA have been conducted.