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Search results for: FEMTOSECOND PHENOMENA
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Cavitation Erosion Resistance of Austenitic Stainless Steel after Glow-Discharge Nitriding Process
PublicationThis paper presents investigation of cavitation erosion resistance of nitrided austenitic stainless steel X5CrNi18-10. The diffusion layers were produced by using different parameters of atmosphere (N2:H2). The microstructure, chemical composition and phase identification of the modified layer were examined using scanning electron microscopy, glow-discharge optical emission spectrometer and X-ray diffractometry, respectively. Cavitation...
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Materials Design for the Titanium Scaffold Based Implant
PublicationThe main objective of here presented research is a design the scaffold/porous titanium(Ti) alloy based composite material demonstrating better biocompatibility, longer lifetime andbioactivity behaviour for load-bearing implants. The development of such material is proposed bymaking a number of consecutive tasks. Modelling the mechanical, biomechanical and biologicalbehavior of porous titanium structure and an elaboration of results...
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Optimization of Self-Organized TiO2 Nanotube Geometry on Ti and Ti Alloys Using Fuzzy Logic Reasoning
PublicationThe geometry of self-organized TiO2 nanotubes, obtained by electrochemicalanodization, has been determined by using fuzzy reasoning approach. The efficiency of TiO2nanotubular layer in biomedical applications depends on geometry and available surface area ofnanotubes, which can be determined by their diameter and length. The structure of nanotubesdepends on processing parameters of electrochemical anodization, like applied potential,anodization...
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Formation of High Corrosion Resistant Nanotubular Layers on TitaniumAlloy Ti13Nb13Zr
PublicationThis paper presents results of oxidation tests and corrosion investigations of titanium alloy Ti13Nb13Zr performed at different conditions. The oxide layers have been formed by electrochemical method in 2M H3PO4 + 0.3% HF solution for 30 min. and 1 h at 20 V constantvoltage. The corrosion tests have been made by potentiodynamic method in Ringer`s solution at pH ranged between 3 and 7. It has been shown that the nano-oxide films,...
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Effects of Laser Remelting at Cryogenic Conditions on Microstructure and Wear Resistance of the Ti6Al4V Alloy Applied in Medicine
PublicationThe titanium and its alloys can be subjected to surface treatment, including laser treatment. In this work a new laser treatment at cryogenic conditions of Ti6Al4V alloy has been described. The work has been aimed at establishing whether such surface treatment could be suitable for implants working under wear in biological corrosive environment. The remelting has been made with the use of CO2 continuous work laser at laser power...
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Environmental Degradation of Engineering Materials & Materials Engineering and Technologies
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Modelling of the Heat Flux Density Distribution for Laser Beam Welding
PublicationGreat interest of the laser beam welding in industry is a new theoretical task, making planning the welding procedure specification and the quality control of welded joints easier. Estimating and calculating the dimensions of a weld pool and temperature distribution near weld mainly concern heat source modelling. In the presented work calculations of welding pool shape and thermal field for cylindrical-powered-normally model of...
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Determination of Failure Causes of a Steam Turbine Casing
PublicationThe paper presents results of research and failure analysis undertaken to determine failure causes of a steam turbine casing. After 130,000 hours of service the crack in a outer shell of the turbine casing was found. The inner shell of the casing was made of cast steel grade G21CrMoV5-7, and the outer shell of grade G20CrMo4-5. Following research were performed in order to determine causes of the casing failure: chemical analysis;...
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The Effect of Welding Conditions on Diffusible Hydrogen Content in Deposited Metal
PublicationThe article presents the results of a literature survey and preliminary tests which set out effects of welding conditions on the amount of diffusible hydrogen in deposited metal. Experiments were conducted by using rutile coated electrodes which generate high contents of diffusible hydrogen in deposited metal. The amount of diffusible hydrogen was determined by a glycerin test.Eleven factors were considered: the electrode angle,...
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Degradation of Gel-Coat Layer in Glass/Polyester Laminate in Seawater Environment
PublicationGlass/polyester laminate coated with gelcoat layer of different thickness 0,5; 1,5; 3 mm was studied in terms of blistering behaviour and water sorption in hot water environment. Blistering was found to be accelerated for thin (0,5 mm) gel-coat layer compared to the thick (1,5; 3 mm), however no significant difference in blistering behaviour was observed between the laminates with gel-coat thickness 1,5 and 3 mm which may suggest...
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Formation of Porous Structure of the Metallic Materials Used on Bone Implants
PublicationResearch on improvement of structure and fabrication methods of the bone implants are carried out for many years. Research are aimed to shape the structures, that will have a Young's modulus value similar to the value of the human bones Young's modulus. Depending on theporosity, Young's moduli can even be tailored to match the modulus of bone closer than solid metals can, thus reducing the problems associated with stress shielding...
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Effect of crystallization process at cryogenic conditions on the functional properties of the SUPERSTON alloy used in production the ship's propellers
PublicationThe purpose of this paper is to show results of laser treatment at cryogenic conditions of the SUPERSTON alloy used for ship's propellers. That modification process ought to bring beneficial changes of microstructure and residual stresses in the surface layer. During the laser remelting at cryogenic conditions the microstructure changes significantly. This is related to synergistic effects of the solidification rate, phase transformations...
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Underwater Welding of Duplex Stainless Steel
PublicationThe present work was conducted to assess the weldability of duplex stainless steel at underwater conditions. Interest of underwater welding of this steel grade is connected with necessity of preparing welding repair technologies for subsea pipelines widely used in offshore oil and gas industry. The GMA local cavity welding method was used in the investigations. Welded beads were performed underwater at 0.5 m depth and in the air....
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Oxidation Time Influence on the Structure of the Cobalt Base Clad Layer and Scale Morphology
PublicationZbadano wpływ czasu utleniania na mikrosrukutręi własności mechaniczne a w szczególności mikrotwardość, warstw wykonanych ze stopu kobaltu.Warstwy były wykonane za pomocą napawania plazmowego (PTA). Stop kobaltu podlegał utlenianiu w powietrzu w temperaturze 800 topni celsjusza w czasie 1, 22 i 200 godzin. w wyniku utleniania nastapiło uformowanie warstw zgorzeliny oraz nastapiły zmiany w mikrostrukturze. Zaobserwowano także zmiany...
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The Influence of Modelling Material Zones on Strains and Stresses at Weld Toe Notch
PublicationThe latest development in the field of welding technology enabled prefabrication of thin-walled sandwich structures in an industrial scale. Sandwich structures fabricated of steel, or aluminium alloy plates and stiffeners are welded with the use of hi-power CO2 lasers. Strength analysis of such structures with the use of finite element method needs proper material modelling.In this paper the material model of steel sandwich panel...
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Multi Parameter Sliding Test Result Evaluation for The Selection of Material Pair for Wear Resistant Components of a Hydraulic motor Dedicated for Use With Environmentally Friendly Working Fluids
PublicationIn the paper the method and results are presented of the testing of tribological performance of a number of hard materials available commercially. The tests consisted in unidirectional sliding with liquid lubrication. The load and velocity regime chosen were similar to a standard four-ball lubricity test with constant velocity and load increasing over time. The regime was modified in such a way that over the initial part of the...
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Influence of Spatial Structures of 316L Stainless Steel on Its Cavitation Erosion Resistance
PublicationCavitation erosion performance of modified macroscopic internal structure 316L stainless steel was investigated. The samples processed by means of SLM method were subjected to cavitation erosion test. The scanning electron microscope Philips 30/ESEM was used to examine morphology of eroded surface.
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Effect of Some Sulphur Additives on The Degradation of 9Cr-1Mo Steel After Its 10 Years Service in The CCR Platforming Unit
PublicationThe work shows the results of the tests of 9Cr-1Mo steel, which was for 10 years operated in the CCR platforming unit in Group Lotos SA in Gdańsk, and then in the laboratory was sulphidised during 166 h at a temperature of 600 °C. Sulphidation was performed in a mixture of H2-H2S gases at the vapour pressure of sulphur 4.1·10-14 atm, so the order of magnitude of vapour pressure was less than that of the dissociation pressure of...
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Evaluation of Wear Resistance of Ti alloys used for elements friction of knee endoprosthesis
PublicationThe paper presents research results of resistance to abrasive wear of titanium alloys: Ti6Al4V (commonly used) and Til3Nb13Zr (alloy of new generation) in association with polyethylene (UHMW-PE) predisposed for elements on pair of the knee endoprosthesis. The results were analysed from the point of possibility of an use of new generation titanium alloys as components of such implants. The tests of resistance to abrasive wear of...
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Identification of the Inertia of Masses Flowing Water through the Pipes in Water Power Plants
PublicationW artykule przedstawiono sposób identyfikacji stałej czasowej reprezentującej bezwładność mas przepływającej wody w systemie rurociągów, w elektrowni wodnej. Przedstawiono strukturę modelu układu regulacji prędkości kątowej wykorzystywanego w procesie identyfikacji oraz przeprowadzono badania skuteczności działania metody w środowisku Matlab-Simulink. Opisano najistotniejsze wnioski wynikające z przeprowadzonych badań symulacyjnych.
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Selected problems of navigation of educational mobile robot
PublicationW artykule przedstawiono ideę sterowania układem autonomicznego robota mobilnego skonstruowanego do celów edukacyjnych. Opisano strukturę mechaniczną układu, układy sensorów oraz zakres możliwości wynikających z działania oprogramowania robota.
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The Behaviour Based Area Coverage of Unknown Environment by Autonomous Mobile Robot Using Modified ''The Way of the Ox'' Algorithm
PublicationPrzedstawiono propozycję rozwiązania zagadnienie całkowitego pokrycia terenu w układzie autonomicznego robota mobilnego. W tym celu zmodyfikowano algorytm "siewcy" oraz opracowano odpowiedni model układu, w środowisku Matlab-Simulink. Wykonano serię badań symulacyjnych, których najistotniejsze wyniki opisano w artykule.
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Localization of Mobile Robot Using Radio Waves
PublicationOpisano systemy lokalizacji robotów mobilnych wykorzystujące metody triangulacji i trilateracji, w przestrzeniach dwuwymiarowych. Zaproponowano metodę pomiaru odległości drogą radiową oraz przedstawiono uzyskane wyniki badań.
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Comparison the Accuracy of the Extrapolation Methods of the Time Phase Coincidence in Synchronization of Power Generating Units
PublicationW artykule opisano metody ekstrapolacji chwili zgodności fazowej napięć łączonych obiektów elektroenergetycznych. Przeprowadzono analizę porównawczą wybranych metod ekstrapolacji w równych warunkach pracy oraz przedstawiono najistotniejsze wyniki badań.
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Influence of type of material on performance of hydraulic components in thermal shock conditions
PublicationDuring the start-up of a hydraulic system in low ambient temperatures an incorrect operation may occur. The principles and conditions of safely operating hydraulic driven machines and devices are essential to designers and operators. For this reason the author of this article has conducted a series of tests on hydraulic components and systems in thermal shock conditions (cooled-down components were supplied with hot working medium)....
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Using River Formation Dynamics Algorithm in Mobile Robot Navigation
PublicationRiver Formation Dynamics is a heuristic optimization algorithm based on the manner, in which drops of water form the river bed. The idea is to imitate the movement of drops on the edges between given nodes thus performing a search based on their height, which is modified through the mechanism of soil erosion and sediment deposition. In this way decreasing gradients are constructed, and these are followed by subsequent drops to...
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Behavior Based Complete Coverage Task of Unknown Area by an Autonomous Mobile Robot SCORPION with Static Obstacles in Environment
PublicationIn the paper the behavior based control system of an autonomous mobile robot SCORPION is presented to execute the one of the most difficult navigation task, which is the complete coverage task of unknown area with static obstacles in the environment. The main principle assumed to design control system was that the robot should cover all area only once, if it possible, to optimize the length of path and energy consumption. All commercial...
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Studies of the Modelling Accuracy of Steam Turbine Control Systems for Diagnostic Tests of Automatic Synchronizers
PublicationOne of the important factors that affect the reliable operation of the power system and the rapid restitution after disaster is a quick and effective combining synchronous electric power facilities to operate in parallel. Hence, diagnostics of automatic synchronizers at every stage of their life, from building a prototype, through the whole life, until removing such devices from the operation, is an extremely important and responsible...
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The Optimal Spindle Speed Map for Reduction of Chatter Vibration During Milling of Bow Thruster Blade
PublicationW artykule przedstwiono przykład wykorzystania procedury tworzenia mapy optymalnych prędkosci obrotowych w celu ograniczenia drgań samowzbudnych podczas frezowania płata śruby okrętowego steru strumieniowego.
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Mathematical Models of Control Systems of Angular Speed of Steam Turbines for Diagnostic Tests of Automatic and Mechatronic Devices
PublicationAccurate modeling of physical processes of many automatics and mechatronics systems is often necessity. In power system such a process is control of angular velocity of power objects during connection to operation in parallel. This process is extremely dynamic. For this reason response of control system depends from changes of many physical parameters (temperature, pressure and flow of the medium, etc.). Precision modeling influences...
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Port-Based Modelling of Distributed-Lumped Parameter Systems
PublicationThere in the paper is presented an uniform, port-based approach to modelling of both lumped and distributed parameter systems. Port-based model of the distributed system has been defined by application of bond graph methodology and distributed transfer function method (DTFM). The approach proposed combines versatility of port-based modelling and accuracy of distributed transfer function method. The concise representation of lumped-distributed...
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Effect of the Unit Pressure on the Selection Parameters of Intermetallic Coastings NiAl and Ni3Al after Platic Working
PublicationW artykule omówiono wpływ zgniotu na wybrane parametry warstwy międzymetalicznej NiAl i Ni3Al napawanej na stali C45 podanej obróbce plastycznej poprzez prasowanie na zimno.
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Modal Reduction and Analysis of Gyroscopic Systems
PublicationThe paper introduces the method of the modal reduction of systems that experience the Coriolis acceleration or gyroscopic effect component. In such cases corresponding system equations are non-self-adjoined. To solve the problem modal reduced model is built up for the system without Coriolis acceleration or gyroscopic effect terms. These phenomena are included by application of any lumping technique. Hence, the final reduced model...
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Analysis of Asymmetrical Rolling Process of Multilayer Plates
PublicationW niniejszej pracy przedstawiono wyniki badań numerycznych asymetrycznego procesu walcowania blach wielowarstwowych M1E-Al99,8-AlMg5. Modelowanie numeryczne procesu walcowania blach wielowarstwowych przeprowadzono w programie Forge 2D, którego obliczenia bazują na metodzie elementów skończonych. Przedstawione w pracy wyniki umożliwiły przeprowadzenie analizy procesu walcowania blach wielowarstwowych.
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Surface Roughness Model Components Created by Stereolithography Method
PublicationW pracy przedstawiono charakterystykę powierzchni elementów wykonywanych metodą stereolitografii. Opisano modele chropowatosci stosowane do opisywania powierzcni wraz z prezentacją formuł matematycznych. W oparciu o wyniki badań eksperymentalnych przeprowadzono częściową weryfikację modeli.
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Modeling and simulation of tool cycle in manufacturing cell
PublicationThe paper addresses issues concerning modeling and analysis of tool flow within a three-machine manufacturing cell used for small batch manufacturing of a definite spectrum of prismatic parts. The approach utilizes a method for job and tool allocation to work centers with limited number of machines and capacity of tool resources, based on the analysis of formalized relations: job - tool sets required. Selected tool flow control...
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Optimum Control of Gyroscopic Systems
PublicationThe problem of optimum control of transverse rotor vibrations with gyroscopic interactions has been described and solved in the paper. An integral performance index has been defined for such system in order to minimize vibration level of a chosen rotor point. For this reason, an efficient way of finding the weight coefficients of integral performance index for multi-degrees-of-freedom system with gyroscopic interactions has been...
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Modelling of Ship’s Heeling and Rolling for the Purpose of Gantry Control Improvement in the Course of Cargo Handling Operations in Sea Ports
PublicationThe paper presents two proposals of models of interaction between a ship and cargo being loaded or discharged by a gantry in port, in terms of heeling and rolling of the vessel. The main purpose of such modelling is the need for improvement of gantry control with regard to faster operations thanks to more accurate estimation of level and moment of cargo release from a gantry hook or spreader. The study may be the contribution to...
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Phase investigations of copper based CuZn38Al2MnFe alloy
PublicationW pracy przedstawiono analizę fazową mosiądzu CuZn38Al2MnFe. Wykazano, że obecność fazy Fe4Mn77Si19 powoduje kruchość stopu w teście zginania próbek.
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Influence of geotechnical conditions on damage states of Gdansk Bay Coast cliff formations
PublicationA geotechnical aspect of destruction processes of seashores was identified based on the case of erosion of Gdansk Bay Coast cliff formations. Causative factors of landslide were described in the context of natural phenomena, land development and its anthropogenic transformations. Possible directions of theoretical analysis of changes in groundwater relations were indicated.
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Synchronic digital stereophotography and photogrammetric analyses in monitoring the flow of liquids in open channels
PublicationThe authors present the results of their research into photogrammetric documents based on synchronic digital images. Examples presented in the paper indicate the value of synchronic stereophotography in registering phenomena connected with liquids. Combining synchronic stereophotography with photogrammetric methods has allowed the authors to develop an application useful for monitoring the flow of a liquid in an open channel.
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FURTHER REMARKS ON THE SURFACE VIS IMPRESSA CAUSED BY A FLUID-SOLID CONTACT
PublicationIt is well-known that, nano-mechanics should take into account not only physical phenomena occuring within the bulk but, first of all, the physical phenomena appropriate for a surface of two materials contact. The huge volume density of internal surfaces as well countours lines located within the nanomaterial results in our interest in, apart from classical form of mass, momentum and entropy transport, those modes of transportation...
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Surface Science - 2021/2022
e-Learning CoursesThe goal of the subject is the presentation of basic problems resulting from he existence of interfacebetween material objects and its surroundings. Discussion of the consequences arising from the existenceof surface energy. Analysis of possible applications of surface phenomena in technology. Understanding ofproblems and benefits resulting from decreasing dimensions of objects with the special emphasis on thesemiconductor band...
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Optical photoluminescent, and electroluminescent properties of organic solids
PublicationThis chapter discusses optical, photoluminescence and electroluminescence properties of organic materials. First, the spectral features of individual molecules and molecular solid states are analysed. Next, the excitonic processes in organic materials are discussed. The chapter reviews experimental methods leading to the determination of basic excitonic parameters. Finally, the electroluminescence phenomena in organic materials...
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Badania wstępne możliwości oceny stanu powierzchni tocznej szyn za pomocą zjawisk wibroakustycznych
PublicationW artykule przedstawiono wstępną koncepcję możliwości wykorzystania zjawisk wibroa-kustycznych w celu oceny stanu powierzchni tocznych szyn. Scharakteryzowano metodykę, zakres badań oraz wybór punktów lokalizacyjnych. Badania wstępne obejmowały pomiary drgań i hałasu na referencyjnym odcinku toru oraz na odcinku toru z wadą squat. Pomiary przeprowadzono na dwóch liniach kolejowych nr 213 Reda – Hel oraz 131 Chorzów Batory – Tczew....
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Comparison of properties of the new electro-mechanical model and circumferential model of the inductive-dynamic drive
PublicationThe article presents a new electromechanical model of inductive-dynamic drive. The model is implemented in two environments: Maxwell for analyzing electrodynamic phenomena including moving of the disc and Ansys which allows for stress analysis on the basis of the volume forces imported from Maxwell. Additionally, a model validation by comparing with the existing circumferential model was carried out.
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Employment structure by enterprise size in Poland in 2010-2014
Open Research DataMicro, small and medium-sized enterprises employ in total nearly 70% of all employees working in the corporate sector. Micro enterprises play a decisive role in this respect, accounting for nearly 40% of all employees. This dataset contains data showing the structure of the number of employees in enterprises in 2010-2014.
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Janusz Cieśliński prof. dr hab. inż.
PeopleHe was born on April 15, 1954 in Slupsk. He graduated from the Faculty of Mechanical Engineering at Gdańsk University of Technology (1978). In 1986 he received the title of Doctor, in 1997 he obtained the title of Ph.D. with habilitation, and in 2006 he received the title of Professor. He worked as head of department and vice-dean for Education at the Faculty of Mechanical Engineering for two terms (2002-2008). His research interests...
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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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Modelling of pipes conveying flowing liquid
PublicationThe paper introduces the method of modal reduction of system which consists of pipe with flowing liquid. The concept of hybrid model is proposed. The system model consists of two parts, the modal model and the finite elements model. The modal model represents linear, self-adjoined part of the system, while simple lumped technique is applied for modelling of Coriolis phenomena.