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Search results for: NON-LINEAR STATIC ANALYSES
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A Method of Assessment of the Liquid Sloshing Impact on Ship Transverse Stability
PublicationLiquid sloshing phenomenon taking place in partly filled ships? tanks directly affects the stability of a vessel. However, only static calculations are carried out onboard ships nowadays and static transfer of liquid weight is taken into account in the course of routine stability calculation. The paper is focused on a dynamic heeling moment due to liquid sloshing in tanks onboard ships. The set of numerical simulations of liquid...
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Effects of Deck-Abutment Pounding on the Seismic Fragility Curves of Box-Girder Highway Bridges
PublicationEarthquake-induced pounding in bridges is a complex contact phenomenon in which the dynamic responses of structures, including collisions between deck and abutments, are strongly related to structural properties and earthquake excitation. The goal of this study is to develop and compare the seismic fragility curves of overall system and individual components of regular and irregular box-girder highway bridges in two cases: with...
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Importance of sign conventions on analytical solutions to the wave-induced cyclic response of a poro-elastic seabed
PublicationThis paper discusses the influence of different sign conventions for strains and stresses, i.e. the solid mechanics sign convention and the soil mechanics sign convention, on the form of governing partial differential equations (the static equilibrium equations and the continuity equation) used to describe the wave-induced cyclic response of a poro-elastic seabed due to propagation of a sinusoidal surface water-wave. Some selected...
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Balance errors generated by numerical diffusion in the solution of non-linear open channel flow equations
PublicationThe paper concerns the untypical aspect of application of the dissipative numerical methods to solve nonlinear hyperbolic partial differential equations used in open channel hydraulics. It is shown that in some cases the numerical diffusion generated by the applied method of solution produces not only inaccurate solution but as well as a balance error. This error may occur even for an equation written in the conservative form not...
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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.
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Nieliniowy model matematyczny transformatora trójfazowego = Non-linear mathematical model of a three-phase transformer
PublicationPrzedstawiono model transformatora trójfazowego o rdzeniu trójkolumnowym, który zawiera układ rów-nań opisujących obwód magnetyczny oraz oddzielnie układ równań obwodu elektrycznego. Wydzielenie re-luktancji elementów rdzenia umożliwia uwzględnienie zmian względnej przenikalności magnetycznej w funkcji bieżącej wartości strumienia w rdzeniu. Re-luktancje odpowiadające strumieniom rozproszenia obliczono wg zasad klasycznych. Funkcję...
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Analytical and experimental determination of parameters for the non-linear viscoelastic model of earthquake-induced structural pounding
PublicationNieliniowy model lepko-sprężysty umożliwia dokładną symulację siły zderzenia w czasie oraz symulację odpowiedzi konstrukcji podatnej na zderzanie podczas trzęsień ziemi. Jednym z celów niniejszego artykułu jest wyprowadzenie wzoru na zależność pomiędzy liczbą tłumienia zderzenia (parametr wspomnianego modelu), a współczynnikiem odbicia. Kolejnym celem jest wyznaczenie zakresu wartości współczynników odbicia oraz współczynników...
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Application of the Murnaghan model in analysis of non-linear elastic material properties of pvc-coated fabric
PublicationW pracy omówiono proces identyfikacji parametrów materiałowych dla wybranej tkaniny technicznej typu Panama. Zaproponowano metodę identyfikacji nieliniowo sprężystych właściwości tkaniny Panama dla modelu Murnaghan'a. Określono zakres stosowalności nieliniowo sprężystych parametrów, w oparciu o doraźną wytrzymałości tkaniny na rozciąganie, która poddana redukcji określa tzw. wytrzymałość długoterminową. Opisano doświadczenia niezbędne...
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ADT in mammography
PublicationWe discuss limitations of the known methods of IR imaging in diagnostics of breast cancer. In conclusion we show that for practical reasons one requires new approaches because the known methods based on simple observation of external temperature distribution are not fully effective. Even advanced pattern recognition could not help too much for static images. We ask the question: may active dynamic thermography, known in nondestructive...
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The new version of contact-less method for localisation of catenary contact wire – theoretical assumption
PublicationThis article presents the theoretical basic of a new version of contact-less method for localising the catenary contact wires, using the advanced video techniques and image analysis. So far, contact line diagnostic systems exploited nowadays uses the contact measuring methods with special design current collector. This solutions make it impossible to measure the contact line geometry in a static way. The proposed measurement method...
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Effect of bio-based components on the chemical structure, thermal stability and mechanical properties of green thermoplastic polyurethane elastomers
PublicationIt seems to be obvious that conditions changes during polyols synthesis have impact on the polyols properties. Even the chemical formula is the same or similar, physicochemical properties and also molecular weight of polyols might be different and are significant in term of future polyurethanes properties and processing. In this work, fully bio-based poly(propylene succinate)s synthesized at different temperature conditions were...
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A novel sandwich footbridge - Practical application of laminated composites in bridge design and in situ measurements of static response
PublicationA novel sandwich composite footbridge is presented in the paper, as an example of practical application of laminated composites in civil engineering. The in situ static load tests of the footbridge before its acceptation for exploitation are shown and discussed. The results are compared with the corresponding ones from a numerical equivalent single layer model of the sandwich structure created within the framework of finite element...
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A non-quasi-static-signal MOSFET model for radio and microware frequencies including spreading gate resistances and capacitaces.
PublicationZaprezentowano nowy, spójny fizycznie nie-quasi-statyczny model małosygnałowy tranzystora MOS słuszny od 0 Hz aż do częstotliwości mikrofalowych. Scharakteryzowano właściwości nowego czterokońcówkowego modelu. Model został zweryfikowany eksperymentalnie aż do częstotliwości 27 GHz.
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The significance of proximity in cluster initiatives
PublicationPurpose – The main aim of this paper is to analyse relations between geographical and competence proximity and development of cooperation in cluster initiatives. Design/methodology/approach – The research was based on an original theoretical concept referring to the trajectory of development of cooperative relations in cluster initiatives. The research was carried out in mid-2017, in four purposefully selected clusterinitiatives....
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Measurements of displacement and acceleration of the railway bridge at km 333-254 of the Vilnius - Klaipeda railway line
PublicationThe purpose of this work is to perform a report of static and dynamic test realized on the bridge at km 333-254 of the Vilnius - Klaipeda railway line over the Salantas River in Kūlupėnų.
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Method to solve the non-linear systems of equations for steady gradually varied flow in open channel network.
PublicationW artykule omówiono rozwiązanie systemu równań nieliniowych opisujacych przepływ ustalony wolnozmienny w sieci kanałów otwartych. Niewiadomymi są glębokości w poszczególnych przekrojach oraz natężenia przepływów w poszczególnych gałęziach systemu. Układ musi być rozwiązywany iteracyjnie. Klasyczne metody Picarda i Newtona mogą okazać się nieskuteczne ze względu na oscylacje rozwiązania w kolejnych iteracjach i związany z tym brak...
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Analysis of the possibility of determining the general characteristics using the operational data of a vehicle engine
PublicationThe paper presents an analysis of the possibility of determining the general characteristics using the operational data of an engine of refuse collection vehicle. Data acquisition was done by reading information from the CAN network using FMS standard (Fleet Management System), which is widely used in heavy duty vehicles since year 2002. The paper presents the analysis of the expected measurement uncertainties resulting from the...
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Prediction of Pile Shaft Capacity in Tension Based on Some Direct CPT Methods—Vistula Marshland Test Site
PublicationThis paper presents different CPT methodologies for the prediction of the pile shaft resistance in tension on the example of three reference screw piles of the Jazowa test site in Poland. The shaft capacity was estimated based on the cone resistance, sleeve friction and CPT excess pore water pressure. Three piles with diameter 0.4 m and the length varied from 8 m to 14.6 m were subjected to static load tests in tension. Their...
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Comparative Analysis of Reactive Power Compensation Devices in a Real Electric Substation
PublicationA constant worldwide growing load stress over a power system compelled the practice of a reactive power injection to ensure an efficient power network. For this purpose, multiple technologies exist in the knowledge market out of which this paper emphasizes the usage of the flexible alternating current transmission system (FACTS) and presents a comparative study of the static var compensator (SVC) with the static synchronous compensator...
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Synergistic Effects of Bitumen Plasticization and Microwave Treatment on Short-Term Devulcanization of Ground Tire Rubber
PublicationGround tire rubber (GTR) was mechano-chemically modified with road bitumen 160/220 and subsequently treated using a microwave radiation. The combined impact of bitumen 160/220 content and microwave treatment on short-term devulcanization of GTR was studied by thermal camera, wavelength dispersive X-ray fluorescence spectrometry (WD-XRF), static headspace, and gas chromatography-mass spectrometry (SHS-GC-MS), thermogravimetric analysis...
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Interactions using passive optical proximity detector
PublicationIn this paper we evaluated the possible application of a passive, optical sensor as an interface for human-smart glasses interactions. The designed proximity sensor is composed of set of photodiodes and the appropriate hardware and software components. First, experiments were performed for the estimations of such parameters as distance to an object, its width and velocity. Achieved results were satisfactory. Therefore, next, a...
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Analytical expression between the impact damping ratio and the coefficient of restitution in the non-linear viscoelastic model of structural pounding
PublicationWyniki wcześniejszych badań pokazują, iż nieliniowy model lepko-sprężysty zderzeń konstrukcji budowlanych podczas trzęsień ziemi najdokładniej symuluje siłę zderzenia w czasie kontaktu oraz odpowiedź konstrukcji. Celem niniejszego artykułu jest wyprowadzenie wzoru na zależność pomiędzy liczbą tłumienia zderzenia (parametr wspomnianego modelu) a współczynnikiem odbicia, który jest parametrem często stosowanym i analizowanym w literaturze....
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Prediction of pile shaft capacity in tension based on some direct CPT methods – Vistula Marshland test site
PublicationThis paper presents different CPT methodologies for the prediction of the pile shaft resistance in tension on the example of three reference screw piles of the Jazowa test site in Poland. The shaft capacity was estimated based on the cone resistance, sleeve friction and CPT excess pore water pressure. Three piles with a diameter of 0.4 m and the length...
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Load Tests of the Movable Footbridge Over the Port Canal in Ustka
PublicationThe paper presents the acceptance tests carried out on the open footbridge over the port canal in the Port of Ustka. The steel footbridge construction is created by a single pylon to which a movable truss span is suspended with a theoretical span of 52.3 m. The studies about load test of the object included static and dynamic extortion and measurements. In static tests the ballast was of pallets with concrete blocks. Dynamic studies...
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The use of the static thermography in monitoring flap perfusion in breast reconstruction with TRAM flap
PublicationThis paper shows results of the static thermography for intraoperative and postoperative imaging of TRAM flap perfusion. The results were compared with the clinical examination of flap perfusion. The study was conducted on a group of 38 female patients who underwent breast reconstruction.
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Static Shunt PE Voltage-Quality Controllers
PublicationThis chapter focuses on power electronics (PE)-based solutions used in distribution networks for reduction of supply-voltage-quality deterioration, from long interruptions to the harmonics. Various PE devices and their combinations are addressed for particular or a range of voltage disturbances. A particular solution is applied taking into account demands for voltage quality and network configuration. In general, there are three...
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Adaptive Hyperparameter Tuning within Neural Network-based Efficient Global Optimization
PublicationIn this paper, adaptive hyperparameter optimization (HPO) strategies within the efficient global optimization (EGO) with neural network (NN)-based prediction and uncertainty (EGONN) algorithm are proposed. These strategies utilize Bayesian optimization and multiarmed bandit optimization to tune HPs during the sequential sampling process either every iteration (HPO-1itr) or every five iterations (HPO-5itr). Through experiments using...
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Centrifugal magnetic fluid seals
PublicationSeals perform an important and at times overlooked function in a lubricant system. They prevent or minimize the movement of the lubricant between two surfaces and also minimize the level of contamination in the system. Seals are divided into static and dynamic types. Static seals operate in systems where the mating surfaces do not move relative to each other. In contrast, dynamic seals operate under conditions where the mating surfaces...
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Agent System for Managing Distributed Mobile Interactive Documents in Knowledge-Based Organizations
PublicationThe MIND architecture of distributed mobile interactive document is a new processing model defined to facilitate obtaining a proper solution in knowledge processes carried out by knowledge-based organizations. Such organizations have an established structure that defines document templates and knowledge process. The aim of the MIND architecture is to change the static document to mobile agents, which are designed to implement the...
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Pore Water Pressure Development in Soft Soil due to Installation and Loading of Controlled Modulus Columns
PublicationExcess pore water pressure (EPWP) development and decay due to the installation and static loading tests of controlled modulus columns (CMC) in soft soil was measured with piezometers equipped with low air entry (LAE) filters and a piezocone (CPTU) equipped with a high air entry (HAE) filter. The HAE filter allows for detailed detection of EPWP in short time intervals during construction of CMC. The influence zone due to the installation...
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Adaptive Identification of Underwater Acoustic Channel with a Mix of Static and Time-Varying Parameters
PublicationWe consider the problem of identification of communication channels with a mix of static and time-varying parameters. Such scenarios are typical, among others, in underwater acoustics. In this paper, we further develop adaptive algorithms built on the local basis function (LBF) principle resulting in excellent performance when identifying time-varying systems. The main drawback of an LBF algorithm is its high complexity. The subsequently...
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Local and global response of sandwich beams made of GFRP facings and PET foam core in three point bending test
PublicationIn the paper behaviour of laminated sandwich beams (FRP face sheet – PET foam core – FRP face sheet) subjected to three point bending is studied. The paper aim is to find practical descriptions enabling effective and accurate estimation of the elastic response, damage and failure of the beams, basing on experiments and static calculations. Therefore a number of tests are described, that were done on laminated coupons and foam specimens...
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Non-linear FEM analysis of earthquake-induced pounding between the main building and the stairway tower of the Olive View Hospital
PublicationCelem artykułu jest dokładna, trójwymiarowa analiza MES dotycząca zderzeń pomiędzy budynkiem głównym a konstrukcją wolnostojącej klatki schodowej szpitala Olive View podczas trzęsienia ziemi San Fernando w roku 1971. Wyniki analizy pokazują, iż kolizje mogą prowadzić do znacznego wzrostu odpowiedzi lżejszej konstrukcji klatki schodowej, powodować uszkodzenia w miejscach kontaktu oraz potęgować uszkodzenia u podstawy tej budowli....
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Comparison of tuning procedures based on evolutionary algorithm for multi-region fuzzy-logic PID controller for non-linear plant
PublicationThe paper presents a comparison of tuning procedures for a multi-region fuzzy-logic controller used for nonlinear process control. This controller is composed of local PID controllers and fuzzy-logic mechanism that aggregates local control signals. Three off-line tuning procedures are presented. The first one focuses on separate tuning of local PID controllers gains in the case when the parameters of membership functions of fuzzy-logic...
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Circular saw vibrations or dynamics of the spindle
PublicationSawing of wood with circular saws is a typical example of cutting with multi-blade tools. In that kind of cutting, theposition accuracy of following tool blades is a crucial factor which affects the cutting process and machining final effects.Position tooth errors may cause deterioration in cutting conditions, changes in loads of individual teeth and the tool as a whole,and also a decrease in accuracy and surface quality after...
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Numerical analysis by FEM and analytical study of the dynamic thermal behavior of hollow bricks with different cavity concentration
PublicationThis paper presents the investigation results on the influence of the cavity concentration in hollow bricks on static and dynamic thermal parameters: a time lag, a decrement factor, an equivalent thermal diffusivity (ETD) and an equivalent thermal conductivity (ETC). The dynamic thermal behavior of hollow bricks is studied with an optimized cavity shape to reduce the intensity of radiation and convective heat exchange. The thermal...
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Visualization of a lifeboat motion during lowering along ship’s side
PublicationThis paper presents description of a computer program for motion visualization of a lifeboat lowered along ship’s side. The program is a post-processor which reads results of numerical calculations of simulated objects’ motions. The data is used to create scene composed of 3D surfaces to visualize mutual spatial positions of a lifeboat, ship’s side and water waving surface. Since the numerical data contain description of a simulation...
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NEW DESIGNS OF CENTRIFUGAL MAGNETIC FLUID SEALS FOR ROTATING SHAFTS IN MARINE TECHNOLOGY
PublicationThe centrifugal magnetic fluid seals have important advantage over the conventional centrifugal seals. They maintain very good sealing capacity at static, medium and high speeds of shaft rotation, with the increased seal lifetime, and minimum torque and static friction. These seals are particularly useful in cases when the angular shaft velocity varies and sometimes decreases to nearly or exactly zero, such as in flywheel applications,...
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Three-dimensional mapping for data collected using variable stereo baseline
PublicationThe paper describes a system of 3D mapping of data collected with due regard for variable baseline. This solution constitute an extension to a VisRobot sub-system developed as a subsystem, necessary for implementing the generic idea of using mobile robots to explore an indoor static environment. This subsystem is to acquire stereo images, calculate the depth in the images and construct the sought 3D map. Stereo images are obtained...
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Numerical analysis by FEM and analytical study of the dynamic thermal behavior of hollow bricks with different cavity concentration
PublicationThis paper presents the investigation results on the influence of the cavity concentration in hollow bricks on static and dynamic thermal parameters: a time lag, a decrement factor, an equivalent thermal diffusivity (ETD) and an equivalent thermal conductivity (ETC). The dynamic thermal behavior of hollow bricks is studied with an optimized cavity shape to reduce the intensity of radiation and convective heat exchange. The thermal...
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Displacement measurements during load testing of railway arch bridge
PublicationThe paper discusses issues concerning load tests carried out on a twin-track, arch railway bridge over the Martwa Wisla river in Gdansk. Currently, it is the bridge with the longest span in its class in Poland. The load-bearing structure consists of three no-hinge arches and an orthotropic deck suspended from them. The studies of the structure assumed the performing of static and dynamic tests. The paper presents the method for...
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High-efficiency hybrid PV-TEG system with intelligent control to harvest maximum energy under various non-static operating conditions
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Impact of power electronic Var compensators installed in certain grid points on the voltage failure
PublicationThe article presents the test results of the various types of static compensators FACTS models in the power system. The basic case, which was analyzed, it was behavior of compensators which are installed in select points of the system during voltage failure. The article presents selected results of studies conducted as part of a work [2].
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Mode vibrations of plates – experimental analysis
PublicationIn this paper results of the square MDF plate and circular saw blades examination with the use of the harmonic method to static identification of resonant frequencies and shapes of mode vibrations are presented. Obtained results reveled that for circular saws with large holes in a saw blade appeared two resonant frequencies for the same nodal number.
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<title>Non-linear glasses and metaglasses for photonics, a review: Part II. Kerr nonlinearity and metaglasses of positive and negative refraction</title>
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Control of the bridge span vibration with high coefficient passive damper. Theoretical consideration and application
PublicationThe research was carried out due to the problem of vibration on the lively pedestrian drawbridge across the Motlawa River in the city of Gdansk. In the design stage, the main span of the footbridge showed unfavorable dynamic properties, which may create a comfort problem for pedestrians. The first vertical bending eigenfrequency was recognized as 1.64 Hz. The original design of the footbridge was equipped with a driving cylinder...
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Measurements of Path Loss in Off-Body Channels in Indoor Environments
PublicationThis paper presents a measurements of the path loss for validation of a statistical model for off-body radio channels in an indoor multipath environment, which considers the distance dependent mean path loss, and describes body shadowing and fast fading components in a statistical way. The measurement equipment and propagation indoor environment have been presented. Two different bodies and five static and two walking scenarios...
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Static and dynamic concrete calculations: Breakable aggregates in DEM model
PublicationThe paper deals with the calculations of a 3-point bending beam under static and dynamic loads. The real microstructure was obtained from laboratory tests using micro-tomography images. The quasi-static results were compared directly with experimental data at both macro and micro levels. Subsequently, higher strain rates were applied to investigate dynamic effects. The study focused on the influence of dynamic loading on the macroscopic...
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Assembling and testing of quasi-static hybrid piezoelectric motor based on electroactive lubrication principle
PublicationThe presented paper concerns a novel concept of hybrid piezoelectric motor based on electroactive lubrication principle. Its structure is combined of quasi-static and resonance piezoelectric actuators, synchronizing their work to generate the rotary movement. The hybrid motor topology is compared to the existing piezoelectric motors, regarding its field of applications in embedded systems with very high security requirements. The...
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Morphology of damage inflicted on brittle polymer in lubricated contact under cyclic static load
PublicationIn this article morphology of damage inflicted on the polymethylmethacrylate (PMMA) plate in static point lubricated contact with a ball made of five different materials under cyclic normal load has been presented. It is argued that the counterface material and lubricating film play an important role in the damage process and the extent of damage inflicted in the PMMA plate.