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Search results for: spring characteristic
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Effects of Addictive Substances During Pregnancy and Infancy and Their Analysis in Biological Materials
PublicationThe use of addictive substances during pregnancy is a serious social problem, not only because of effects on the health of the woman and child, but also because drug or alcohol dependency it detracts from childcare and enhances the prospect of child neglect and family breakdown. Developing additive substance abuse treatment programs for pregnant women is socially important and can help ensure the health of babies, prevent subsequent...
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Response of a steel tank during earthquakes and mining tremors - experimental investigation
PublicationCylindrical steel tanks are very popular shell structures used to store the products of chemical and petroleum industries. Any failure might have disastrous consequences, therefore their safety and reliability is essential. Earthquakes are the most dangerous and also the most unpredictable dynamic loads acting on such structures. On the other hand, mining tremors are usually considered to be less severe due to lower acceleration...
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SAWING PROCESS AS A NEW ALTERNATIVE WAY OF DETERMINING SOME WOOD PROPERTIES
PublicationCutting forces (power) could be considered from a point of view of modern fracture mechanics. The developed cutting model, derived from fracture mechanics, includes work of separation (fracture toughness) in addition to plasticity and friction, and also dullness of the cutting edge described by the cutting edge radius. Moreover, forecasting of the shear plane angle for the cutting models, broaden possibilities of energetic effects...
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Security Requirements and Controls for Incident Information Sharing in the Polish Power System
PublicationAmong the strategies of protecting information assets of the power system, sharing of information about current cybersecurity incidents between energy operators appears to be a prerequisite. Exchange of information leads to the effective detection of attacks and exploited vulnerabilities as well as the identification of countermeasures. This paper presents the results of continuation of our works on developing a secure and efficient...
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Diagnostic usefulness of granulometric analyses of chips distribution while sawing of wood
PublicationW niniejszym artykule opisano drogi transportu wiórów w procesie przecinania drewna i ich wpływ na rozdrobnienie wiórów. Przedstawiono również wyniki badań rozkładu segregacji wiórów powstających w procesie przecinania piłą o powszechnie stosowanej konstrukcji i piłą z domkniętymi rowkami wiórowymi.
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A proposal for knowledge sharing in the e-Decisional community using Decisional DNA
PublicationZaproponowano model platformy wspomagającej wymianę wiedzy w społeczeństwie decyzyjnym opartym na decyzyjnym DNA.
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Nitrogen fraction fluctuation during wastewater treatment in a multistage treatment wetland
PublicationAlthough the size of pollutants discharged to a WWTP plays an important and often underestimated role in characterizing treat ability and hence the degree of contaminant removal of wastewater. From one hend In order to obtain efficient nitrogen removal in thedenitrification process, sufficient amounts of bioavailable carbon source should be ensured bur for the other hand in TWs, particulates from the wastewater are naturally trapped...
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Linear viscoelastic modelling of damage-involved structural pounding during earthquakes
PublicationDamage-involved structural pounding during earthquakes has been recently intensively studied using different impact force models. The results of the previous studies indicate that the linear viscoelastic model is relatively simple yet accurate in modelling pounding-involved behaviour of structures during earthquakes. The only shortcoming of the model is a negative value of the pounding force occurring just before separation, which...
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The shadowing chain lemma for singular Hamiltonian systems involving strong forces
PublicationW niniejszym artykule rozważamy autonomiczny układ Hamiltonowski na płaszczyźnie z potencjałem, który ma punkt osobliwy (studnię nieskończonej głębokości) i maksimum globalne właściwe równe zero przyjmowane w dwóch różnych punktach płaszczyzny. Przy założeniu, że w otoczeniu punktu osobliwego potencjał spełnia warunek Gordona(gradient tego potencjału w otoczeniu punktu osobliwego jest tzw. silną siłą, ang. a strong force) dowodzimy...
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Knowledge Sharing and Organizational Culture Dimensions: Does Job Satisfaction Matter?
PublicationThe aim of this study is to examine how job satisfaction influences the relationship between company performance, knowledge sharing, and organizational culture, perceived through the prism of Hofstede’s cultural dimensions, controlled by company size and staff position. A survey of 910 Polish employees (mainly knowledge workers) with different roles and experiences across different industries was conducted. The data were analyzed...
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ADAPTATION OF THE ACTIVATED SLUDGE TO THE DIGESTATE LIQUORS DURING THE NITRIFICATION AND DENITRIFICATION PROCESSES
PublicationThe activated sludge process of the digestate liquors after chemical separation was conducted using a 10 L lab-scale sequencing batch reactor (SBR) and a 0.50 m3 pilotscale SBR independently (with pH control). Due to the relatively high concentration of free ammonia (FA), clear inhibitory effects of the digestate liquors on the nitrifying bacteria were observed. The adaptation of the activated sludge to the toxicity was evaluated...
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Stabilization of Solid Residues Obtained During Sewage Sludge Thermal Treatment
PublicationCurrently wastewater treatment plants are still dealing with the problem of ecological management of sewage sludge. Nowadays, thermal utilization is considered the most eco-friendly way of processing excess sludge. However, during mentioned process, fractions of ashes and dusts are generated. Such wastes, especially dusts fraction, can be potentially harmful for the environment and wastes should be stabilized before further management....
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Trajectory planning for Service Ship during emergency STS transfer operation
PublicationIn this paper trajectory for approaching during emergency STS transfer operation with oil spill is considered as a sequence of navigation manoeuvres in specific navigational environment. The designed way points - ship positions and speed are determined as reference values to support navigator in decision making during steering and to mitigate the risk of collision which mostly results from exceeding the speed limit of approaching....
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Identification of diagnostic parameter sensitivity during dynamic processes of a marine engine
PublicationChanging some parameters of the engine structure alters the emission of harmful components in the exhaust gas. This applies in particular to the damage of charge exchange system as well as fuel system and engine supercharger. These changes are much greater during the dynamic states and their accompanying transitional processes. The different sensitivity of diagnostic parameters to the same force, coming from the engine structure, but...
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Spurring the community involvement in planning - lessons from post-socialist cities
PublicationPublic participation and community involvement in planning processes is – in general – not a new topic for contemporary planners. But in many parts of the world – including the post-socialist countries like Poland or Russia – we can still face the lack of understanding of importance of proper community involvement in planning and development processes. Situation in these countries is significantly different from both highly-developed...
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Storing thermal energy from solar collectors for the needs of a detached house
PublicationThis work evaluates the possibility of meeting a single familu household's need for hot water and heat year round, using solar collectors as the sole energy sourse. The main flaw of energetic systems based on solar energy is that the energy supply is usually insufficient in winter, when it is most needed. This work is going to show thatm for a house surface of 150 m2 and base dimension of 10x10m, it is possible to supply sufficient...
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Influence of substituents in vinyl groups on reactivity of parylene during polymerization process
PublicationPraca zawiera wyniki obliczeń kwantowych wielokonfiguracyjnych i DFT mechanizmów reakcji parylenu i cząsteczek z wiązaniami podwójnymi w fazie gazowej. Zbadany został i zanalizowany wpływ podstawników w strukturach alkenów na reaktywność parylenu i alkenów.
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Application of fracture mechanics for energetic effects predictions while wood sawing
PublicationIn the classical approach, energetic effects (cutting forces and cutting power) of wood sawing process are generally calculated on the basis of the specific cutting resistance, which is in the case of wood cutting the function of more or less important factors. On the other hand, cutting forces (power) could be considered from a point of view of modern fracture mechanics. Cutting forces may be employed to determine not only toughness...
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Numerical calculations of behaviour of ship double-bottom structure during grounding
PublicationIdeą projektu CORET jest dodanie do obecnej konstrukcji dna podwójnego statku specjalnych powłok polimerowo-betonowych w celu zwiększenia odporności na rozszczelnienie podczas kolizji, czy wejścia na mieliznę. Aby poprawnie zaprojektować te bariery ochronne konieczne jest przeprowadzenie symulacji numerycznej. Tworzenie modelu numerycznego konstrukcji podczas kolizji jest bardzo złożone i wymaga wykonania symulacji pomocniczych...
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Sawing frozen wood with narrow kerf saws: Energy and quality effects.
PublicationOpór skrawania zależy podczas przecinania nie tylko od wilgotności drewna lecz również od jego temperatury. W pracy przedstawiono wyniki badań eksperymentalnych przecinania drewna sosnowego zmrożonego na pilarce ramowej wielopiłowej. Dla porównania wykonano również testy dla drewna o temperaturze pokojowej. Czynnikami badanymi były: moc skrawania, dokładność przecinania w postaci grubości elementów, a także chropowatość powierzchni....
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Experimental Investigations On The Momentum Pressure Drop During Flow Boiling Of R134a
PublicationThe article presents experimental investigations of the pressure drop during twophase flow. Experiments were performed for both adiabatic and heated flow of R134a. Obtained flow patterns were compared with the literature. Obtained data is used to validate momentum pressure drop predictions, a set of graphs showing comparisons, for a representative set of experimental conditions, of the two-phase frictional pressure gradients for...
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Experimental examination and modification of chip suction system in circular sawing machine
PublicationThe article presents the results of experimental examination of the wood chip suction system in the existing sliding table saw before and after its modifi cation. The studies focused on the extraction hood of the mentioned system. The methodical experimental research of the pressure distribution inside the hood during wood chip removal for the selected rotational speed of saw blades of 3500 and 6000 min-1 with a diameter of 300...
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An Experimental Investigation of Pressure Wave Celerity During the Transient Slurry Flow
PublicationTransportation of slurries in pressure pipelines is an example of a complex flow due to specific parameters of transported medium. For practitioners, the economy of designing and maintenance is usually the most important factor. For this reason, most of hydrotransport installations are fairly simple; however, they become more vulnerable to negative effects of the transient flow which can occur in pressure pipelines. As the consequence,...
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Relationships between Trust and Collaborative Culture in The Context of Tacit Knowledge Sharing
PublicationThe literature review presents a lot of theoretical and empirical evidence that Trust affects Collaborative Culture. The opposite also proves to be true: Collaborative Culture influences Trust. The main hypothesis presented in this paper says that both these factors are strongly correlated and modify each other. This study examines the mutual relationship of the said variables in the context of Tacit Knowledge Sharing based on...
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Simulations of air and water flow in a model dike during overflow experiments
PublicationFlow in flood dikes, earth dams, and embankments occurs in variably saturated conditions, with pores of the earth material filled partly with water and partly with air. In routine engineering analysis, the influence of pore air is neglected and the air pressure is assumed equal to atmospheric. In some circumstances, for example, during overtopping of the dike by water, the effect of pore air on water flow and stability of the structure...
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Advantages of the Application of the Temper Bead Welding Technique During Wet Welding
PublicationThermo-mechanically rolled S460ML steel was chosen for welding in underwater wet welding conditions by covered electrodes. The main aim of this study was to check the weldability for fillet welds in a water environment by controlled thermal severity (CTS) tests and to check the influence of temper bead welding (TBW) on the weldability of the investigated steel. Non-destructive and destructive tests showed that S460ML steel has...
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Sizes of iron hydroxide particles formed during ferric coagulation processes
PublicationThe aim of the study was to apply laser granulometer for measuring sizes of particles formed in iron-based coagulation process in water, which did not contain significant amounts of organic compounds. The research was conducted using tap water, obtained from underground sources. Iron sulfate in doses of 2.0–10.0 mgFe L–1 was added to water. During initial stage of flocculation, iron hydroxide particles reached dimensions between...
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Curing epoxy with electrochemically synthesized Zn Fe3-O4 magnetic nanoparticles
PublicationCathodic electrodeposition (CED) was applied in synthesis of undoped and zinc (Zn) doped Fe3O4 nanoparticles. Changes in the lattice structure of nanoparticles were monitored using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) supported by dispersive X-ray spectrometry (EDS), and vibrating sample magnetometry (VSM). Detailed analyses explored the formation of ZnxFe3–xO4 nanoparticles with x ≈ 0.1,...
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IMPACT OF THE ORGANISATION OF MEGA SPORTING EVENTS ON SELECTED ELEMENTS OF THE TOURISM SECTOR
PublicationIntroduction. In the world-wide literature, there is no unanimity in the assessment of the impact of mega sporting events on the tourism sector. Therefore, the main purpose of this study was to quantify the impact of mega sporting events on changes in tourist inflow and the amount of expenditure incurred by visitors. Material and methods. In this study, an ex-post analysis of many different categories of mega sporting events was...
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Analyses of static displacements of a spindle apllied in typical circular sawing machines
PublicationW pracy przedstawiono analizę właściwości statycznych wrzeciona stosowanego w typowych pilarkach tarczowych. Zdefiniowano umowną oś obrotu wrzeciona pilarki tarczowej, która odpowiada geometrycznemu środkowi otworu piły tarczowej. W obliczeniach wyznaczono przemieszczenia umownej osi obrotu wrzeciona, wskaźnik sztywności wrzeciona oraz przemieszczenie poprzeczne piły.
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Assessment of reformer tubes degradation during longterm service at elevated temperatures
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Abrasive property evaluation during microgrinding with single-disk lapping kinematics
PublicationPrzedstawiono wyniki badań mikroszliwowania z kinematyką docierania jednotarczowego. Analizowano narzędzie pod kątem trwałości. Wyznaczono zmieniające się właściwości ścierne narzędzia z wykorzystaniem systemu do automatycznej analizy obrazu.
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Adjusted SpikeProp algorithm for recurrent spiking neural networks with LIF neurons
PublicationA problem related to the development of a supervised learning method for recurrent spiking neural networks is addressed in the paper. The widely used Leaky-Integrate-and-Fire model has been adopted as a spike neuron model. The proposed method is based on a known SpikeProp algorithm. In detail, the developed method enables gradient descent learning of recurrent or multi-layer feedforward spiking neural networks. The research included...
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Intercomparison on measurements of PCBs in pork fat during the Belgian PCB-crisis
PublicationW pracy przedstawiono wyniki porównania międzylaboratoryjnego oznaczania PCB w tłuszczu wieprzowym. Porównanie międzylaboratoryjne przeprowadzono w związku z tzw. "belgijskim kryzysem PCB" w latach 1999-2000. W porównaniu uczestniczyło 31 laboratoriów. Materiałem do badań były wyprodukowane w Instytucie Metod i Pomiarów Odniesienia (IRMM) w Geel - Belgia, trzy materiały odniesienia zawierające PCB w tłuszczu wieprzowym (suma PCB...
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Pounding of structures during earthquakes modelled by nonlinear viscoelastic impact element.
PublicationAnalizowano zderzenia konstrukcji budowlanych podczas trzęsień ziemi wykorzystując model lepkosprężysty siły zderzenia. W analizie, zachowanie konstrukcji o różnych własnościach dynamicznych symulowane jest modelem dyskretnym o skupionych masach. wyniki badań pokazują, iż zderzenie może prowadzić do znacznego wzrostu odpowiedzi konstrukcji mniej sztywnej i lżejszej.
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Harmonic Synthesis: A Novel Electrochemical Method for Corrosion Rate Moni-toring
PublicationPraca przedstawia metodę wyznaczania chwilowej szybkości korozji metali opa-rtą na pomiarach prądów harmonicznych elektrody pobudzanej sinusoidalnym sy-gnałem napięciowym o niskiej częstotliwości i amplitudzie rzędu 10-30 mV,zapewniającej nieniszczący charakter badań. Opisano podstawy teoretyczne tejmetody nazwanej syntezą harmoniczną (SH). Jest ona oparta na dyskretnej syn-tezie quasi-stacjonarnej krzywej polaryzacji z prądów...
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Failure of austenitic stainless steel tubes during steam generator operation
PublicationThe article presents the failure process of austenitic stainless steels used in power devices, such as heat exchangers, steam generators, in terms of local corrosion: pitting, stress and intergranular corrosion, paying particular attention to welded joints area. The effect of steel chemical composition, microstructure, welding process and work environment was analyzed. The second part of the article presents the results of the...
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Granulometric characterization of Arctic driftwood sawdust from frame sawing process
PublicationArctic driftwood can be used as an alternative source of wood as construction timber and furniture material, especially in Iceland and Greenland. The use of Arctic driftwood can help in the fight against climate change, by developing land reforestation processes and reducing the volume harvested wood from forests and sustainability of harvesting processes. In this paper the results of an analysis of the effect of long-term residence...
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Experimental and Numerical Investigations of the Effect of Curing Conditions on the Temperature Rise of Concrete
PublicationThis paper presents experimental and numerical studies investigating the impact of three curing conditions on temperature evolution in concrete cubes. The tests were performed on samples of the same volume (3.375 dm3) under different curing conditions: room temperature, insulation boxes, and adiabatic calorimeter. Various cements (Portland cement, Portland composite cement, and blast furnace slag cement) and aggregates (gravel...
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Multibaem Sonar Records Data Decimation Using Hierarchical Spline Interpolation
PublicationMultibeam sonar records feature high vertical and horizontal resolution. Interpolating and approximating, eventually displaying of of high volume scattered 3D raster data leads to some difficulties related to a computer processing power. The paper presents some advantages of using hierarchical splines in the context. Such an approach facilitates real time 3D MBS data rendering.
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Pressure drop and heat transfer during boiling and condensation at subcritical region
PublicationMost of the data presented in the literature relate to saturation temperatures in the range - 20°C to 40°C due to the application in refrigeration technology. There is necessity to extend databases to higher values of saturation temperature due to new applications such as Organic Rankine Cycle and high temperature heat pumps. Only few papers contain data for high reduced pressure for low boiling point liquids. This paper focus...
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Influence of Actual Curing Conditions on Mechanical Properties of Concrete in Bridge Superstructures
PublicationThis article presents the research on the mechanical characteristics of concrete in the construction of three concrete bridges. A system of recording the internal temperature of concrete and automatic control of laboratory ovens was used for specimen curing. This allowed the specimens to be cured under conditions similar to those occurring in the structure. Before the construction, reference blocks were used to define similar curing...
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Understanding Fuel Saving and Clean Fuel Strategies Towards Green Maritime
PublicationDue to recent emission-associated regulations imposed on marine fuel, ship owners have been forced to seek alternate fuels, in order to meet the new limits. The aim of achieving low-carbon shipping by the year 2050, has meant that alternative marine fuels, as well as various technological and operational initiatives, need to be taken into account. This article evaluates and examines recent clean fuels and novel clean technologies...
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Predicting the peak structural displacement preventing pounding of buildings during earthquakes
PublicationThe aim of the present paper is to verify the effectiveness of the artificial neural network (ANN) in predicting the peak lateral displacement of multi-story building during earthquakes, based on the peak ground acceleration (PGA) and building parameters. For the purpose of the study, the lumped-mass multi-degree-of-freedom structural model and different earthquake records have been considered. Firstly, values of stories mass and...
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Lateral forces determine dimensional accuracy of the narrow‑kerf sawing of wood
PublicationThe shrinking global forest area limits the supply of industrially usable raw resources. This, in combination with the ever‑increasing consumption of timber due to population growth can lead to the lack of a positive balance between the annual volumetric growth and consumption of wood. An important innovation toward increasing environmental and economic sustainability of timber production is to reduce the volume of wood residues...
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Smart platforms for collaborative urban design and peer-to-peer sharing of resources
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Boundary effects on behaviour of granular material during plane strain compression
PublicationW artykule przedstawiono wyniki symulacji lokalizacji odkształceń w materiałach granulowanych podzcas sciskania dwuosiowego. Obliczenia wykonano przy zastosowaniu metody elementów skończonych i mikropolarnego modelu hipoplastycznego. W pracy pokazano wpływ warunków brzegowych na globalne i loklane zachowanie sie materiału.
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Investigations of size effects in granular bodies during plane strain compression
PublicationArtykuł omawia deterministyczny i statystyczny efekt skali w materiałach granulowanych podczas ściskania w płaskim stanie odkształcenia. Obliczenia wykonano metodą elementów skończonych na bazie mikropolarnego prawa hipoplastycznego. Wykorzystano metodę hiperłacińskiego próbkowania w celu redukcji ilości realizacji.
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Effect of heterogeneity on shear zone formation during plane strain compression.
PublicationW artykule przedstawiono wyniki numerycznej analizy ściskania w płaskim stanie odkształcenia dla materiałów granulowanych. Obliczenia przeprowdzono z modelem hipoplastycznym rozszerzonym o obroty i długość charakterystyczną. Obliczenia wykonno dla różnych rodzajów imperfekcji w próbce piasku zagęszczonego i luźnego.
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Experimental and theoretical studies on resonance dynamic effects during silo flow.
PublicationPrzedstawiono badania nad rezonansowymi efektami dynamicznymi podczas przepływów silosowych. Wpływ rezonansu na wielkość naporu był analizowany przy pomocy badań doświadczalnych i obliczeń MES na bazie prawa mikropolarnego sprężysto-plastycznego. Zaproponowano efektywną metodę redukcji efektów dynamicznych.