Filters
total: 2965
filtered: 1957
-
Catalog
- Publications 1957 available results
- Journals 106 available results
- Conferences 1 available results
- Publishing Houses 1 available results
- People 46 available results
- Projects 13 available results
- e-Learning Courses 531 available results
- Events 12 available results
- Open Research Data 298 available results
Chosen catalog filters
displaying 1000 best results Help
Search results for: ELASTO-PLASTICITY
-
Protokoły łączności do transmisji strumieni multimedialnych na platformie KASKADA
PublicationPlatforma KASKADA rozumiana jako system przetwarzania strumieni multimedialnych dostarcza szeregu usług wspomagających zapewnienie bezpieczeństwa publicznego oraz ocenę badań medycznych. Wydajność platformy KASKADA w znaczącym stopniu uzależniona jest od efektywności metod komunikacji, w tym wymiany danych multimedialnych, które stanowią podstawę przetwarzania. Celem prowadzonych prac było zaprojektowanie podsystemu komunikacji...
-
Complementary study with magnetic and acoustic techniques of A336 steel damage state due to creep
PublicationBadano możliwość detekcji w sposób nieniszczący zmian w mikrostrukturze stali A336 poddanej próbie pełzania. Testowano dwie magnetyczne techniki (klasyczny efekt Barkhausena i emisję magnetoakustyczną) oraz dwie nowe techniki ultradźwiękowe (pomiar współczynnika elasto-akustycznego oraz dwójłomność akustyczną). Wykazano, iż wyniki badań akustycznych są komplementarne do wyników badań magnetycznych.
-
A continual model of a damaged medium used for analyzing fatigue life of polycrystalline structural alloys under thermal–mechanical loading
PublicationThe main physical laws of thermal–plastic deformation and fatigue damage accumulation processes in polycrystalline structural alloys under various regimes of cyclic thermal–mechanical loading are considered. Within the framework of mechanics of damaged media, a mathematical model is developed that describes thermal–plastic deformation and fatigue damage accumulation processes under low-cycle loading. The model consists of three...
-
Physical and Mechanical Evaluation of Silicone-Based Double-Layer Adhesive Patch Intended for Keloids and Scar Treatment Therapy
PublicationGrowing interest in silicone elastomers for pharmaceutical purposes is due to both theirbeneficial material effect for scar treatment and their potential as drug carriers. Regarding their morphological structure, silicone polymers possess unique properties, which enable a wide range of applicability possibilities. The present study focused on developing a double-layer adhesive silicone film (DLASil) by evaluating its physical...
-
Cavitation erosion degradation of Belzona® coatings
PublicationIn hydrocarbon and maritime industry there is a constant need of materials and coatings withstanding severe conditions. One of adverse phenomena present there is cavitation erosion. The paper presents evaluation of cavitation resistance of three different steel coatings. Belzona 2141 (ACR-Fluid Elastormer), 1321 (Ceramic S-Steal) and 5831 (ST-Barrier) were deployed on P110 steel and subjected to ultrasound cavitation in distilled...
-
Improvement of Performance Level of Steel Moment-Resisting Frames Using Tuned Mass Damper System
PublicationIn this paper, parameters of the tuned mass dampers are optimized to improve the performance level of steel structures during earthquakes. In this regard, a six-story steel frame is modeled using a concentrated plasticity method. Then, the optimum parameters of the Tuned Mass Damper (TMD) are determined by minimizing the maximum drift ratio of the stories. The performance level of the structure is also forced to be located in a...
-
Finite element modelling of a historic church structure in the context of a masonry damage analysis
PublicationThe paper includes a case study of modelling a real historic church using the finite element method (FEM) based on laser scans of its geometry. The main goal of the study was the analysis of the causes of cracking and crushing of masonry walls. An FEM model of the structure has been defined in ABAQUS. A non-linear dynamic explicit analysis with material model including damage plasticity has been performed. A homogenization procedure...
-
Effect of microstructure on mechanical properties and corrosion resistance of 2205 duplex stainless steel
PublicationThis paper presents results of the research on impact of microstructure of austenitic-ferritic steel of duplex type on its mechanical properties and susceptibility to stress corrosion cracking. As showed, improper processing technologies more and more often used in shipbuilding industry for plates and other half-finished products made of duplex steel may cause significant lowering their properties, which frequently makes their...
-
Local properties of organic coatings close to glass transition temperature
PublicationAcrylic coating applied on copper substrate has been investigated at different temperatures starting from the ambient one up to the level above the glass transition temperature. Its local topographic and electric properties have been examined with the atomic force microscopy (AFM) based approach including dc current mapping and local impedance spectroscopy. The local findings have been compared with the information from global...
-
Damage Analysis of Tensioning Cable Anchorage Zone of a Bridge Superstructure, Using CDP Abaqus Material Model
PublicationNumerical analysis of the tensioning cables anchorage zone of a bridge superstructure is presented in this paper. It aims to identify why severe concrete cracking occurs during the tensioning process in the vicinity of anchor heads. In order to simulate the tensioning, among others, a so-called local numerical model of a section of the bridge superstructure was created in the Abaqus Finite Element Method (FEM) environment. The...
-
Preliminary study of linear viscoelasticity limits of cold recycled mixtures determined in Simple Performance Tester (SPT)
PublicationThe publication presents methodology developed for determination of linear viscoelasticity limits for cold recycled mixtures with cement and bituminous emulsion using Simple Performance Tester (SPT). Methodology was verified on reference materials (PCV and steel dummy specimens, cement concrete and asphalt concrete) to comply with elasticity and viscoelasticity theory. The developed methodology enabled determination of linear viscoelasticity...
-
Ocena akustycznego zagrożenia środowiska w związku z imprezą „Celtyckie lato w Gdyni” odbywającą się w muszli koncertowej na placu Grunwaldzkim w Gdyni w dniu 28.08.2016
Publication.
-
HYGRO-MAGNETIC VIBRATION OF THE SINGLE-WALLED CARBON NANOTUBE WITH NONLINEAR TEMPERATURE DISTRIBUTION BASED ON A MODIFIED BEAM THEORY AND NONLOCAL STRAIN GRADIENT MODEL
PublicationIn this study, vibration analysis of single-walled carbon nanotube (SWCNT) has been carried out by using a refined beam theory, namely one variable shear deformation beam theory. This approach has one variable lesser than a contractual shear deformation theory such as first-order shear deformation theory (FSDT) and acts like classical beam approach but with considering shear deformations. The SWCNT has been placed in an axial or...
-
Equalization of pad loads in large tilting pad thtust bearing
PublicationW pracy przedstawiono przebieg projektowania zmodernizowanego łożyska wzdłużnego hydrogeneratora. Na podstawie eksploatacyjnych danych o zróżnicowaniu temperatury klocków łożyskowych, na drodze obliczeń elasto-termo-hydrodynamicznych, stwierdzono konieczność wyrównania rozkładu obciążenia na poszczególne klocki łożyska. Cel został osiągnięty poprzez wprowadzenie podatnego podparcia segmentów łożyska na sprężynach płytowych, których...
-
On a flexomagnetic behavior of composite structures
PublicationThe popularity of the studies is getting further on the flexomagnetic (FM) response of nano-electro-magneto machines. In spite of this, there are a few incompatibilities with the available FM model. This study indicates that the accessible FM model is inappropriate when considering the converse magnetization effect that demonstrates the necessity and importance of deriving a new FM relation. Additionally, the literature has neglected...
-
On the influence of a surface roughness on propagation of anti-plane short-length localized waves in a medium with surface coating
PublicationWe discuss the propagation of localized surface waves in the framework of the linear Gurtin–Murdoch surface elasticity and taking into account a roughness of a free boundary. We derive a boundary-value problem for anti-plane motions with curvilinear boundary and surface stresses. Using the asymptotic technique developed earlier, we obtain the form of a localized wave and analyze its amplitude evolution. As the main result we present...
-
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...
-
Effective Friction Angle Of Deltaic Soils In The Vistula Marshlands
PublicationThis article presents the results of laboratory tests on soft, normally consolidated soils from the Vistula Marshlands. Samples of high-plasticity organic soils (muds) taken from 3.2–4.0 m and 9.5–10.0 m depth, as well as peat deposit at 14.0 m, are analysed. Presented case study confirms the applicability of the Norwegian Institute of Technology (NTH) method based on Cone Penetration Tests (CPTU) and allows for a conservative...
-
Estimation of fracture toughness and shear yield stress of orthotropic materials in cutting with rotating tools
PublicationThe cutting force is an energetic effect of splitting material, and might be considered from a point of view of modern fracture mechanics. Forecasting of the shear plane angle in cutting broaden possibilities for modelling of the cutting process even for thin uncut chips. Such mathematical model has been developed here for description of the orthotropic materials’ cutting on the base of fracture theory, and includes work of separation...
-
Projektowanie budynków użyteczności publicznej narażonych na ataki terrorystyczne z wykorzystaniem systemu ochrony pasywnej
PublicationW artykule przedstawiono projektowanie systemów ochrony pasywnej w budynkach użyteczności publicznej, które mogą posłużyć jako przykład i stanowić podstawę do dalszych założeń przy projektowaniu budynków narażonych na obciążenie wybuchem spowodowanym przez ataki terrorystyczne. W pracy przeprowadzono symulacje numeryczne na przykładzie ściany budynku użyteczności publicznej wykonanego w technologii żelbetowej. Obliczenia wykonano...
-
Effect of adhesive compliance in the assessment of soft adhesives with the wedge test
PublicationWedge tests are usually analysed assuming that the free, unbonded members may be treated as encastré cantilever beams. However, if the adhesive layer is sufficiently flexible (e.g., due to low elastic modulus), then significant strain in the bonded region may occur and lead to modification of the behaviour outside this region. Using in conjunction a sensitive strain gauge method on asymmetric wedge tests and a mathematical analysis...
-
Central-force decomposition of spline-based modified embedded atom method potential
PublicationCentral-force decompositions are fundamental to the calculation of stress fields in atomic systems by means of Hardy stress. We derive expressions for a central-force decomposition of the spline-based modified embedded atom method (s-MEAM) potential. The expressions are subsequently simplified to a form that can be readily used in molecular-dynamics simulations, enabling the calculation of the spatial distribution of stress in...
-
Wulkanizaty kauczuku naturalnego otrzymane z użyciem plastyfikatorów pochodzenia roślinnego
PublicationCelem niniejszej pracy było zbadanie wpływu epoksydowanych olejów roślinnych na wybrane właściwości wul-kanizatów kauczuku naturalnego. Jako plastyfikatorów użyto epoksydowanego oleju sojowego oraz epoksydo-wanego oleju palmowego. Wpływ olejów naturalnych porównano także z wulkanizatami przygotowanymi bez użycia zmiękczaczy, jak i zawierającymi olej maszynowy, pochodzący z przerobu ropy naftowej. Zbadano wpływ rodzaju...
-
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...
-
Distorsional analysis of I-section beam
PublicationAn elastic stiffness matrix was derived in the case of distortion of a restrained thin-walled I-section beam using the minimum total stationary elastic energy condition. The function describing the angle of distortion was adopted form the solution of differential equation in the case of restrained distortion. The example presented in the paper helps to assess the correctness of the proposed solution. The proposed elastic stiffness...
-
Design and evaluation of a base module of active power electronic transformer
Publication -
Design and evaluation of a base module of active power electronic transformer
PublicationThis paper presents an active power electronic transformer (APET) based on modular structure. The proposed three phase APET consists of at least three base modules (BM). The input/output stage of the BM is based on half-bridge sub modules. The isolation stage includes a medium frequency transformer and is realized as a dual half-bridge. The paper describes construction process and explains the control strategy. The theoretical...
-
Analytical comparison between capacitor assisted and diode assisted cascaded quasi-z-source inverters
PublicationQuasi-Z falownik z prostym obwodem impedancyjnym jest bardzo interesującym rozwiązaniem topologicznym ze względu na unikalną możliwość jednostopniowego przekształcanie DC/AC w połączeniu z funkcjami obniżania i podwyższania napięcia. W niektórych aplikacjach jego właściwości podwyższające są jednak niewystarczające. Wyższe napięcie wejściowe można uzyskać w wyniku zastosowania w quasi-Z-falownikach kaskadowych obwodów impedancyjnych....
-
On forced vibrations of piezo-flexomagnetic nano-actuator beams
PublicationThe effect of excitation frequency on the piezomagnetic Euler-Bernoulli nanobeam taking the flexomagnetic material phenomenon into consideration is investigated in this chapter. The magnetization with strain gradients creates flexomagneticity. We couple simultaneously the piezomagnetic and flexomagnetic properties in an inverse magnetization. Resemble the flexoelectricity, the flexomagneticity is also size-dependent. So, it has...
-
BLOOD PRESSURE ESTIMATION BY MEANS OF A JOINT IMPEDANCE– PHOTOPLETYSMOGRAPHIC METHOD
PublicationThe knowledge of patient’s day to day blood pressure changes is invaluable to physicians for both diagnostics and health monitoring reasons. Constant observation of the pressure throughout a day would provide even more valuable clinical information. A convenient non-invasive methods of blood pressure estimation for monitoring purposes are widely proposed. This work shows a statistical approach to...
-
Buckling Analysis of a Micro Composite Plate with Nano Coating Based on the Modified Couple Stress Theory
PublicationThe present study investigates the buckling of a thick sandwich plate under the biaxial non-uniform compression using the modified couple stress theory with various boundary conditions. For this purpose, the top and bottom faces are orthotropic graphene sheets and for the central core the isotropic soft materials are investigated. The simplified first order shear deformation theory (S-FSDT) is employed and the governing differential...
-
Hydrogen Damage in Superaustenitic 904L Stainless Steels
Publicationresults on the influence of hydrogen on corrosion resistance and of hydrogen embrittlement of 904L superaustenitic stainless steel were investigated. The cracking behavior was studied by performing a slow strain rate test in synthetic seawater under varying cathodic polarization conditions. The results showed that the steel’s plasticity varied with the applied cathodic current density. Significant reductions in ductility were found,...
-
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...
-
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 (or power - more interesting from energetic point of view) could be considered from a point of view of modern fracture mechanics. Cutting...
-
A constitutive law for concrete with smooth transition from continuous into discontinuous cracks’ description
PublicationPaper presents a constitutive model for concrete that combines a continuous and discontinuous crack’s description to simulate the concrete under tensile dominated loads. In a continuum regime, two different constitutive laws were used. First, a plasticity model with the Rankine failure criterion and an associated flow rule was used. Second, a constitutive law based on isotropic damage mechanics was formulated. Both model alternatives...
-
The Sustainable Development and Economic Impact of China’s Belt and Road Initiative in Ethiopia
Publication -
Reactivation of seizure‐related changes to interictal spike shape and synchrony during postseizure sleep in patients
PublicationOBJECTIVE: Local field potentials (LFPs) arise from synchronous activation of millions of neurons, producing seemingly consistent waveform shapes and relative synchrony across electrodes. Interictal spikes (IISs) are LFPs associated with epilepsy that are commonly used to guide surgical resection. Recently, changes in neuronal firing patterns observed in the minutes preceding seizure onset were found to be reactivated during postseizure...
-
Management of complexity and information flow
PublicationProblemy złożoności i zarządzania przepływem informacji. W rozdziale omówio-no podejście do modelowania systemów złożonych oraz zarządzania przepływeminformacji w takich systemach. Rozwiązania odniesiono do płaszczyzny elasty-cznego wytwarzania. Poruszono aspekty miękkiego modelowania w takich środo-wiskach.
-
Comparison of experimental and numerical results on metallic plates subjected to explosions
PublicationA comparative study of dynamic response including damage and rupture processes of thin metallic plates subjected to shockwave impulses - explosions is presented. The results of the finite element numerical analysis are related to experiments. Due to high strain rate during explosions the elasto-viscoplastic Chaboches constitutive law including damage effects has been applied. For the assumed model proper material parameters identification...
-
Statistical evaluation of physical and index properties of Vistula Marshlands deltaic soft soils
PublicationThis paper provides statistical evaluation of physical and index parameters of the Vistula Marshlands deltaic soft soils using three datasets. Soft soils from the Vistula Marshlands are grouped into the four categories: (1) silty/sandy loams, (2) organic clays, (3) organic silts and (4) peats. Variability of basic and derivative physical properties as well as Atterberg's limits and plasticity index is studied. It is found that...
-
AN ALTERNATIVE WAY OF DETERMINING MECHANICAL PROPERTIES OF WOOD BY MEASURING CUTTING FORCES
PublicationThe cutting force is an energetic effect of splitting material, and might be therefore considered from a point of view of modern fracture mechanics. The dedicated mathematical model developed for description of the wood cutting has been developed here on the base of fracture theory, and includes work of separation (fracture toughness) in addition to the material plasticity and friction. The effect of the cutting edge dullness is...
-
COMPARISON OF TWO MODELS OF CONDENSATION
PublicationIn the low-pressure part of steam turbine, the state path usually crosses the saturation line in penultimate stages. At least last two stages of this part of turbines operate in two –phase region. The liquid phase in this region in mainly created in the process of homogeneous and heterogeneous condensation. Several observations confirm however, that condensation often occurs earlier than it is predicted by theory i.e. before the...
-
Quality assessment of ZnO-based varistors by 1/f noise
PublicationNoise has been used as a diagnostic tool of surge arrester varistor structures comprising of ZnO grains of various type and size. The physical and electrical properties of the measured samples have been described. In the experimental study, the applied measurement system and the results of noise measurements for the selected structures of varistors designed for the continuous working voltage 280 V, 440 V and 660 V have been presented....
-
On instabilities and post-buckling of piezomagnetic and flexomagnetic nanostructures
PublicationWe focus on the mechanical strength of piezomagnetic beam-like nanosize sensors during post-buckling. An effective flexomagnetic property is also taken into account. The modelled sensor is selected to be a Euler-Bernoulli type beam. Long-range interactions between atoms result in a mathematical model based on the nonlocal strain gradient elasticity approach (NSGT). Due to possible large deformations within a post-buckling phenomenon,...
-
Synthesis, Structure and Properties of Poly(ester-Urethane-Urea)s Synthesized Using Biobased Diamine
PublicationModern polymer science and technology is focused on the development of partial or fully green polymers. This focus is related to green chemistry trends, which propose using natural and renewable resources as monomers in the synthesis of polymers. In this study, biobased diamine was used as a chain extender of ester-urethane prepolymer. Obtained poly(ester-urethane-urea) contains 16 wt% of biobased diamine. There is mention of an...
-
Numerical modelling of 3D printout using line (1D) elements
PublicationA proposition of some numerical modelling of the 3D printout is presented in the paper. The proposed model is composed of some 1D elements. The resulting numerical model of the infill consist of beam, spring and rigid elements. Obtained results confirm correctness of the proposed modelling method. Two methods of estimation of the spring parameters are proposed in the paper. In the first method, mechanical properties of the connecting...
-
Influence of steam drying process on wood mechanical properties
PublicationResults of influence of gas-steam mixture drying process on mechanical properties of material are presented. Wood species, namely oak (Quercus L.), beech (Fagus L.), pine (Pinus L.) and spruce (Picea K.) from the northern part of Pomerania region in Poland, were subject of air-steam mixture drying process in a laboratory kiln especially arranged for that reason. Measurements of the global coefficient of elasticity and bending strength...
-
Wave transmission across surface interfaces in lattice structures
PublicationWithin the lattice dynamics formulation, we present an exact solution for anti-plane surface waves in a square lattice strip with a surface row of material particles of two types separated by a linear interface. The considered problem is a discrete analog of an elastic half-space with surface stresses modelled through the simplified Gurtin–Murdoch model, where we have an interfacial line separating areas with different surface...
-
Religious social action and its organizational profiles
PublicationPurpose Social action implemented by the Church via its affiliated entities, foundations and associations may be viewed as a uniform activity. In reality, however, several organizational profiles exist that depend on the origin of these organizations (lay or religious), the scope of their activities (local or general) and their dependence on resources (whether from public administration or civil society). The paper aims to discuss...
-
On the effective properties of foams in the framework of the couple stress theory
PublicationIn the framework of the couple stress theory, we discuss the effective elastic properties of a metal open-cell foam. In this theory, we have the couple stress tensor, but the microrotations are fully described by displacements. To this end, we performed calculations for a representative volume element which give the matrices of elastic moduli relating stress and stress tensors with strain and microcurvature tensors.