Wyszukiwarka
Filtry
wszystkich: 1136
wybranych: 1058
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: spectral finite element method
-
Biomechanics of Lumbar Spine Injury in Road Barrier Collision–Finite Element Study
PublikacjaLiterature and field data from CIREN database have shown that lumbar spine injuries occur during car crashes. There are multiple hypotheses regarding how they occur; however, there is no biomechanical explanation for these injuries during collisions with road safety barriers (RSBs). Therefore, the objective of this study was to investigate the mechanics of vertebral fractures during car collisions with concrete RSBs. The finite...
-
Review of constitutive models for technical woven fabrics in finite element analysis
PublikacjaArtykuł opisuje typy modeli konstytutywnych stosowanych do opisu zachowania się tkanin technicznych w analizie MES. Proponowany jest także warstwowy model sieci gęstej.
-
Geometrically nonlinear finite element simulation of smart piezolaminated plates and shells
PublikacjaW pracy zaproponowano powłokowy element skończony pozwalający na uwzględnienie efektu piezoelektrycznego. Element został wykorzystany w podejściu Lagrange'a, które wymaga starannego dobrania definicji wielkości mechanicznych i elektrycznych. Zależności przemieszczenie-odkształcenie zbudowano na bazie teorii małych odkształceń i umiarkowanych obrotów. Założono liniowy rozkład pól odkształceń i pola elektrycznego po grubości powłoki....
-
Comment on permeability conditions in finite element simulation of bone fracture healing
PublikacjaThe most popular model of the bone healing considers the fracture callus as poroelastic medium. As such it requires an assumption of the callus’ external permeability. In this work a systematic study of the influence of the permeability of the callus boundary on the simulated bone healing progress is performed. The results show, that these conditions starts to play significant role with the decrease of the callus size. Typically...
-
Finite element modeling of shear localization in granular bodies in hypoplasticity with enhancements
PublikacjaW pracy omówiono wyniki numeryczne lokalizacji okształceń stycznych w materiałach granulowanych. Obliczenia wykonano stosując prawo hipoplastyczne z rozszerzeniami w ramach mechaniki ośrodka gradientowego, nielokalnego i mikropolarnego. Obliczenia przeprowadzono dla różnych problemów brzegowych z uwzględnieniem lokalizacji. Wyniki analiz porównano z doświadczeniami.
-
Communication and Load Balancing Optimization for Finite Element Electromagnetic Simulations Using Multi-GPU Workstation
PublikacjaThis paper considers a method for accelerating finite-element simulations of electromagnetic problems on a workstation using graphics processing units (GPUs). The focus is on finite-element formulations using higher order elements and tetrahedral meshes that lead to sparse matrices too large to be dealt with on a typical workstation using direct methods. We discuss the problem of rapid matrix generation and assembly, as well as...
-
Structural properties of foil bearings: a closed-form solution validated with finite element analysis
PublikacjaFluid film thickness in a compliant foil bearing is greatly influenced by the deflection of the bearing structure. Therefore, in order to properly model performance of a foil bearing, it is mandatory that the deflection of the compliant bearing structure due to the generated hydrodynamic pressure is determined accurately. This article proposes an easy-to-use two-dimensional model, which takes into account detailed geometry of the...
-
Finite element/mode-matching analysis of ferrite/dielectric line junctions of arbitrary cross-section
PublikacjaThis paper is focused on the analysis of line junctions obtained as a cascade of dielectric and ferrite guides of arbitrary cross-section. The main application of such structures is nonreciprocal devices such as isolators, circulators, or phase shifters. The efficient finite element/mode-matching approach is proposed to the analysis of such structures. In this approach, thefiniteelementmethod is applied todetermine propagation...
-
Impact of the Finite Element Mesh Structure on the Solution Accuracy of a Two-Dimensional Kinematic Wave Equation
PublikacjaThe paper presents the influence of the finite element mesh structure on the accuracy of the numerical solution of a two-dimensional linear kinematic wave equation. This equation was solved using a two-level scheme for time integration and a modified finite element method with triangular elements for space discretization. The accuracy analysis of the applied scheme was performed using a modified equation method for three different...
-
Experimental Study and Finite Element Modeling of Reinforced Concrete Column Having an Opening
Publikacja -
Membrane shell finite element for textile fabric modelling numerical and experimental aspects
PublikacjaW pracy omówiono podstawowe problem numeryczne pojawiające się przy projektowaniu przekryć z tkanin technicznych. Przedstawiono eksperymenty potrzebne do identyfikacji właściwości mechanicznych takich tkanin.
-
Application of elasto-viscoplastic Bodner-Partom constitutive equations in finite element analysis
PublikacjaW artykule omówiono szczegółowo zastosowanie sprężysto-lepkoplastycznego prawa Bodnera-Partoma w analizie MES. Przedstawiono opis podstawowych równań modelu wraz z kodem procedury UVSCPL wykorzystanej w analizie numerycznej MES.
-
Comparison of modal and finite-element methods in the vibrational analysis of marine propulsion systems
PublikacjaW okrętowych układach napędowych występują dwa typy części składowych. Pierwszym z nich są odcinki wałów, które należą do elementów o ciągłym rozkładzie własności masowych, sprężystych i tłumiących oraz elementy o parametrach skupionych, do których można zaliczyć śrubę napędową, tarcze sprzęgieł i inne. W pracy porównano dwie metody modelowania takich układów. Pierwsza z nich związana jest z tworzeniem modeli przybliżonych w oparciu...
-
Step on It Bringing Fullwave Finite-Element Microwave Filter Design up to Speed
PublikacjaThere are many steps in the design of a microwave filter: mathematically describing the filter characteristics, representing the circuit as a network of lumped elements or as a coupling matrix, implementing the distributed elements, finding the initial dimensions of the physical structure, and carrying out numerical tuning using electromagnetic (EM) simulators. The whole process is painstaking and time-consuming, and it requires...
-
Formulation of spectral truss element for guided waves damage detection in spatial steel trusses
PublikacjaW pracy przedstawiono sformułowanie wielowęzłowego elementu spektralnego oraz odpowiedniego schematu całkowania ukierunkowanego na problem propagacji fal w kratownicach przestrzennych o dowolnej geometrii. Zaproponowane podejście nie ogranicza liczby węzłów w elemencie kratowym. Porównawcze rozwiązania numeryczne przeprowadzono dla konstrukcji idealnej (w stanie nieuszkodzonym) oraz dlakonstrukcji z miejscową nieregularnością w...
-
Determinants of the primary stability of cementless acetabular cup implants: A 3D finite element study
PublikacjaPrimary stability of cementless implants is crucial for the surgical success and long–term stability. However, primary stability is difficult to quantify in vivo and the biomechanical phenomena occurring during the press–fit insertion of an acetabular cup (AC) implant are still poorly understood. The aim of this study is to investigate the influence of the cortical and trabecular bone Young's moduli Ec and Et, the interference...
-
GPU-Accelerated Finite-Element Matrix Generation for Lossless, Lossy, and Tensor Media [EM Programmer's Notebook]
PublikacjaThis paper presents an optimization approach for limiting memory requirements and enhancing the performance of GPU-accelerated finite-element matrix generation applied in the implementation of the higher-order finite-element method (FEM). It emphasizes the details of the implementation of the matrix-generation algorithm for the simulation of electromagnetic wave propagation in lossless, lossy, and tensor media. Moreover, the impact...
-
Modeling by finite element methods of impact of erosion on frequency of normal modes of L-0 blade
PublikacjaAfter some time of exploitation steam turbine rotors blades in energetic industry they are being eroded and also their frequency of normal modes is changed. Those changes can cause to unwanted shift of blades normal mode frequencies. It is necessary to find quick method of rating changes of frequency in connection of mass loss due erosion. The evaluation of this dependence was made by finite element modeling method using HyperWorks...
-
A general isogeometric finite element formulation for rotation‐free shells with in‐plane bending of embedded fibers
PublikacjaThis article presents a general, nonlinear isogeometric finite element formulation for rotation-free shells with embedded fibers that captures anisotropy in stretching, shearing, twisting, and bending - both in-plane and out-of-plane. These capabilities allow for the simulation of large sheets of heterogeneous and fibrous materials either with or without matrix, such as textiles, composites, and pantographic structures. The work...
-
An isogeometric finite element formulation for boundary and shell viscoelasticity based on a multiplicative surface deformation split
PublikacjaThis work presents a numerical formulation to model isotropic viscoelastic material behavior for membranes and thin shells. The surface and the shell theory are formulated within a curvilinear coordinate system,which allows the representation of general surfaces and deformations. The kinematics follow from Kirchhoff–Love theory and the discretization makes use of isogeometric shape functions. A multiplicative split of the surface...
-
Updating Finite Element Model of a Wind Turbine Blade Section Using Experimental Modal Analysis Results
PublikacjaThis paper presents selected results and aspects of themultidisciplinary and interdisciplinary research oriented for the experimental and numerical study of the structural dynamics of a bend-twist coupled full scale section of awind turbine blade structure.Themain goal of the conducted research is to validate finite elementmodel of themodified wind turbine blade section mounted in the flexible support structure accordingly to the...
-
Application of the finite element methods in long-term simulation of the multi-physics systems with large transient response differences
PublikacjaApplication of the Finite Element Method (FEM) and the Multibody Dynamics Method allows analyzing of complex physical systems. Complexity of the system could be related both to the geometry and the physical description of phenomenon. The metod is the excellent tool for analyzing statics or dynamics of the mechanical systems, and permits tracking of Multi Body System (MBS) transient response for the long-term simulations and application...
-
Detection of damages in a rivetted plate
PublikacjaThe paper presents the results of damage detection in a riveted aluminium plate. The detection method has been based on Lamb wave propagation. The plate has been analysed numerically and experimentally. Numerical calculations have been carried out by the use of the time-domain spectral finite element method, while for the experimental analysis laser scanning Doppler vibrometry (LSDV) has been utilised. The panel has been excited...
-
Nonlinear finite element modeling of vibration control of plane rod-type structural members with integrated piezoelectric patches
PublikacjaThis paper addresses modeling and finite element analysis of the transient large-amplitude vibration response of thin rod-type structures (e.g., plane curved beams, arches, ring shells) and its control by integrated piezoelectric layers. A geometrically nonlinear finite beam element for the analysis of piezolaminated structures is developed that is based on the Bernoulli hypothesis and the assumptions of small strains and finite...
-
Harmonic Vibrations of Nanosized Magnetoelectric Bodies with Coupled Surface and Interphase Effects: Mathematical Models and Finite Element Approaches
PublikacjaThe harmonic problems for piezomagnetoelectric nanosized bodies with taking into account the coupled damping and surface effects are considered on the base of the generalized Gurtin-Murdoch model. In the development of previous investigations, the coupled mechanical, electric and magnetic surface effects with surface inertial terms are introduced into the model. For a homogeneous model, the composite material is considered as homogeneous...
-
A new anisotropic bending model for nonlinear shells: Comparison with existing models and isogeometric finite element implementation
PublikacjaA new nonlinear hyperelastic bending model for shells formulated directly in surface form is presented, and compared to four existing prominent bending models. Through an essential set of elementary nonlinear bending test cases, the membrane and bending stresses of each model are examined analytically. Only the proposed bending model passes all the test cases, while the other bending models either fail or only pass the test cases for...
-
Finite-element analysis of a base-isolated multi-storey steel building under seismic motions
PublikacjaNumerical simulation of the seismic behaviour of a multi-storey steel building, both fixed-base and base-isolated, under the 1940 El Centro earthquake was performed in this paper. The analyzed 4-storey building was decoupled from the shaking ground with the Polymeric Bearings, which can be considered a proposal of a new seismic isolation system. It consists of rectangular-shaped blocks made of a specially prepared flexible polymeric...
-
2-D constitutive equations for orthotropic Cosserat type laminated shells in finite element analysis
PublikacjaWe propose 2-D Cosserat type orthotropic constitutive equations for laminated shells for the purpose of initial failure estimation in a laminate layer. We use nonlinear 6-parameter shell theory with asymmetric membrane strain measures and Cosserat kinematics as the framework. This theory is specially dedicated to the analysis of irregular shells, inter alia, with orthogonal intersections, since it takes into account the drilling...
-
Finite element study of patterns of shear zones in granular bodies during plane strain compression
PublikacjaW artykule przedstawiono obliczenia efektów skali na nośność fundamentu na piasku. Obliczenia wykonano przy pomocy mikropolarnego prawa hipoplastycznego. W obliczeniach wykorzystano stochastyczne rozkłady początkowego wskaźnika porowatości według rozkładu Gaussa.
-
A finite element analysis of thermal energy inclination based on ternary hybrid nanoparticles influenced by induced magnetic field
PublikacjaThe use of hybrid nanoparticles to improve thermal processes is a key method that has implications for a variety of interventions utilized in many sectors. This paper aimed to look into the impacts of ternary nanoparticles on hyperbolic tangent materials to establish their thermal characteristics. Flow describing equations have been explored in the presence of heat production, non-Fourier heat flux, and an induced magnetic field....
-
Parametrized Local Reduced-Order Models With Compressed Projection Basis for Fast Parameter-Dependent Finite-Element Analysis
PublikacjaThis paper proposes an automated parametric local model-order reduction scheme for the expedited design of microwave devices using the full-wave finite-element method (FEM). The approach proposed here results in parameterized reduced-order models (ROMs) that account for the geometry and material variation in the selected subregion of the structure. In each subregion, a parameter-dependent projection basis is generated by concatenating...
-
Finite element analysis on failure of reinforced concrete corner in sewage tank under opening bending moment
PublikacjaW artykule omówiono mechanizm uszkodzenia żelbetowego zbiornika ściekowego w narożniku ściany, który uległ uszkodzeniu podczas próby wypełnienia na skutek nadmiernych przemieszczeń poziomych ścian pod wpływem otwierającego momentu zginającego. Aby wyjaśnić przyczyny awarii, przeprowadzono kompleksowe obliczenia metodą elementów skończonych (MES) żelbetowego zbiornika w warunkach odkształcenia płaskiego. Beton zamodelowano za pomocą...
-
Galerkin Finite Element Process for Entropy Production and Thermal Evaluation of Third-Grade Fluid Flow: A Thermal Case Study
Publikacja: A fluid’s moving class improves its heat transmission capability, as well as its rigidity, owing to multivariate molecule suspension. In this way, nanofluids are superior to common fluids. In this study, we evaluated the features of ease and heat transfer. Furthermore, we investigated permeable media, heat source, variable heat conductivity, and warm irradiation results. A mathematical technique known as the Galerkin finite element...
-
AN OVERVIEW OF HEAT TRANSFER ENHANCEMENT BASED UPON NANOPARTICLES INFLUENCED BY INDUCED MAGNETIC FIELD WITH SLIP CONDITION VIA FINITE ELEMENT STRATEGY
PublikacjaThe mathematical model of heat generation and dissipation during thermal energy transmission employing nanoparticles in a Newtonian medium is investigated. Dimensionless boundary layer equations with correlations for titanium dioxide, copper oxide, and aluminium oxide are solved by the finite element method. Parameters are varied to analyze their impact on the flow fields. Various numerical experiments are performed consecutively...
-
A three-dimensional periodic beam for vibroacoustic isolation purposes
PublikacjaThis paper presents results of investigations on a three-dimensional (3-D) isotropic periodic beam. The beam can represent a vibroacoustic isolator of optimised dynamic characteristics in the case of its longitudinal, flexural and torsional behaviour. The optimisation process concerned both the widths as well as the positions of particular frequency band gaps that are present in the frequency spectrum of the beam. Since the dynamic...
-
Historic bridge modelling using laser scanning, ground penetrating radar and finite element methods in the context of structural dynamics
PublikacjaPraca dotyczy modelowania MES zabytkowej konstrukcji mostowej przy użyciu danych geometrycznych pochodzących ze skanowania laserowego oraz georadaru. Z uwagi na brak badań materiału budujcego most, przeprowadza się analize wrażliwości konstrukcji na zmiany modułu sprężystości granitu.
-
Finite element investigations of granular material behaviour during cyclic wall shearing under a constant normal stiffness condition
PublikacjaW artykule przedstawiono wyniki numnerycznej analizy zachowania sie materiałów granulowanych podczas cyklicznego ścinanai wzdłuz szorstkiej ściany z warunkiem stałej sztywności normalnej. Obliczenia wykonano przy zastosowaniu metody elementów skończonych i mikropolarnego nodelu hipopalstycznego. Obliczenia wykonano dla róznych sztywności, początkowych wskaźników porowatości i sredniej średnicy ziarna. Wyniki numeryczne porównano...
-
Electromagnetic Control and Dynamics of Generalized Burgers’ Nanoliquid Flow Containing Motile Microorganisms with Cattaneo–Christov Relations: Galerkin Finite Element Mechanism
PublikacjaIn our research work, we have developed a model describing the characteristics of the bio-convection and moving microorganisms in the flows of a magnetized generalized Burgers’ nanoliquid with Fourier’s and Fick’s laws in a stretchable sheet. Considerations have been made to Cattaneo–Christov mass and heat diffusion theory. According to the Cattaneo–Christov relation, the Buongiorno phenomenon for the motion of a nanoliquid in...
-
Portico Farmhouses of the Vistula Delta: Architecture, Current State and Finite Element Modelling of Timber Roof Truss under Material and Cross-section Uncertainty
PublikacjaThe article focuses on the oldest surviving I-type portico houses located in the Vistula Delta, which were built in the 17th and 18th centuries. The study describes the houses’ origins, structure, details of roof structures and technical condition, and it also includes numerical modelling of a roof truss and its mechanical analysis. Numerical models of the roof trusses are defined and analysed by means of the finite element method....
-
Rigid Finite Element Modeling for Identification of Vibrations in Elastic in Elastic Rod Driven by a DC-motor Suplied from a Thyristor Rectifier
PublikacjaRozdział dotyczy analizy numerycznej układu elektromechanicznego. Układ składa się z silnika zasilanego z jednopołówkowego prostownika tysystorowego i napędzanego tym silnikiem wirującego pręta. Celem obliczeń jest określenie postaci i wielkości drgań pręta, jeśli uwzględniamy jego elastyczność. Dyskretna struktura modelu to łańcuch wielomasowy ciał - sztywnych ciał połączonych bezmasowymi węzłami. Autorzy obliczyli zachowanie...
-
Nonlinear harmonic amplitudes in air coils above and below a metal plate as a function of tensile strength via finite element simulation.
PublikacjaOpisano wyniki obliczeń numerycznych (symulacja metodą MES) wpływu naprężeń na amplitudy nieliniowych harmonicznych napięcia indukowanego w cewkach powietrznych umieszczonych nad i pod płytą.
-
Galerkin finite element analysis of Darcy–Brinkman–Forchheimer natural convective flow in conical annular enclosure with discrete heat sources
Publikacja -
The effective elastic properties of human trabecular bone may be approximated using micro-finite element analyses of embedded volume elements.
PublikacjaBoundary conditions (BCs) and sample size affect the measured elastic properties of cancellous bone. Samples too small to be representative appear stiffer under kinematic uniform BCs (KUBCs) than under periodicity-compatible mixed uniform BCs (PMUBCs). To avoid those effects, we propose to determine the effective properties of trabecular bone using an embedded configuration. Cubic samples of various sizes (2.63, 5.29, 7.96, 10.58...
-
Maximum transportation growth in energy and solute particles in Prandtl martial across a vertical 3D-heated surface: Simulations achieved using by finite element approach
PublikacjaThe goal of this study is to determine the maximum energy and solute particles' transportation growth in a 3D-heated region of Prandtl martial through a dynamic magnetic field. The effects of this field on the properties of solvent molecules and heat conduction are studied. A correctly stated functional method and a finite element approach are comparable to a certain type of differential equations. In order demonstrate the effects...
-
Comparative analysis of mechanical conditions in bone union following first metatarsophalangeal joint arthrodesis with varied locking plate positions: A finite element analysis
PublikacjaFirst metatarsophalangeal joint arthrodesis is a typical medical treatment performed in cases of arthritis or joint deformity. The gold standard for this procedure is arthrodesis stabilisation with the dorsally positioned plate. However, according to the authors’ previous studies, medially positioned plate provides greater bending stiffness. It is worth to compare the mechanical conditions for bone formation in the fracture callus...
-
Simulation of hybridized nanofluids flowing and heat transfer enhancement via 3-D vertical heated plate using finite element technique
PublikacjaThe present study probed the creation of heat energy and concentrating into Newtonian liquids across vertical 3D-heated plates. The role of the Soret and Dufour theories in concentrating and energy formulas is discussed. The role of hybrid nanoparticles is introduced to illustrate particle efciency in terms of solute and thermal energy. It is removed a viscous dissipation process and a changing magnetic feld. The proposed approach...
-
The influence of the grid density of measurement points on damage detection in an isotropic plate by the use of elastic waves and laser scanning Doppler vibrometry
PublikacjaDamage detection in structural components, especially in mechanical engineering, is an 2 important element of engineering practice. There are many methods of damage detection, in which 3 changes in various parameters caused by the presence of damage are analysed. Recently, methods 4 based on the analysis of changes in dynamic parameters of structures, i.e. frequencies or mode shapes 5 of natural vibrations, as well as changes in...
-
Linear viscoelastic transversely isotropic model based on the spectral decomposition of elasticity tensors
PublikacjaThe linear viscoelasticity is still a useful model in the engineering for studying the behavior of materials loaded with different loading rates (frequencies). Certain types of materials reveal also an anisotropic behavior: fiber reinforced composites, asphalt concrete mixtures, or wood, to name a few. In general, researchers try to identify experimentally the dependence of engineering constants like: directional Young’s moduli...
-
MHD darcy-forchheimer nanofluid flow and entropy optimization in an odd-shaped enclosure filled with a (MWCNT-Fe3O4/water) using galerkin finite element analysis
Publikacja -
Smart acoustic band structures
PublikacjaSmart acoustic band structures exhibit very interesting and non-standard physical properties due to the periodic nature of their certain characteristic on different scale levels. They manifest mostly in their frequency spectra as socalled frequency band-gaps or stop-bands, what has a great impact on the behaviour of these structures in relation to the propagation of vibro-acoustic signals that can be transmitted through the structures...