Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "metoda elementów skończonych" wg kryterium: Temat


Tytuł:
Wyznaczanie i weryfikacja parametrów turbogeneratora z symulacji polowej i polowo-obwodowej
Identification and verification of the turbogenerator parameters determined from the field and field-circuit simulation
Autorzy:
Gozdowiak, A.
Kisielewski, P.
Powiązania:
https://bibliotekanauki.pl/articles/1817718.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
turbogenerator
parametry elektromagnetyczne
metoda elementów skończonych
Opis:
Presented article shows the computation results of turbogenerator electromagnetic parameters by using finite element method. Two-dimensional field model of the turbogenerator was used during the simulations Obtained results were compared with the parameters coming from the real machine for unsaturated state.
Źródło:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały; 2014, 70, 34; 303--314
1733-0718
Pojawia się w:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ kształtu zębów stojana siłownika łożyska magnetycznego na jego parametry elektromagnetyczne
The influence of the teeth geometry in the stator on the magnetic bearing parameters
Autorzy:
Tomczuk, B.
Wajnert, D.
Powiązania:
https://bibliotekanauki.pl/articles/1812108.pdf
Data publikacji:
2012
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
aktywne łożysko magnetyczne
metoda elementów skończonych
parametry siłownika łożyska magnetycznego
Opis:
The paper presents the analysis of the stator teeth geometry impact on the parameters of the 8-pole radial magnetic bearing. In this work, such parameters as current and position stiffnesses, have been analyzed. Additionally, we propose criteria for the evaluating the characteristics of the stiffnesses, which allow to determine the optimum of the designing parameters. The research have been performed with modelling the magnetic bearing actuator boundary problem using the finite element method. Magnetic force acting on the actuator shaft has been calculated using the magnetic field distribution knowledge using Maxwell stress tensor method.
Źródło:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały; 2012, 66, 32; 218-223
1733-0718
Pojawia się w:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza przebiegu pracy turbogeneratora po wystąpieniu samoczynnego ponownego załączenia linii
Analysis of the turbogenerator work after appearance of automatic switching line
Autorzy:
Gozdowiak, A.
Kisielewski, P.
Powiązania:
https://bibliotekanauki.pl/articles/1817703.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
turbogenerator
stabilność
system elektroenergetyczny
samoczynne ponowne załączenie linii
metoda elementów skończonych
Opis:
The investigations were prepared using a valid field-circuit model of the turbogenerator. The analysis refer to an appearance of the faults in the transmission line. During this study the physical phenomena existing in turbogenerator during the faults were analyzed.
Źródło:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały; 2014, 70, 34; 295--302
1733-0718
Pojawia się w:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Jednofazowy silnik synchroniczny z magnesami trwałymi. Konstrukcja i parametry
Single-phase line start permanent magnet synchronous motor. Construction and parameters
Autorzy:
Gwoździewicz, M.
Zawilak, J.
Powiązania:
https://bibliotekanauki.pl/articles/1807519.pdf
Data publikacji:
2011
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
jednofazowy silnik indukcyjny
jednofazowy silnik synchroniczny
magnesy trwałe
metoda elementów skończonych
Opis:
The paper deals with construction of single-phase line start permanent magnet synchronous motor. Circuit-field single-phase line start permanent magnet synchronous motor model based on the mass production single-phase induction motor was applied in Maxwell ver. 14 program. Various rotor constructions were taken into account. Influence of the rotor construction on the motor properties was examined.
Źródło:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały; 2011, 65, 31; 24-34
1733-0718
Pojawia się w:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomechanics of distal femoral fracture fixed with an angular stable LISS plate
Autorzy:
Pakuła, G.
Słowiński, J.
Ścigała, K.
Powiązania:
https://bibliotekanauki.pl/articles/306403.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
femoral bone
distal femur fractures
finite element method
kość udowa
metoda elementów skończonych
Opis:
Fractures of the distal end of the femur are infrequent and constitute less than 1% of all fractures. Only 3% to 6% of femoral fractures occur at the distal end. The two groups most at risk of the said fractures are young men and older women. The aim of treatment of fractures of the distal femur is to restore normal function of the knee joint. The authors asked themselves whether, following fixation of a 33-C2 fracture (according to the AO classification) with a LISS plate, a rehabilitation program can be undertaken immediately after surgery with the implementation of active movements in the knee joint of the operated limb. In order to answer this question, we created a digital model of a fractured femur fixed with the LISS method. The model was subjected to loads corresponding to the loads generated during active lifting of a limb extended in the knee joint and during flexing of a limb in the knee joint to the 90° angle. Interfragmentary movement (IFM) is one of the key parameters taken into account in the treatment of bone fractures. It allows classification of the treatment in terms of its quality both from the mechanical and histological points of view. We analyzed interfragmentary movement in all fracture gaps. The largest recorded displacement reached in our model was 243 μm, which, in the light of the literature data, should not interfere with bone consolidation, and thus implementation of active movement in the operated knee joint (keeping in mind the simplifications of the experimental method used) is possible in the early postoperative period.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 4; 57-65
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical properties of the brain–skull interface
Autorzy:
Mazumder, M. M. G.
Bunt, S.
Mostayed, M.
Joldes, G.
Day, R.
Hart, R.
Wittek, A.
Powiązania:
https://bibliotekanauki.pl/articles/307196.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
biomechanics
brain-skull
interface
mechanical properties
FEM
biomechanika
metoda elementów skończonych
właściwości mechaniczne
Opis:
Knowledge of the mechanical properties of the brain-skull interface is important for surgery simulation and injury biomechanics. These properties are known only to a limited extent. In this study we conducted in situ indentation of the sheep brain, and proposed to derive the macroscopic mechanical properties of the brain–skull interface from the results of these experiments. To the best of our knowledge, this is the first ever analysis of this kind. When conducting in situ indentation of the brain, the reaction force on the indentor was measured. After the indentation, a cylindrical sample of the brain tissue was extracted and subjected to uniaxial compression test. A model of the brain indentation experiment was built in the Finite Element (FE) solver ABAQUSTM. In the model, the mechanical properties of the brain tissue were assigned as obtained from the uniaxial compression test and the brain-skull interface was modeled as linear springs. The interface stiffness (defined as sum of stiffnesses of the springs divided by the interface area) was varied to obtain good agreement between the calculated and experimentally measured indentor force–displacement relationship. Such agreement was found to occur for the brain-skull interface stiffness of 11.45 (mm [to -1]/ Nmm [to 2].). This allowed identification of the overall mechanical properties of the brain–skull interface.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 2; 3-11
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity study on seat belt system key factors in terms of disabled driver behavior during frontal crash
Autorzy:
Sibilski, Kamil
Małachowski, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/306683.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
niepełnosprawność
kierowca
metoda elementów skończonych
bezpieczeństwo
biomechanika
disability
driver
finite element method
safety
biomechanics
Opis:
Each year, many cars (in Poland approximately three hundred) are adopted for disabled driver, to enable them to drive the car independently. The purpose of the paper is to assess the key factors which significantly influence the disabled driver behavior during a frontal crash and have the biggest impact on the safety factors. Methods: To achieve the purpose of the paper, the finite element method was used. The authors built the numerical model which includes operation of all safety systems operating in the real car (sensors, seat belts, airbag). Using this method, the authors simulated few different cases of the frontal crash of the car driven by a person with disabilities. Results: The obtained results were: displacements, velocities and accelerations of the head, pelvis and shoulders. Additional results were also loads in the neck. Based on the achieved results, several biomechanical parameters and criterions (HIC, Nij) were computed. Conclusions: Therefore, during car adaptation for disabled drivers using a four-point seat belts system, this parameter can be optimized to reduce forces acting on the driver chest. Higher values of the force limit reduce Nij and increase HIC and contact forces between the dummy and seatbelts. Therefore, during designing of the pyrotechnic four-point seat belts system, the pretensioner characteristics should be analyzed taking all the driver’s biomechanical parameters into account.
Źródło:
Acta of Bioengineering and Biomechanics; 2019, 21, 4; 169-180
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical study of Hough technique in surgery of otosclerosis, using the finite element method
Autorzy:
Gentil, F.
Parente, M.
Martins, P.
Santos, C.
Almeida, E.
Ferreira, A.
Natali, R.
Powiązania:
https://bibliotekanauki.pl/articles/307201.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
metoda elementów skończonych
otoskleroza
wycięcie strzemiączka
strzemiączko
finite element method
otosclerosis
stapedectomy
stapedotomy
stapes
Opis:
Purpose: Otosclerosis is a metabolic bone disease of the otic capsule that can cause the stapes fixation, resulting in conductive hearing loss or, in a profound sensorineural deafness threshold. Surgery is one of the possible treatments for the otosclerosis. To repair small focus of otosclerosis in the anterior crus of the stapes, in 1960, Hough suggested the implementation of a technique in which part of the anterior crus is fractured and the stapes turned. As a result, the posterior crus of the stapes is the only connection with the inner ear. In this work, the outcome of Hough’s surgical technique was simulated. Methods: Based on computerized images, a finite element model of middle ear ossicles and tympanic membrane was created, as well as a model where the stapes has changed. The discretization of the tridimensional solid model was made using the ABAQUS software. The mechanical properties used were taken from the literature and adequate boundary conditions were applied. Results: The results obtained with the Hough technique simulation were compared with a representative model of the normal ear, taking into account the displacements obtained on the central part of the stapes footplate and the maximum principal stress in the stapes crus. Conclusions: The results obtained are closer to the normal ear model, therefore Hough technique stands out as a good option to correct small focus of otosclerosis.
Źródło:
Acta of Bioengineering and Biomechanics; 2015, 17, 4; 149-153
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical behaviour of the implant used in human hernia repair under physiological loads
Autorzy:
Szepietowska, K.
Lubowiecka, I.
Powiązania:
https://bibliotekanauki.pl/articles/307096.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
finite element modelling
hernia repair
implants
membrane structure
metoda elementów skończonych
implanty
konstrukcja membranowa
Opis:
In laparoscopic operations of abdominal hernias some recurrences still take place, even when applying a surgical mesh. This is usually caused by a failure of the connection between the tissue and the implant. The study deals with the influence of an implant’s orientation on forces in joints, which connect the mesh to human tissues. In the paper, the implant is modelled as a membrane structure within framework of the Finite Element Method. Two models are analysed: in the first one interaction between the mesh and a fascia is taken into account, in the second this interaction is not considered. Computations are conducted for two different material types of the implants: one with isotropic properties and second one with orthotropic properties. The models are validated by comparing dynamic numerical analysis with experimental outcomes, where load was simulating intraabdominal pressure during postoperative cough. Due to displacements of joints during activities like bending sideways or torsion of an abdomen, influence of kinematic extortions on forces in the joints is analysed. The outcome shows that position of the orthotropic implants is crucial and may strongly change the level of forces in the joints.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 3; 89-96
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of blocks’ topologies on endothelial shear stress observed in CFD analysis of artery bifurcation
Autorzy:
Blagojevic, M.
NIkolic, A.
Živkovic, M.
Stankovic, G.
Powiązania:
https://bibliotekanauki.pl/articles/306720.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
artery bifurcation
topology of blocks
endothelial shear stress
CFD
FEM
PAK
układ krwionośny
metoda elementów skończonych
Opis:
It is well known that endothelial shear stress affects occurrence of plaque in arteries. Lack of a method for measuring this physical quantity limits scientific understanding of this phenomenon. Application of numerical methods in this area has considerable amount of experimental verifications in terms of quantities that can be measured (velocity, pressure). On that basis we can rely on the results of endothelial shear stress calculations. The literature mainly documents the application of numerical methods to average geometries. However, arterial bifurcations are patient-specific. Moreover, occurrence of disease significantly complicates the geometry of the arteries and bifurcations. A multiblock concept provides the necessary geometrical flexibility and computational efficiency to generate patientspecific finite element models. For a particular class of problems different topologies of blocks are possible. This paper provides an overview of the possible block topologies required in finite element modeling using multiblock approach. In order to obtain accurate results of endothelial shear stress, two most general topologies are examined by numerical calculations. Favorable topology of the blocks is implemented in in-house software stl2fem.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 1; 97-104
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ warunków brzegowych na formę odkształceń drgań własnych i wymuszonych stojana silnika BLDC. Analiza numeryczna
Influence of boundary conditions on shape of deformation of free and forced vibrations of the stator structure of BLDC motor - numerical analysis
Autorzy:
Podhajecki, J.
Szymaniec, S.
Powiązania:
https://bibliotekanauki.pl/articles/1813570.pdf
Data publikacji:
2012
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
silnik bezszczotkowy prądu stałego z magnesami trwałymi
drgania
siły magnetyczne
metoda elementów skończonych
warunki brzegowe
zamocowanie
Opis:
This article presents research on the influence of the mounting on shape of deformation for free and forced vibrations in Brushless Direct Current Motor (BLDC) with permanent magnets. The status of the problem and numerical study of calculations for free and forced vibrations for different boundary conditions are shown.
Źródło:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały; 2012, 66, 32; 279-284
1733-0718
Pojawia się w:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ ekscentryczności statycznej wirnika i niejednakowego namagnesowania magnesów na postać deformacji stojana w silniku BLDC
Influence static eccentricty and uneven magnetization on form of deformation stator in BLDC motor
Autorzy:
Podhajecki, J.
Szymaniec, S.
Powiązania:
https://bibliotekanauki.pl/articles/1813571.pdf
Data publikacji:
2012
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
silnik bezszczotkowy prądu stałego z magnesami trwałymi
drgania
metoda elementów skończonych
ekscentryczność wirnika
niejednakowy poziom namagnesowania
Opis:
This article presents influence static eccentricity and uneven magnetization of the rotor on value and form of the stator deformation of Brushless Direct Current Motor (BLDC) with permanent magnets due to magnetic forces. Numerical calculations were performed for selected causes of static eccentricity and uneven magnetization of the magnets.
Źródło:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały; 2012, 66, 32; 285-290
1733-0718
Pojawia się w:
Prace Naukowe Instytutu Maszyn, Napędów i Pomiarów Elektrycznych Politechniki Wrocławskiej. Studia i Materiały
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mandibular reconstruction : biomechanical strength analysis (FEM) based on a retrospective clinical analysis of selected patients
Autorzy:
Jędrusik-Pawłowska, M.
Kromka-Szydek, M.
Katra, M.
Niedzielska, I.
Powiązania:
https://bibliotekanauki.pl/articles/306994.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
bone grafts
mandibular reconstruction
finite element method
reconstruction plates
bone healing
kości
metoda elementów skończonych
przeszczep kostny
Opis:
Restoration of mandible discontinuity defects continues as a challenge for maxillofacial surgeons. Despite the development of algorithms for reconstruction plates fixation and autogenous grafting techniques, complications are still encountered including screw loosening, bone resorption or delayed/incomplete union. The aim of the study was to analyze the possibility of obtaining bone union in the aspect of biomechanical conditions of two mandible reconstructions using an autogenous iliac crest bone graft stabilized with a reconstruction plate, and to attempt to predict patient outcomes based on strength parameters obtained by the finite element analysis. The authors of the present paper were trying to determine to what extent the reconstruction model and changes occurring in hard tissues of the bone and autogenous graft (simulated by changes in material properties) might help predict individual patient courses. The effort of reconstruction plates was defined using the values of the von Mises stress (σHMH) while the effort of bones was determined based on the values of strain intensity εint. The results of the above mentioned simulations are presented in the form of bar graphs and strain/stress distribution maps. Our strength analyses indicate that uncomplicated healing of grafts fixed with reconstruction plates requires that the initial loading of the stomatognatic system should not result in strain intensity exceeding 20–40 [×10–4]. This range of strain intensity evokes an increase in the mineral phase. The state of nonunion between the mandibular bone and the graft might result from prolonged periods of insufficient loading of the mandible during treatment.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 2; 23-31
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the influence of a metha-type metaphysical stem on biomechanical parameters
Autorzy:
Pozowski, A.
Ścigała, K.
Kierzek, A.
Paprocka-Borowicz, M.
Kuciel-Lewandowska, J.
Powiązania:
https://bibliotekanauki.pl/articles/307293.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
metaphysial stem
osteointegration
primary stability
secondary stability
stem loosening
finite element method
trwałość
metoda elementów skończonych
biomechanika
Opis:
The full postoperative loading of the limb is possible if patients are properly selected and qualified for hip arthroplasty and the requirements as to the proper position of the metaphysial stem are met. The lack of precision, and patient qualification which does not satisfy the fixed criteria may result in stem setting inconsistent with the assumptions. An analysis based on the finite element method (FEM) will enable one to find out how to plan the magnitude of operated joint loading on the basis of the position of the stem in the postoperative radiograph. By analyzing the distribution of bone tissue deformations one can identify the zones where the spongy bone is overloaded and determine the strain level in comparison with the one determined for a model of the bone with the stem in proper position. On the basis of the results obtained one can estimate the range of loads for the operated limb, which will not result in the loss of the stem’s primary stability prior to obtaining secondary stability through osteointegration. Moreover, an analysis of the formation of bone structures around the stem showed that the incorrect setting of a Metha-type stem may lead to the initiation of loosening.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 2; 13-20
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Three dimensional finite element analysis of a novel osteointegrated dental implant designed to reduce stress peak of cortical bone
Autorzy:
Zheng, L.
Yang, J.
Hu, X.
Luo, J.
Powiązania:
https://bibliotekanauki.pl/articles/306937.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
MES (metoda elementów skończonych)
implant
stomatologia
rozkład naprężeń
FEA
CT
dental implant
design
cervical cortex
stress distribution
Opis:
A new type of dental implant was designed as multi-component mainly including inset and abutment between which a gap was introduced to guide the force to transmit from the cancellous bone to cortical bone, with the intention to lower the stress peak at cortical bone. By the way of finite element analysis (FEA) associated with advanced computer tomography (CT) and 3D model reconstruction technology to construct precise mandible model, biomechanical aspects of implant were investigated. Compared with traditional implant that created stress dominantly at cortical bone, stress peak at the implant/bone interface in the cervical cortex decreased sharply (about 51%) for new type of implant. Furthermore, varying implant shape and gap dimensions to optimize the design of this new implant was performed. Optimization results revealed that: 1) screwed cylindrical implant is superior to tapered, stepped and smooth cylindrical implant in effectively decreasing the stress peak of bone; 2) deepening and widening gap would contribute to the decline of stress peak, but at the cost of break and destruction of the inset; 3) suitable gap size with the depth of 7mm and width of 0.3mm would be applicable. This work may provide reference forclinical application of dental implant.
Źródło:
Acta of Bioengineering and Biomechanics; 2014, 16, 3; 21-28
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The BEM-FDM model of thermal processes proceeding in the domain of the human finger
Autorzy:
Majchrzak, E.
Mochnacki, B.
Tarasek, D.
Dziewoński, M.
Powiązania:
https://bibliotekanauki.pl/articles/307248.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
przepływ ciepła
przepływ krwi
metoda elementów skończonych
termogram
bioheat transfer
countercurrent blood flow
boundary element method
thermograms
Opis:
Purpose: The problem of the numerical modeling of thermal processes proceeding in the non-homogeneous domain of the human finger is discussed. The domain considered constitutes the assembling of soft and bone tissues and the system of supplying blood vessels (arteries and veins). The mathematical description of the process analyzed corresponds to the so-called vascular models. Methods: At the stage of numerical modeling the algorithm being the composition of the boundary element method (BEM) and the finite difference method (FDM) is applied. Results: The algorithm presented allows one to determine the steady state temperature field in the finger domain in natural convection conditions. To verify the effectiveness and exactness of the method of the problem solution, the thermal imaging measurements of the finger surface temperature have been done. Conclusions: The compatibility of numerical and experimental results (the natural convection conditions) has proved to be quite satisfactory. It is possible to use the algorithm proposed for the modeling of thermal processes proceeding in the conditions of low or high ambient temperatures and the big values of heat transfer coefficients. The impact of protective clothing on the temperature field in the domain of the finger can also be analyzed.
Źródło:
Acta of Bioengineering and Biomechanics; 2015, 17, 4; 85-96
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of different material theories used in a FE model of a lumbar segment motion
Autorzy:
Gohari, E.
Nikkhoo, M.
Haghpanahi, M.
Parnianpour, M.
Powiązania:
https://bibliotekanauki.pl/articles/307482.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
creep
dynamic loading
finite element method
lumbar motion segment
poroelastic
viscoelastic
pełzanie
porosprężystość
lepkosprężystość
metoda elementów skończonych
Opis:
In this study, a nonlinear poroelastic model of intervertebral disc as an infrastructure was developed. Moreover, a new element was defined consisting a disc (Viscoelastic Euler Beam Element) and a vertebra (Rigid Link) as a unit element. Using the new element, three different viscoelastic finite element models were prepared for lumbar motion segment (L4/L5). Prolonged loading (short-term and longterm creep) and cyclic loading were applied to the models and the results were compared with results of in vivo tests. Simplification of the models by using the new element leads to reduction of the runtime of the models in dynamic analyses to few minutes without losing the accuracy in the results.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 2; 33-41
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of wear of polyethylene hip joint cup related to its positioning in patient’s body
Autorzy:
Rońda, J.
Wojnarowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/307555.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
hip joint endoprosthesis
wear
coefficient of wear
finite element method
proteza stawu biodrowego
metoda elementów skończonych
zużycie
Opis:
Polyethylene parts of endoprosthesis are the weakest parts of each medical implant. They can be worn out within several years. During this period, a patient can enjoy good physical efficiency until the wear of polyethylene part limits his/her mobility. Then the reoperation is necessary and positioning of all parts of endoprosthesis has an effect on future patient’s mobility and durability of implant. Elements of endoprosthesis during exploitation are heavily loaded both by normal and tangential forces and moments. In this paper, the dependence of wear of polyethylene cup on its positioning in pelvis is the major problem. Wear of the cup is determined by two measures: the depth and volume of a material rubbed off from the contact surface. The sensitivity of the depth of rubbing off is evaluated relative to two angles of anteversion and abduction, and radii of the cup. Numerical results are obtained by using Abaqus FE system with data related to patient’s activity identified on the basis of medical reports.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 1; 77-86
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A simple method of incorporating the effect of the Uniform Stress Hypothesis in arterial wall stress computations
Autorzy:
Joldes, G. R.
Noble, C.
Polzer, S.
Taylor, Z. A.
Wittek, A.
Miller, K.
Powiązania:
https://bibliotekanauki.pl/articles/306753.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
naprężenia własne
metoda elementów skończonych
ściana tętnicy
Uniform Stress Hypothesis
residual stress
finite element method
arterial wall stress
Opis:
Residual stress has a great influence on the mechanical behaviour of arterial wall. Numerous research groups used the Uniform Stress Hypothesis to allow the inclusion of the effects of residual stress when computing stress distributions in the arterial wall. Nevertheless, the available methods used for this purpose are very expensive, due to their iterative nature. In this paper we present a new method for including the effects of residual stress on the computed stress distribution in the arterial wall. Methods: The new method using the Uniform Stress Hypothesis enables computing the effect of residual stress by averaging stresses across the thickness of the arterial wall. Results: Being a post-processing method for the computed stress distributions, the proposed method is computationally inexpensive and, thus, better suited for clinical applications than the previously used ones. Conclusions: The resulting stress distributions and values obtained using the proposed method based on the Uniform Stress Hypothesis are very close to the ones returned by an existing iterative method.
Źródło:
Acta of Bioengineering and Biomechanics; 2018, 20, 3; 59-67
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of surgical drills wear on thermal process generated in bones
Autorzy:
Basiaga, M.
Paszenda, Z.
Szewczenko, J.
Kaczmarek, M.
Powiązania:
https://bibliotekanauki.pl/articles/306823.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
surgical drills
finite element method
thermal analysis
bone surgery
wiertło chirurgiczne
analiza termiczna
metoda elementów skończonych
chirurgia kostna
Opis:
The influence of the wear rate of drills used in bone surgery on the temperature distribution in the femur models (Sawbones) is presented in the paper. Surgical drills of diameter d = 4.5 mm and diverse edge geometry (90° and 120°) were selected for the study. In order to carry out thermal analysis with the use of finite element, experimental studies of wear process were necessary. These studies, among others, consisted in determination of average values of axial forces and cutting torques as a function of the number of drilled holes. The study showed an impact of the drill geometry on values that describe cutting process. It was found that the greatest values of torques and axial cutting forces occur in drills of point angle of 120°. Next, in order to determine the effect of wear rate on the generation of temperature in the cutting zone, thermal analysis of the drilling process using the finite element method was carried out. It was found that higher temperatures in the bone are observed for drilling with the use of the drill of point angle equal to 120°, as in the experimental study. For the tools of such edge geometry the wear of cutting edge is more intensive and the generated temperature in femur for the wear land VBB = 0.32 mm has reached the critical value associated with the process of thermal necrosis.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 4; 19-23
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mock-up in hip arthroplasty pre-operative planning
Autorzy:
Zanetti, E. M.
Bignardi, C.
Powiązania:
https://bibliotekanauki.pl/articles/306839.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
hip steam
primary stability
finite element method
bone-implant interface
kości
współpraca na powierzchni kość-implant
metoda elementów skończonych
Opis:
The correct estimation of stem boundary conditions in hip arthroplasty cannot be performed simply by subtracting the prosthesis volume from the bone volume: the stem implant path needs to be taken into account. Digital mock-up is a technique commonly applied in the automotive field which can be used for this aim. Given a certain femur, a stem, and an implantation path, the volume of the removed bone stock can be evaluated, as well as the final contact area between the bone and the stem, and, section by section, the residual cortical bone thickness. The technique proved to be useful: if the stem implant path is not considered, the removed bone stock volume can be underestimated up to 6%, while the contact area extension can be overestimated up to 28%. On the whole, a new methodology has been set up and tested, which can be usefully employed to accurately establish stem boundary conditions in the pre-operative planning stage, and in order to perform a reliable structural stress analysis. The methodology implemented here by experienced researchers can be made available to surgeons, setting up an apposite software suite.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 3; 123-128
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomechanical study on the changes of stress in temporomandibular joints after the orthognathic surgery in patients with mandibular prognathism: a 3D finite element study
Autorzy:
Shu, Jingheng
Wang, Quanyi
Ma, Hedi
Teng, Haidong
Zheng, Tinghui
Liu, Zhan
Powiązania:
https://bibliotekanauki.pl/articles/27324150.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
temporomandibular joint
finite element method
mandibular prognathism
temporomandibular disorders
staw skroniowo-żuchwowy
metoda elementów skończonych
prognatyzm żuchwy
zaburzenia skroniowo-żuchwowe
Opis:
Purpose: This study aimed to analyze the changes of the stress distributions in TMJs for the pre- and postoperative patients with mandibular prognathism under unilateral occlusions, a frequent occlusion in mastication. Methods: Pre- and six-mouth postoperative cone-beam computed tomography images of thirteen patients diagnosed with mandibular prognathism were scanned and used to construct complete maxillofacial models, assigned as the Pre and Post group, respectively. Another ten asymptomatic individuals were defined as the Control group. The inhomogeneous properties were assigned to the models. The muscle forces and boundary conditions corresponding to left and right unilateral occlusions were applied on the models. The analysis of variation (ANOVA) was chosen for the comparison among the groups. Results: The results showed that the Pre group had abnormal stress distributions ang higher stress level in TMJs, compared with those of the Post and Control groups. Moreover, from clinical cases, symptoms of temporomandibular disorders (TMDs) always followed with increased stresses. Conclusion: Generally, orthognathic surgeries could improve the stress distribution in TMJs of the patients with mandibular prognathism under the unilateral occlusions. However, the postoperative complications, especially symptoms of TMD, were closely related to changes of stress for patients with mandibular prognathism after orthognathic surgeries. Individual virtual surgery and finite element analysis should be conducted to prevent complications in TMJ.
Źródło:
Acta of Bioengineering and Biomechanics; 2020, 22, 2; 155--163
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shape optimisation of a ventricular assist device using a VADFEM computer program
Autorzy:
Kopernik, M.
Powiązania:
https://bibliotekanauki.pl/articles/307277.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ventricular assist device
finite element method
optimisation
goal function
multi-scale modelling
metoda elementów skończonych
optymalizacja
komorowe wspomaganie pracy serca
Opis:
The Polish ventricular assist device, POLVAD_EXT, is made of a polymer designed to be covered with a nanocoating of titanium nitride to improve haemocompatibility. A loss of cohesion can occur between the coating and the substrate. An analysis of stress and strain states in a multi-scale model of the blood chamber was performed in the finite element computer program, VADFEM. The multiscale model is composed of a macro model of the blood chamber and a micro model of the titanium nitride (TiN) deposited on the polymer. The finite element method and the goal function, based on the triaxiality factor, are used to solve the problems formulated. The theories of non-linear elasticity and elasto-plasticity are applied. The goal of the paper is to optimise the construction of the POLVAD_EXT with respect to shape parameters.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 3; 81-87
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomechanical analysis of asymmetric mesio-distal molar positions loaded by a symmetric cervical headgear
Autorzy:
Kizilova, N.
Geramy, A.
Romashov, Y.
Powiązania:
https://bibliotekanauki.pl/articles/307374.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
metoda elementów skończonych
FEM
system docisku
asymetria
ortodoncja
finite element method
force system
asymmetry
Yaw Moment
orthodontic tooth movement
headgear
Opis:
Purpose: The plane 2d model and 3d finite element model of the headgear attached to two molars with different mesio-distal location are studied to show the asymmetric mechanical effects produced by symmetrically loaded headgear. In daily dental practice the asymmetrical location of molars is usually ignored. Methods: Six 3D finite element models of a symmetric cervical headgear were designed in SolidWorks 2011. The models showed symmetric molar position (model 1), 0.5 to 2 mm of anterior-posterior molar difference (models 2-5) and a significant asymmetry with 10 mm of difference in the locations (model 6). The head gear was loaded with 3N of force applied at the cervical headgear. The forces and moments produced on terminal molars are assessed. Results: It is shown the difference between the forces acting at the longer and shorter outer arms of the headgear increases with increase in the distance. The significant numeric difference in the forces has been found: from 0.0082 N (model 1) to 0.0324 N (model 5) and 0.146 N (model 6). These small forces may produce unplanned distal tipping and rotation of the molars around their vertical axes. The most important funding was found as a clockwise yaw moment in the system when is viewed superio-inferiorly. The yaw moment has been computed between -0.646 N•mm (model 1) and -1.945 N•mm (model 5). Conclusions: Therefore even small asymmetry in location of molars loaded by a symmetric cervical headgear will produce undesirable move-ment and rotation of the teeth that must be taken into account before applying the treatment.
Źródło:
Acta of Bioengineering and Biomechanics; 2016, 18, 4; 97-106
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reduction of derivative pipeline effort in water turbine
Autorzy:
Flis, L.
Dobrociński, S.
Kiełczyński, W.
Powiązania:
https://bibliotekanauki.pl/articles/178848.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
obciążenia hydrostatyczne
rurociąg derywacyjny
wytężenie rurociągów
turbina wodna
MES (metoda elementów skończonych)
hydrostatic load
water turbine
derivative pipeline
pipeline effort
FEM
Opis:
The article presents an approach to evaluate and reduce the effort of the derivative pipeline in a water turbine of a hydroelectric power station in its vulnerable spots. Potential places of the biggest effort of the structure, as well as the coefficient of displacement and safety factor related to them were identified using FEM numerical method. Pipeline reinforcement was designed and made based on FEM analysis and non-destructive tests.
Źródło:
Studia Geotechnica et Mechanica; 2013, 35, 1; 93-108
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies