Informacja

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

Wyszukujesz frazę "Costa, A." wg kryterium: Autor


Tytuł:
A 3D trabecular bone homogenization technique
Autorzy:
Marques, Marco Costa
Belinha, J.
Oliveira, A. F.
Manzanares Cespedes, M.C.
Natal Jorge, R.M.
Powiązania:
https://bibliotekanauki.pl/articles/27324130.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fabric tensor
homogenization technique
multiscale
bone
tensor tkaniny
technika homogenizacji
wieloskalowe
kość
Opis:
Purpose: Bone is a hierarchical material that can be characterized from the microscale to macroscale. Multiscale models make it possible to study bone remodeling, inducing bone adaptation by using information of bone multiple scales. This work proposes a computationally efficient homogenization methodology useful for multiscale analysis. This technique is capable to define the homogenized microscale mechanical properties of the trabecular bone highly heterogeneous medium. Methods: In this work, a morphology-based fabric tensor and a set of anisotropic phenomenological laws for bone tissue was used, in order to define the bone micro-scale mechanical properties. To validate the developed methodology, several examples were performed in order to analyze its numerical behavior. Thus, trabecular bone and fabricated benchmarks patches (representing special cases of trabecular bone morphologies) were analyzed under compression. Results: The results show that the developed technique is robust and capable to provide a consistent material homogenization, indicating that the homogeneous models were capable to accurately reproduce the micro-scale patch mechanical behavior. Conclusions: The developed method has shown to be robust, computationally less demanding and enabling the authors to obtain close results when comparing the heterogeneous models with equivalent homogenized models. Therefore, it is capable to accurately predict the micro-scale patch mechanical behavior in a fraction of the time required by classic homogenization techniques.
Źródło:
Acta of Bioengineering and Biomechanics; 2020, 22, 3; 139--152
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comparative study on the performance of radiation detectors from the HgI2 crystals grown by different techniques
Autorzy:
Martins, J. F. T.
Costa, F. E.
dos Santos, R. A.
de Mesquita, C. H.
Hamada, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/146916.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
crystal growth
iodide mercury crystal
physical vapor transport (PVT)
radiation detector
semiconductor crystal
Opis:
In this work, the establishment of a technology for HgI2 purification and crystal growth is described, aiming at a future application of this crystal as a room temperature radiation semiconductor detector. Two methods of crystal growth were studied in the development of this work: (1) physical vapor transport (PVT) and (2) saturated solution from dimethylsulphoxide (DMSO) complexes. In order to evaluate the crystals obtained using each of these methods, systematic measurements were carried out for determining the stoichiometry, structure, orientation, surface morphology and impurity of the crystal. The influence of these physicochemical properties of the crystals developed was evaluated in terms of their performance as a radiation detector. The best response to radiation was found for the crystals grown by the PVT technique. Significant improvement in the performance of HgI2 radiation detector was found, purifying the crystal by means of two successive growths by the PVT technique.
Źródło:
Nukleonika; 2012, 57, 4; 555-562
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study about the measurement method of the homogeneity of radioactivity along an iridium-192 wire used in brachytherapy
Autorzy:
Costa, O. L.
Calvo, W. A. P.
Zeituni, C. A.
Rostelato, M. E. C. M.
Moura, J. A.
Feher, A.
Souza, C. D.
Somessari, S. L.
Powiązania:
https://bibliotekanauki.pl/articles/148238.pdf
Data publikacji:
2014
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
iridium-192
iridium wire
low dose rate brachytherapy
quality control
cancer treatment
radioactive sources production
Opis:
The Nuclear and Energy Research Institute has produced, since 1998, iridium-192 wires used in low dose rate brachytherapy. In the paper the authors studied the influence of wire profile on the homogeneity distribution of radioactivity of iridium-192 along the wire. The authors propose the improvements in the quality control procedure that will provide more accurate measurement data and suggest changes in control devices.
Źródło:
Nukleonika; 2014, 59, 1; 37-39
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of isometric strength of the shoulder rotators in swimmers using a handheld dynamometer : a reliability study
Autorzy:
Coinceicao, A.
Parraca, J.
Marinho, D.
Costa, M.
Louro, H.
Silva, A.
Batalha, N.
Powiązania:
https://bibliotekanauki.pl/articles/306193.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
siłomierz
pływanie
młodzi pływacy
handheld dynamometer
prone position
young swimmers
swimming
Opis:
The purpose of this study was to determine the reliability of shoulder isometric strength assessment using the microfet 2™ dynamometer in adolescent swimmers. Methods: Twenty-nine participants (16.2 ± 1.2 years old; 59.05 ± 6.98 kg of body mass) were tested using the microfet 2™ dynamometer. Swimmers performed an isometric strength test (IST) in two distinct occasions with 7 days apart in order to calculate the reliability. All participants were asked to perform a maximal isometric contraction from the external and internal shoulder rotators in a prone body position. Results: The external and internal shoulder rotators showed an excellent intraclass correlation coefficients for both shoulders, with more than 0.90 and a low percentage of method error variation. The external/internal ratios reliability was good in dominant (ICC 0.80) and non-dominant (ICC 0.81) shoulders. The reliability using Bland–Altman method showed that systematic errors (mean difference between test-retest) were nearly zero and the 95% limits of agreement narrow, indicating a good reliability. Conclusions: It can be concluded that microfet 2™ is a reliable apparatus for measuring the strength of the external and internal rotation of the shoulder in swimmers. Its light weight and easy portable characteristics can help swimming coaches monitoring specific dry-land strength training programs for their swimmers.
Źródło:
Acta of Bioengineering and Biomechanics; 2018, 20, 4; 113-119
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Can concurrent teaching promote equal biomechanical adaptations at front crawl and backstroke swimming?
Autorzy:
Costa, M. J.
Barbosa, T. M.
Morais, J. E.
Miranda, S.
Marinho, D. A.
Powiązania:
https://bibliotekanauki.pl/articles/307054.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ekspertyza
kinematyka ruchu
pływak
expertise
kinematics
swimmer
Opis:
Purpose: The biomechanical adaptations in front crawl and backstroke swimming, as influenced by the implementation of a concurrent teaching programme were analysed. Methods: Sixteen participants (19.75 ± 1.13 years) underwent a 30 weeks intervention characterized by an increasing complexity to accomplish motor skills in the following order: (i) lower limbs propulsion; (ii) lower limbs propulsion synchronized with breathing cycle; (iii) lower limbs propulsion synchronized with one upper limb action; (iv) lower limbs propulsion synchronized with both breathing cycle and one upper limb action; (v) full swimming stroke; (vi) motor trajectory of the arms stroke. Performance and biomechanics were measured at front crawl and backstroke during three time points throughout the programme. Results: There were improvements in performance over time at front crawl (21.49 s to 19.99 s, p < 0.01) and backstroke (27.15 s to 24.60 s, p = 0.01). Significant improvements were found for velocity at front crawl (1.13 m/s to 1.22 m/s, p < 0.01) and backstroke (0.92 m/s to 1.00 m/s, p < 0.01). Stroke frequency increased at backstroke (0.64 to 0.73 Hz, p = 0.01), while the intra-cyclic variation of the velocity decreased at front crawl (0.13 to 0.12%, p = 0.02). There was also a moderate-high inter-subject variability in response to the programme. Conclusions: These findings prove that a programme of 30 weeks teaching concurrently front crawl and backstroke is effective to promote similar biomechanical adaptations in low-tier swimmers. However, each subject shows an individual response to better adapt the biomechanical actions and to reach a higher level of expertise.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 1; 81-88
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlation between clinical efficacy on pruritus and serum interleukin-31 levels in dogs with atopic dermatitis treated with lokivetmab
Autorzy:
Calesso, J.R.
Marques, V.S.
de Carvalho, O.V.
Costa-Val, A.P.
Powiązania:
https://bibliotekanauki.pl/articles/16647579.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
atopic dermatitis
interleukin-31
lokivetmab
monoclonal antibody
pruritus
Opis:
Studies on serum interleukin (IL)-31 levels in dogs with atopic dermatitis (AD) and their correlation with disease severity are limited. To the author’s knowledge, there are no studies that measured serum IL-31 in dogs treated with lokivetmab injections, a selective inhibitor of this key cytokine in pruritus. The aim of the study was to evaluate serum IL-31 levels in dogs treated with lokivetmab and correlate it with the severity of canine atopic dermatitis using the pruritus visual analog scale (pVAS) and canine atopic dermatitis extent and severity index (CADESI-04). Ten client-owned dogs diagnosed with AD received two injections of lokivetmab four weeks apart. Disease severity was assessed using the pVAS and CADESI-04 scores before and after both injections. In addition, canine serum IL-31 levels were measured at the same moments. Serum IL-31 was detected in all dogs in the study. There was a significant reduction in pVAS scores and serum IL-31 after administrations. However, there was no difference in CADESI-04 scores, and there was no significant correlation between CADESI-04 scores and serum IL-31 in dogs diagnosed with AD. Nonetheless, a significant positive correlation was observed between the pVAS scores and serum IL-31 levels with lokivetmab therapy, which reinforces the role of IL-31 in the pathogenesis of pruritus in dogs with AD. The data presented here provide further evidence that IL-31 is directly involved in pruritus pathogenesis in dogs with AD. In addition, blocking IL-31 has a significant antipruritic effect, but has no influence on skin lesion severity and extension.
Źródło:
Polish Journal of Veterinary Sciences; 2023, 26, 2; 231-238
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of an automation system for iodine-125 brachytherapy seed encapsulated by Nd:YAG laser welding
Autorzy:
Somessari, S. L.
Feher, A.
Sprenger, F. E.
Rostelato, M. E. C. M.
da Costa, F. E.
Calvo, W. A. P.
Powiązania:
https://bibliotekanauki.pl/articles/147664.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
iodine-125 seeds
prostate cancer
brachytherapy
Nd:YAG laser welding
Opis:
The aim of this work is to develop an automation system for iodine-125 radioactive seed production by Nd:YAG laser welding, which has been used successfully in low dose rate (LDR) brachytherapy treatment. This small seed consists of a welded titanium capsule, with 0.8 mm in diameter and 4.5 mm in length, containing iodine-125 adsorbed onto a silver rod. The iodine-125 seeds are implanted into the human prostate to irradiate the tumor for cancer treatment. Nowadays, the Radiation Technology Center, at Institute for Nuclear and Energy Research, Săo Paulo, Brazil (IPEN-CNEN/SP) imports and distributes 36,000 iodine-125 seeds per year, for the clinics and hospitals in the country. However, the Brazilian market potential is now over 8,000 iodine-125 seeds per month. The local production of these iodine-125 radioactive sources became a priority for the Institute, in order to reduce the price and the problems of prostate cancer management. It will permit to spread their use to a larger number of patients in Brazil. On the other hand, the industrial automation plays an important role for iodine-125 seeds in order to increase the productivity, with high quality and assurance, avoiding human factors, implementing and operating with good manufacturing practices (GMP). The technology consists of appliance electronic and electro-mechanical parts and components to control machines and processes. The automation system technology for iodine-125 seed production developed in this work was mainly assembled employing a programmable logic controller (PLC), a stepper motor, an Nd:YAG laser welding machine and a supervisory. The statistical repeatability of correctly encapsulated sealed sources with this automation system is greater than 95 per cent.
Źródło:
Nukleonika; 2011, 56, 4; 369-374
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of an irradiation system for a small size continuous run multipurpose gamma irradiator
Autorzy:
Calvo, W. A. P.
Rela, P. R.
Napolitano, C. M.
Kodama, Y.
Omi, N. M.
da Costa, F.
de Andrade e Silva, L. G.
Powiązania:
https://bibliotekanauki.pl/articles/148041.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
multipurpose irradiator
gamma irradiator
compact irradiator
cobalt-60 irradiator
gamma facility
Opis:
The Radiation Technology Center from IPEN-CNEN/SP, Brazil, developed a revolutionary design and national technology, a small-sized continuous run and multipurpose industrial gamma irradiator, to be used as a demonstration facility for manufacturers and contract service companies, which need economical and logistical in-house irradiation system alternatives. Also, to be useful for supporting the local scientific community on development of products and process using gamma radiation, assisting the traditional and potential users on process validation, training and qualification of operators and radioprotection officers. The developed technology for this facility consists of a continuous tote box transport system, comprising a single concrete vault, where the automated transport system of products inside and outside of the irradiator utilizes a rotating door, integrated with the shielding, avoiding the traditional maze configuration. Covering 76 m2 of floor area, the irradiator design is a product overlap sources and the maximum capacity of cobalt-60 wet sources is 37 PBq. The performed qualification program of this multipurpose irradiator was based on AAMI/ISO 11137 standard, which recommends the inclusion of the following elements: installation and process qualification. The initial load of the multipurpose irradiator was 3.4 PBq with 13 cobalt-60 sources model C-188, supplied by MDS Nordion – Canada. For irradiator dose optimization, the source distribution was done using the software Cadgamma developed by IPEN-CNEN/SP. The polymethylmetacrylate (PMMA) dosimeter system, certified by the International Dose Assurance Service (IDAS) of the International Atomic Energy Agency (IAEA) was used for irradiator dose mapping. The economic analysis, performance concerning with dose uniformity and cobalt-60 utilization efficiency were calculated and compared with other commercial gamma irradiators available on the market.
Źródło:
Nukleonika; 2009, 54, 2; 93-97
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Shot Peening With Glass Microspheres on the Fatigue Behavior of a Low Carbon Steel
Autorzy:
de Lacerda, J. C.
Pereira, I. R.
Costa, J. M. G.
Pinto, J. S.
Souza, H. F. M.
Fonseca, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/352156.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fatigue
shot peening
Wöhler curve
low carbon steel
glass microspheres
Opis:
The present work has the objective of studying the effect of shot peening with glass microspheres on SAE 1020 steel in its resistance to fatigue. Fatigue tests were carried out by rotary bending with load control and loading on balance in specimens with and without shot peening. A rotation speed of approximately 750 rpm (12.5 Hz) was employed in the fatigue tests. Vickers microhardness tests were performed in order to verify the surface hardening produced by shot peening with glass microspheres. Analysis of the steel surface and fatigue fractures was performed using scanning electron microscopy (SEM). Fatigue tests were performed in order to obtain S-N curves (Wöhler curves). It was observed that shot peening with glass microspheres improved the fatigue strength of the steel at high cycle.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 4; 1513-1518
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Winter Cover Crop Biomass on Summer Weed Emergence and Biomass Production
Autorzy:
Bittencourt, H.H.
Lovato, P.E.
Comin, J.J.
Lana, M.A.
Altieri, M.A.
Costa, M.D.
Gomes, J.C.
Powiązania:
https://bibliotekanauki.pl/articles/65024.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
A greenhouse assay was carried out to evaluate the effect of winter cover crop residues on spontaneous plants that commonly occur on summer annual fields in Southern Brazil. Dry shoot residues of rye (Secale cereale), vetch (Vicia villosa), fodder radish (Raphanus sativus), and a mix of the three species, were applied over pots that had been seeded with alexandergrass (Brachiaria plantaginea), hairy beggarticks (Bidens pilosa), wild poinsettia (Euphorbia heterophylla), and morning glory (Ipomoea grandifolia) at four different depths (0, 1, 2, or 4 cm). Plant emergence and biomass production were measured. Residues of rye reduced the emergence of B. plantaginea, while vetch diminished I. grandifolia and B. plantaginea emergence. Fodder radish reduced emergence of I. grandifolia. The mix of cover crops reduced emergence of I. grandifolia, B. plantaginea, and B. pilosa. None of the cover crops differed from the control on E. heterophylla emergence. The lowest yields in spontaneous plant shoot biomass were obtained from the cover with rye + vetch + fodder radish. The lowest values of root biomass occurred under cover with rye, fodder radish or the mix. Use of vetch residues decreased emergence of B. plantaginea and I. grandifolia, but enhanced biomass accumulation by the latter.
Źródło:
Journal of Plant Protection Research; 2013, 53, 3
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of disinfectant fogging procedure on dust, ammonia concentration, aerobic bacteria and fungal spores in a farrowing-weaning room
Autorzy:
Costa, A.
Colosio, C.
Gusmara, C.
Sala, V.
Guarino, M.
Powiązania:
https://bibliotekanauki.pl/articles/50123.pdf
Data publikacji:
2014
Wydawca:
Instytut Medycyny Wsi
Opis:
Introduction and Objective. In the last decades, large-scale swine production has led to intensive rearing systems in which air quality can be easily degraded by aerial contaminants that can pose a health risk to the pigs and farm workers. This study evaluated the effects of fogging disinfectant procedure on productive performance, ammonia and dust concentration, aerobic bacteria and fungal spores spreading in the farrowing–weaning room. Materials and Method. This trial was conducted in 2 identical farrowing-weaning rooms of a piggery. In both rooms, 30 pregnant sows were lodged in individual cages. At 75 days of age, the piglets were moved to the fattening room. In the treated room, with the birth of the first suckling-pig, the fogging disinfection with diluted Virkon S was applied once a day in the experimental room per 15 minutes at 11:00. The fogging disinfectant treatment was switched between rooms at the end of the first trial period. Temperature, relative humidity, dust (TSP-RF fractions and number of particles), ammonia concentration and aerial contaminants (enterococci, Micrococcaeae and fungal spores) were monitored in both rooms. Results. Ammonia concentration reduction induced by fogging disinfection was estimated 18%, total suspended particles and the respirable fraction were significantly lower in the experimental room. Fungal spores resulted in a significant reduction by the fogging procedure, together with dust respirable fraction and fine particulate matter abatement. Conclusions. The fogging disinfection procedure improved air quality in the piggery, thereby enhancing workers and animals health.
Źródło:
Annals of Agricultural and Environmental Medicine; 2014, 21, 3
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Full-fledged temporal processing : bridging the gap between deep linguistic processing and temporal extraction
Autorzy:
Costa, F.
Branco, A.
Powiązania:
https://bibliotekanauki.pl/articles/103861.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Podstaw Informatyki PAN
Tematy:
temporal processing
temporal extraction
tense
aspect
hybrid approaches
deep linguistic processing
shallow linguistic processing
Opis:
The full-fledged processing of temporal information presents specific challenges. These difficulties largely stem from the fact that the temporal meaning conveyed by grammatical means interacts with many extra-linguistic factors (world knowledge, causality, calendar systems, reasoning). This article proposes a novel approach to this problem, based on a hybrid strategy that explores the complementarity of the symbolic and probabilistic methods. A specialized temporal extraction system is combined with a deep linguistic processing grammar. The temporal extraction system extracts eventualities, times and dates mentioned in text, and also temporal relations between them, in line with the tasks of the recent TempEval challenges; and uses machine learning techniques to draw from different sources of information (grammatical and extra-grammatical) even if it is not explicitly known how these combine to produce the final temporal meaning being expressed. In turn, the deep computational grammar delivers richer truth-conditional meaning representations of input sentences, which include a principled representation of temporal information, on which higher level tasks, including reasoning, can be based. These deep semantic representations are extended and improved according to the output of the aforementioned temporal extraction module. The prototype implemented shows performance results that increase the quality of the temporal meaning representations and are better than the performance of each of the two components in isolation.
Źródło:
Journal of Language Modelling; 2013, 1, 1; 97-154
2299-856X
2299-8470
Pojawia się w:
Journal of Language Modelling
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Involvement of carbohydrates and antioxidant enzymes in the oxidative balance during drought and recovery: the eucalyptus case
Autorzy:
Correia, B.
Silva, S.
Jesus, C.
Valledor, L.
Dias, M.
Costa, A.
Santos, C.
Pinto, G.
Powiązania:
https://bibliotekanauki.pl/articles/79853.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
conference
carbohydrate
antioxidative enzyme
oxidative balance
drought
recovery
cellular function
abiotic stress
reactive oxygen species
eucalyptus
Eucalyptus globulus
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 2
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Limits in the use of cPTIO as nitric oxide scavenger and EPR probe in plant cells and seedlings
Autorzy:
D'Alessandro, S.
Posocco, B.
Costa, A.
Zahariou, G.
Lo Schiavo, F.
Carbonera, D.
Zottini, M.
Powiązania:
https://bibliotekanauki.pl/articles/80661.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
conference
nitric oxide
scavenger
plant cell
seedling
2-4-carboxyphenyl-4,4,5,5-tetramethyl imidazoline-1-oxyl-3-oxide
fluorescent dye
EPR probe
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 2
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonlinear elastic brittle damage: numerical solution by means of operator split methods
Autorzy:
Pires-Domingues, S.M.
Costa-Mattos, H.
Rochinha, F.A.
Powiązania:
https://bibliotekanauki.pl/articles/279553.pdf
Data publikacji:
1999
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
damage mechanics
finite elements
splitting technique
Opis:
The avoid the loss of well-posedness in the post localization range, some continuum damage theories for elastic materials introduce higher order gradients of the damage variable into constitutive model. Although such theories allow for mathematically correct modelling of the strain localization phenomena, they are usually considered to be very complex to handle from the numerical point of view. The present work deals with the numerical implementation of a gradient-enhanced damage theory for elastic materials. A simple numerical technique, based on the finite element method, is proposed to approximate the solution to the resulting nonlinear mathematical problems. The coupling between damage and strain variables is circumvented by means of a splitting technique.
Celem poprawności sformułowania problemu w pewnych teoriach zniszczenia do modelu konstytutywnego materiałów sprężystych wprowadza się wyższe gradienty zmiennych opisujących zniszczenie. Chociaż teorie takie umożliwiają matematycznie poprawne modelowanie zjawisk lokalizacji odkształceń, to z punktu widzenia numeryki stosowanie ich uważa się zwykle za bardzo skomplikowane. W niniejszej wersji przedstawiono zastosowanie numeryczne teorii zniszczenia z wyższymi gradientami do materiałów sprężystych. Do przybliżonego rozwiązania otrzymanych nieliniowych zadań matematycznych zaproponowano prostą metodę numeryczną opartą na metodzie elementów skończonych. Użycie metody operatorowej pozwoliło uniknąć sprężenia między zmiennymi opisującymi zniszczenie i odkształcenie.
Źródło:
Journal of Theoretical and Applied Mechanics; 1999, 4; 847-861
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
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