Damage in textile laminates of various inter-ply shift

Deformation mechanisms and failure of textile laminates are strongly affected by inter-layer configurations – a mutual shift of the plies. To model it within a traditional framework, one must construct a representative volume element (RVE), which includes all the plies. This is a time consuming and computationally expensive work. As an alternative, the paper suggests boundary conditions (BC) imitating the interaction with the surrounding non-periodic media. This makes possible analysis on a single unit cell of one ply. The proposed BC respect inter-ply configurations, account for the number of plies, distinguish the ply position, and reproduce the meso stress state with a good accuracy. The BC are constructed through (1) averaging of the known periodic solutions with respect to the ply shifts, (2) separation of the solution to the outer and inner ply cases, (3) energy equilibrium of heterogeneous and effective media. The unit cell finite element (FE) modelling is validated by reference full scale solution on the entire laminate

Fibre distribution inside yarns of textile composite: gemetrical and FE modelling

This article addresses the experimental investigation and modelling of the uneven fibre distribution inside yarns of a textile composite. The test data is given for the tri-axial carbon-fibre braid; a considerable irregularity is revealed for the fibre distribution along and across the yarns. The importance of this effect for the damage resistance is illustrated with a simple finite-element (FE) model. The geometrical modelling of the internal geometry is also discussed

Nanosize phases formation under low carbon steel thermomechanical strengthening

The quantitative regularities of structure phase states formation in different Hbeam cross sections under accelerated cooling in different regimes are established. The gradient structure-phase states formation being characterized by the regular change of dislocation substructure parameters, nanosized range -phase fragments and cementite particles on cross section are revealed by methods of transmission electron diffraction microscopy. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2068

Universal structure of subleading infrared poles at strong coupling

Recently a concise expression for the subleading infrared singularity of dimensional-regularized gauge theories has been proposed. For conformal theories, such relation involves a universal eikonal contribution plus a non-eikonal contribution, related to the subleading term in the anomalous dimension of twist two operators with large spin. In this note we make use of the AdS/CFT correspondence in order to check such conjecture at strong coupling for the case of N=4 SYM.Comment: 13 page

The multifrequency Siberian Radioheliograph

The 10-antenna prototype of the multifrequency Siberian radioheliograph is described. The prototype consists of four parts: antennas with broadband front-ends, analog back-ends, digital receivers and a correlator. The prototype antennas are mounted on the outermost stations of the Siberian Solar Radio Telescope (SSRT) array. A signal from each antenna is transmitted to a workroom by an analog fiber optical link, laid in an underground tunnel. After mixing, all signals are digitized and processed by digital receivers before the data are transmitted to the correlator. The digital receivers and the correlator are accessible by the LAN. The frequency range of the prototype is from 4 to 8 GHz. Currently the frequency switching observing mode is used. The prototype data include both circular polarizations at a number of frequencies given by a list. This prototype is the first stage of the multifrequency Siberian radioheliograph development. It is assumed that the radioheliograph will consist of 96 antennas and will occupy stations of the West-East-South subarray of the SSRT. The radioheliograph will be fully constructed in autumn of 2012. We plan to reach the brightness temperature sensitivity about 100 K for the snapshot image, a spatial resolution up to 13 arcseconds at 8 GHz and polarization measurement accuracy about a few percent. First results with the 10-antenna prototype are presented of observations of solar microwave bursts. The prototype abilities to estimate source size and locations at different frequencies are discussed

The structure and properties of a hypoeutectic silumin subjected to complex electron–ion-plasma processing

The layer-by-layer analysis of structural–phase states and tribological properties of hypoeutectic АК10М2Н-type silumin at the depth up to 170 μm after the complex processing is carried out by the state-of-the-art methods of physical materials science. It involves the electroexplosion alloying with titanium and yttrium-oxide powder in different ratios followed by electron-beam processing.Методами сучасного фізичного матеріалознавства проведено пошарову аналізу структурно-фазових станів і трибологічних властивостей доевтектичного силуміну марки АК10М2Н на глибині до 170 мкм після комплексного оброблення. Воно полягало в електропідривному леґуванні титаном і порошком оксиду ітрію в різних співвідношеннях з подальшим електронно-пучковим обробленням.Методами современного физического материаловедения проведён послойный анализ структурно-фазовых состояний и трибологических свойств доэвтектического силумина марки АК10М2Н на глубине до 170 мкм после комплексной обработки. Она заключалась в электровзрывном легировании титаном и порошком оксида иттрия в разных соотношениях с последующей электронно-пучковой обработкой

Modification of structure and surface properties of hypoeutectic silumin by intense pulse electron beams

Methods of contemporary physical materials science are applied for the analysis of structural and phase states, tribological and mechanical properties of hypoeutectic silumin treated by electron beams with parameters as follow: energy density — 10– 35 j/cm2, pulse duration — 10 μs, number of pulses — 3, pulse-repetition frequency — 0.3 Hz. The initial structure of silumin comprises grains of aluminiumbased solid solution, eutectic grains, inclusions of silicon and intermetallic compounds with different shapes and sizes.Методами сучасного фізичного матеріялознавства виконано аналізу структурнофазових станів, трибологічних і механічних властивостей доевтектичного силуміну, що піддається електронно-пучковому обробленню (ЕПО) за наступних пара метрів пучка: густина енергії — 10–35 Дж/см2, тривалість імпульсу — 10 мкс, кількість імпульсів — 3, частота проходження — 0,3 Гц. У початковому стані структуру силуміну сформовано зернами твердого розчину на основі алюмінію, зернами евтектики, включеннями кремнію й інтерметалідів різної форми та розмірів.Методами современного физического материаловедения выполнен анализ структурно-фазовых состояний, трибологических и механических свойств доэвтектического силумина, подвергнутого электронно-пучковой обработке (ЭПО) со следующими параметрами пучка: плотность энергии — 10–35 Дж/см2, длительность импульса — 10 мкс, количество импульсов — 3, частота следования — 0,3 Гц. В исходном состоянии структура силумина сформирована зёрнами твёрдого раствора на основе алюминия, зёрнами эвтектики, включениями кремния и интерметаллидов различной формы и размеров

Подвывих и вывих бедра у детей с последствиями спинномозговых грыж (обзор литературы)

Subluxation or dislocation of the hip joint develops in 30-50% children with spina bifida during the first 2-3 years of life. These problems results from force disbalance between muscle group and other structural changes of the hip and pelvis components of the joint. The goal of treatment subluxation and dislocation of the hip joint in children with spina bifida is to make comfortable daily functions, eliminate the pain, provide the mobility and social independent. Management of subluxation and dislocation in children with spina bifida had changed in the last years because of the analysis long-term results. Indications for surgical treatment were determined more clearly, what made the results of treatment better.У 30-50% детей с последствиями спинномозговых грыж развивается подвывих или вывих в тазобедренном суставе в течение первых 2-3 лет жизни. Эти проблемы являются результатом дисбаланса сил между мышечными группами и другими ассоциированными структуральными изменениями бедренного и тазового компонентов сустава. Целью лечения подвывиха и вывиха бедра у пациентов с последствиями спинномозговой грыжи являются создание им удобства осуществления функций, ликвидация болевого синдрома, обеспечение мобильности и социальной независимости. Тактика лечения подвывиха и вывиха бедра у таких детей значительно изменилась в последние годы в связи проведенным анализом отдаленных результатов. Показания к оперативному лечению были определены более четко, что улучшило результаты

N=2 Super-Born-Infeld from Partially Broken N=3 Supersymmetry in d=4

We employ the non-linear realization techniques to relate the N=1 chiral, and the N=2 vector multiplets to the Goldstone spin 1/2 superfield arising from partial supersymmetry breaking of N=2 and N=3 respectively. In both cases, we obtain a family of non-linear transformation laws realizing an extra supersymmetry. In the N=2 case, we find an invariant action which is the low energy limit of the supersymmetric Born-Infeld theory expected to describe a D3-brane in six dimensions.Comment: 15 pages, no figures, RevTeX4, new comments and references added, some equations corrected, discussion at end of sec. 3 change