Contact Displacements of Spatial Contact of a Rough Body and a Body with Coating

This paper is an example of the application of a structural nonlocal theory to the solution of the contact problem of a rough curvilinear body with plastic coating on another body. The main goal of these investigations is the creation of extrapolation methods of results of theoretical investigations from flat surfaces to any tribological system with curvilinear macro surfaces. This paper deals with the application of a phenomenological approach which is based on using the middle layer. It allows to represent a contact problem for real bodies as a superposition of two problems. The first one is the problem of penetration of rigid roughness in a plastic coating taking into account statistical characteristics of the surface. The second problem is the elastic deformation of smooth bodies with a circular area of interaction. The external load is supposed to be constant. The solution is obtained with the help of the contracting mapping principle and a simple iteration method. It is established that the first analytical approximation of solutions of the corresponding equations is useful for practical applications with sufficient accuracy. The paper deals with the case of plastic penetration of a surface asperity only when the macro contact stress is less than the yield stress of the coating, i.e. without macro plastic penetration of curvilinear bodies into this coating

Effect of Surface Rheology on Contact Displacement

  &nbsp

Mathematical Modelling of Spatial Contact Interaction of a System of Finite Cylindrical Bodies

  &nbsp

Теоретический метод управления расходом перекачиваемой среды по положению запирающих элементов трубопроводной арматуры

Any object located in the pipeline, including the flow meter, leads to a drop in pressure in the pipeline and the need to increase the power of the pumps. Therefore, it seems promising to reduce energy consumption for pumping fluid in the pipeline by reducing the number of flow meters installed after shut-off and control valves and to predict the flow rate of the pumped medium by the position of the locking element in the valve. This will also lead to a reduction in the cost of transporting media by reducing the number of metering devices. In order to solve this complex problem in pipeline transport, the article solves a number of regional problems of hydromechanics based on the finite element method. In order to simplify the acquaintance with these solutions, as well as their practical application by engineers, the article proposes «parametric stationary vortex flow models in such types of shut-off and control valves as a ball valve, butterfly valve, wedge gate valve, angle valve. Without prejudice to generality of the technique, water is considered as an example of a pumped medium. The analysis was performed using FLOTRAN CFD software of ANSYS10 ED program». The article describes in detail the capabilities of both the graphical interface and the command line. Creating models is accompanied by full comments on the actions, which allows any user to master these models. All stages of building models are considered in detail: construction of a solid-state model, selection of elements, appointment of properties of the pumped media, appointment of boundary conditions, as well as solving the problem and viewing the results. «It has been established that the flow rate of the medium is affected both by the geometry of the considered types of shut-off and control valves», and the position of the locking element. The technique can be applied to any designs of pipe fittings associated with calculation of movement of a viscous fluid.Любой объект, расположенный в трубопроводе, в том числе расходомер, приводит к падению давления в трубопроводе и необходимости повышения мощности насосов. Поэтому представляется перспективным снизить энергозатраты на перекачку среды в трубопроводе за счёт уменьшения количества расходомеров, устанавливаемых после запорно-регулирующей арматуры, и прогнозировать расход перекачиваемой среды по положению запирающего элемента в арматуре. Это приведёт также к уменьшению затрат на транспортировку сред за счёт уменьшения количества приборов учёта. В статье с целью решения данной комплексной проблемы на трубопроводном транспорте на основе метода конечных элементов решается ряд краевых задач гидромеханики. С целью упрощения знакомства с данными решениями, а также их применения на практике инженерами, в статье предложены «параметрические модели вихревого стационарного течения в таких видах запорно-регулирующей арматуры, как шаровой кран, дисковый затвор, клиновая задвижка, угловой клапан. Без ущерба общности методики, в качестве примера перекачиваемой среды рассматривается вода. Анализ выполнен средствами FLOTRAN CFD программы ANSYS10 ED». В статье детально описываются возможности как графического интерфейса, так и командной строки. Создание моделей сопровождается полными комментариями о действиях, что позволяет любому пользователю освоить данные модели. Подробно рассмотрены все этапы построения моделей: построение твёрдотельной модели, выбор элементов, назначение свойств перекачиваемых сред, назначение краевых условий, а также решение задачи и просмотр результатов. «Установлено, что на расход среды оказывает влияние, как геометрия рассмотренных видов запорно-регулирующей арматуры, так» и положение запирающего элемента. Методика может быть применена для любых конструкций трубопроводной арматуры, связанных с расчётом движения вязкой жидкости

Networking in the context of the organization and development system practices

In the article, the many years of work on the development of a system of practices with a focus on the changing environment of the organization, the dynamics of the regulatory requirements, the possibility of attracting stakeholders from different spheres of activity. The authors summarize the experience of interaction with various educational institutions, commercial entities to achieve regulatory documents the goals and objectives of practice.Дается характеристика многолетней работы по развитию системы практик с ориентацией на меняющиеся условия организации, динамику нормативных требований, возможности привлечения заинтересованных участников из разных сфер деятельности. Обобщается опыт взаимодействия с различными учебными заведениями, коммерческими структурами для достижения поставленных нормативными документами целей и задач практики

Isotope analysis in central heavy ion collisions at intermediate energies

Symmetry energy is a key quantity in the study of the equation of state of asymmetric nuclear matter. Heavy ion collisions at low and intermediate energies, performed at Laboratori Nazionali di Legnaro and Laboratori Nazionali del Sud, can be used to extract information on the symmetry energy coefficient Csym, which is currently poorly known but relevant both for astrophysics and for structure of exotic nuclei.Comment: 2 pages, 1 figure. Proceedings of 7th International Conference on Radioactive Nuclear Beams (RNB7), to be published in The European Physical Journal

GARFIELD + RCo Digital Upgrade: a Modern Set-up for Mass and Charge Identification of Heavy Ion Reaction Products

An upgraded GARFIELD + Ring Counter (RCo) apparatus is presented with improved performances as far as electronics and detectors are concerned. On one side fast sampling digital read out has been extended to all detectors, allowing for an important simplification of the signal processing chain together with an enriched extracted information. On the other side a relevant improvement has been made in the forward part of the setup (RCo): an increased granularity of the CsI(Tl) crystals and a higher homogeneity in the silicon detector resistivity. The renewed performances of the GARFIELD + RCo array make it suitable for nuclear reaction measurements both with stable and with Radioactive Ion Beams (RIB), like the ones foreseen for the SPES facility, where the Physics of Isospin can be studied.Comment: 13 pages, 19 figures - paper submitted to Eur. Phys. J.