Anomalous Capacitive Sheath with Deep Radio Frequency Electric Field Penetration

A novel nonlinear effect of anomalously deep penetration of an external radio frequency electric field into a plasma is discribed. A self-consistent kinetic treatment reveals a transition region between the sheath and the plasma. Because of the electron velocity modulation in the sheath, bunches in the energetic electron density are formed in the transition region adjusted to the sheath. The width of the region is of order $V_{T}/\omega$, where V_{T} is the electron thermal velocity, and $\omega$ is frequency of the electric field. The presence of the electric field in the transition region results in a cooling of the energetic electrons and an additional heating of the cold electrons in comparison with the case when the transition region is neglected.Comment: 14,4 figure

Calculation of interaction of deformable designs taking into account friction in the contact zone by finite element method

© 2015 D. V. Berezhnoi and M. K. Sagdatullin. Finite element "master-slave" a technique of contact interaction of elastic deformable bodies taking into account friction in a contact zone is realized. The proved from the point of view of the solution of extreme tasks with restrictions like inequalities, projective algorithm which received the name "algorithm of a projection of the next point" was used. The model problem of contact interaction of two deformable subdesigns is solved, comparison of results with the data obtained by other authors is carried out

Numerical Investigation of Clinch Connection Manufacturing Process

© 2017 The Authors. Published by Elsevier Ltd. In the framework of the finite element method, an approach to the solution for the contact interaction problems for elastoplastic deformable bodies with considering friction in the contact zone is implemented. The geometrically nonlinear approach to the description deformation based on the definitive relationship between the increment of true stresses and deformations, a static statement is given for elastoplastic problems in three-dimensional structures, which have complex geometry. The algorithm of the solution is drawn based on "modified Lagrangian approach" to describe the motion. The problem of body deformation of steel sheets which involve clinch connection, and sample in under punch has been solved, also the distribution of residual stresses in the zone of the clinch joint has been determined

Stresses in the superflywheel

© Published under licence by IOP Publishing Ltd.We obtain exact solutions for the problem of superflywheel that is rotating around its own axis. Superflywheel is made by the nozzle at each other with tension and subsequent gluing of the family of concentric cylinders. The effect of different methods of cylinder heads on each other to the maximum stresses in the superflywheel are analyzed, estimations are given for the possible increase of its specific energy consumption. Increasing in the specific energy consumption is marked by the decreasing in relative radius of superflywheel's the inner hole and with an increase in the Poisson ratio in material of superflywheel

Investigation of the processes of deformation of super flywheels made by packing its layers on each other

© Published under licence by IOP Publishing Ltd. In the work for different cases of nozzles of layers of the super-magnetic pendulum, exact solutions in the stresses are obtained, and estimates of the increase in its specific energy are given. Dependences of tensile stresses in a tape are obtained when winding it into a super-flywheel, an increase in the specific kinetic energy in the super flywheel is observed with a decrease in the relative radius of the inner hole

Statement of the problem of numerical modelling of finite deformations

© 2014 Marat Sagdatullin and Dmitri Berezhnoi. In operation the fundamentals of a technique of numerical research of finite strains of the isotropic hyperelastic bodies, oriented on application FEM are stated. The first section is devoted kinematics of finite strains in the Lagrangian frame, tensors and measures of the strain, defining are entered speeds, various tensors of stress are reduced. In the second section physical parities of the hyperelastic isotropic environment are formulated, using the thermodynamics equations. In the third section it is reduced resolving the equation in a current configuration and the parities defining speed of change of a stress tensor of Cauchy-Euler as linear function from a tensor of a spatial gradient of speed are output

Nonlinear problem on hyperelastic deformation of the shell of average thickness FEM

© 2014 M. K. Sagdatullin and D. V. Berezhnoi. In work the numerical research of finite deformations of isotropic hyperelastic bodies is resulted. In the first section it is resulted resolving linearise the equation in a current configuration and the parities defining speed of change stress tensor Cauchy-Euler as linear function from tensor of a spatial gradient of speed are deduced. In the second section within the limits of finite-element technique numerical realization of research algorithm of finite deformations isotropic hyperelastic bodies is considered. In the third section numerical decisions of some deformation problems of hyperelastic bodies are resulted

On specific energy capacity of flywheel energy storage

© 2014 D. V. Berezhnoi, D. E. Chickrin and A. F. Galimov. The paper introduces basic methods of computational investigation for specific energy capacity of flywheel energy storage. In addition to the traditional estimation of energy capacity on the kinetic energy specific potential energy estimation of elastic strain is added. The possibilities of the use of various structural materials in the manufacture of flywheels is analyzed, some recommendations on the form of flywheel are given. "Extended" estimation of energy capacity which is used in this paper gives greater variability in the design of flywheel energy storage. In some cases it allows the reduction of the rotational speed of the rotor part of the structure

Numerical modeling of mechanical behavior of clinch connections at breaking out and shearing

© The Authors, published by EDP Sciences, 2017. This article describes an approach to constructing the defining relationships between increment of true stresses and true deformations, with considering the contact interaction of elastoplastic deformed bodies among each other. Within the framework of finite element method, solving these problems in case of "breaking out" and "shearing" in the clinch joint, the stress fields in the zone of the clinch connection are defined, and recommendations are given for realizing the process of their creation

Research of interaction of the deformable designs located in the soil

© 2014 D. V. Berezhnoi et al. In work construction of algorithm of the contact interaction based on introduction between parts of designs of a special contact layer is considered. Different variants of the deformation of the contact layer, for clarity presented by two overlays, depending on the impact of the efforts of substructures at each other. A general governing equation, which is solved on the basis of physically nonlinear problem formulated. To solve the problem, a method of solving problems in increments when iteration step the unknowns are not full of the displacement field, and their increments. It is solved model problems about modeling of stage-by-stage dredging from a foundation ditch with retaining walls