Mechanics

On a form of the first variation of the action integral over a varied domain

Authors: Kovalev V. A., Radaev Y. N.

Field theories of the continuum mechanics and physics based on the least action principle are considered in a unified framework. Variation of the action integral in the least action principle corresponds variations of physical fields while space-time coordinates are not varied. However notion of the action invariance, theory of variational symmetries of action and conservation laws require a wider variation procedure including variations of the space-time coordinates.

The loading parameters calculation of a hollow sphere at the large elastocreep deformations

Authors: Murashkin E. V.
We presented a model of large elastocreep deformations. Separation of Almansi strain tensor is determined by the quadratic form of reversible and irreversible components. We consider spherically symmetric deformation of a hollow sphere in the steady creep process. Numerical solution of boundary-value problem was obtained. A method for determining loading force on the deformed state was proposed. Functions of the external loading force according to the laws of a given change in the displacement field were constructed.
 

The restoration of functional relationships with a given singularity

Authors: Faizullin R. T., Faizullin R. R.

 Provided methods recovery of functional dependence with a specified discontinuity. Application of the algorithm of building function with given discontinuity is shown. The first method is based on a formal function minimization by random search. The second uses the information content of the data. 

The stability of the constructive-orthotropic heterogeneous cylindrical shell under uneven radial load

Authors: Mochalin A. A.

On the base haft-momentum Vlasov theory the problem of stability of cylindrical homogeneas shell with variation of thicknees atv radial symmetrical ractial pressure variated onalong axe distance. At one reletion between thickness and pressure values the accurate solution was produced for one values in pressure variation law when stability of shell is sailed. 

Dual matrix and biquaternion methods of solving direct and inverse kinematics problems of manipulators for example Stanford robot arm. II

Authors: Lomovtseva E. I., Chelnokov Y. N.

The methology of solving the inverce kinematics problem of manipulators by using biquaternion theory of kinematics control is shown on the example of Stanford robot arm. Solving of the inverce kinematics problem of Stanford robot arm is performed using the simplest control law. The analysis of numerical solution results is made. The efficacy of applying the theory of kinematics control for solving the inverce kinematics problem of manipulators is proved.

A mathematical theory of plane harmonic coupled thermoelastic waves in type-I micropolar continua

Authors: Kovalev V. A., Murashkin E. V., Radaev Y. N.

The present paper is devoted to an analysis of plane harmonic coupled thermoelastic waves of displacements, microrotations and temperature propagating in continua.The analysis is carried out in the framework of linear type-I (GNI/CTE) theory of thermoelastic micropolar continuum. Additional microrotations and moment stresses are taken into consideration. Propagating wave surfaces of weak discontinuities of displacements, microrotations, and temperature are studied by compatibility conditions technique due to Hadamard and Thomas.

The new approach to investigation of multilayer graphene mechanical properties by the finite-element method

Authors: Glukhova O. E., Dol A. V., Kolesnikova A. S., Shunaev V. V.

A new approach to investigate the mechanical properties of multilayer graphene was suggested. The method is based on the idea that the van der Waals interaction between the graphene sheets can be simulated by a fictitious layer of continuum. The stress-strain state of multilayer graphene is described by stationary equations of Navier–Lame. This approach has been successfully tested on graphene deflection. The graphene layers were considered as linear-elastic material.

Numerical analysis of renal artery pathologies

Authors: Schuchkina O. A., Голядкина А. А., Aristambekova A. V., Potapov D. Y.

 Mathematical modeling based on experimental data (ultrasonic imaging, angiography, 3D reconstruction via spiral computed tomography) was performed. Anatomically precise model of renal artery was created. Basic principles of blood flow dynamics with stressstrain state of artery walls were studied for normal, pathologic renal arteries and arteries with hemostasis of intraorganic branches. 

Graph approach for finite-element based model of an elastic body under conditions of axisymmetric deformation

Authors: Tirimov A. A.

 A numerical method for analysis of the stress – strain state of elastic media based on a discrete model in form of directed graph is suggested. To analyze a deformable body using the graph approach, we partitione a solid body on elements and replace each element by its model in the form of an elementary cell. The matrices, presenting several structure elements of the graph, and the equations, describing the elementary cells, contribute to deriving the constitutive equations of the intact body.

The transformation of longitudinal the strain wafe having a linear form and increasing intensity in conjugation of rods with elastic gacket

Authors: Manzhosov V. K., Novikova I. A.

The paper gives a review of transformation of longitudinal strain wave at the boundary of heterogeneous rods with elastic gasket. The article describes a technique for calculating the transformation of the strain wave of linear form. Parameters of the wave, which have passed through connection of rods are defined. 

Pages