Mechanics

About a problem of spacecraft's orbit optimal reorientation

Authors: Pankratov I. A., Sapunkov Y. G., Chelnokov Y. N.

 The problem of optimal reorientation of the spacecraft's orbit is solved with the help of the Pontryagin maximum principle and quaternion equations. Control (thrust vector, orthogonal to the orbital plane) is limited in magnitude. Functional, which determines a quality of control process is weighted sum of time and module (or square) of control. We have formulated a differential boundary problems of reorientation of spacecraft's orbit.

Research of consequences of tether's jamming in the task of payload delivery from an orbit

Authors: Ledkov A. S., Dyukov D. I.

In article the off-normal situation of tether's jamming at the decision of the task of payload delivery from an orbit by means of a tether is considered. The mathematical model described the space tether system consisting of the basic space vehicle, the tether and the payload is used. At creation of model the mass and damping properties of the tether weren't considered. It is supposed that basic space vehicle moves on a circle orbit.

Thermomechanical orthogonality in nonlinear type-III thermoelasticity (GNIII)

Authors: Kovalev V. A., Radaev Y. N.

The present paper is devoted to formulations of constitutive equations for the non-linear Green–Naghdi type-III thermoelastic continuum consistent with the principle of thermodynamic (or thermomechanical) orthogonality.

Calculation plainly loaded geometrically nonlinear designs on the basis of mixed FEM with tenzorno-vector approximation requires sizes

Authors: Gureeva N. A.

The algorithm of reception on a step of loading designs matrixes of deformation of a volume final element with cross-section section in the form of any quadrangle with central unknown persons in the form of increments of movings and increments of deformations is stated in mixed formulation FEM. 

The asymptotic separation of variables in thermoelastic problem for anisotropic layer with inhomogeneous boundary conditions

Authors: Vestyak V. A., Zemskov A. V., Fedorov I. A.

 A method for resolving a thermoelasticity problem with inhomogeneous boundary conditions is presented. Boundary conditions represent uneven surface heating of the layer. An asymptotic procedure for separation of variables based on introduction of additional dimensional scales is used. With an additional assumption that the unevenness of the heating is small enough this procedure makes it possible to obtain the solution. The method is shown for periodic heating case.