Vol 7, No 1 (2008)

The paper deals with choosing the form and centre of inertia position of a space vehicle with a view to eliminating resonance which occurs during unguided descent in the rarefied atmosphere of Mars. Blunted small-elongation space vehicles consisting of a conical part and a spherical one are discussed. The criterion of absence of resonance is obtained analytically with the help of Newton’s shock theory. Practical recommendations on choosing the form of a space vehicle are given to eliminate the possibility of resonance arising.

The paper deals with the propulsion of a hypersonic accelerator aircraft acting as the first stage of a two-stage aerospace system. Optimal and approximately optimal angle of attack programmes are defined on condition that fuel consumption is minimal. The impact of the trajectory inclination finite angle magnitude on the pattern of control programmes and mechanical trajectories is analysed.

The paper deals with the identification of a linear mathematical model of gas turbine engines by the results of testing using the simplest Huber method with regard to additional information on engine parameter measurement error and possible magnitudes of parameter variations characterizing unit operation.

The second part of the article presents the results of solving some applied problems of flights of space vehicles with low-thrust engines.

A vibrational model of a three- layer honeycomb sandwich with partial skin peeling has been developed. The impact of peeling amount on the natural frequency of vibration and the amplitude-frequency characteristic has been analysed. Comparative analysis of design values and experimentally obtained results has been made.

The paper presents the results of experimental investigations concerning the choice of materials for making current-conducting and frame elements of inductors for pulse magnetic forming. Various kinds of inductor construction are considered, their efficiency as to the amount of deformation of a tubular blank is determined. Recommendations on the designing of operating inductor systems for production conditions are given.

The paper deals with the problem of constructing models of circular route networks tasking account of the specificity of municipal passenger transport.

A procedure of thin-walled multistringer torsion box design in view of geometrical non-linearity is proposed. Initial non-linear relations are linearized by the successive loading method. Solving equations are obtained by using the Lagrange principle; these are presented in the form of a boundary problem for a system of ordinary linear differential equations.

The paper presents the results of investigations related to the realization of efficient technology of magnetic pulse working. Higher process efficiency is due to the optimization of energy transfer in a discharge circuit and the transformation of pulse field pressure into deformation work and blank kinetic energy. The basic expressions that make it possible to determine the amount of losses of energy stored in the system’s capacitors as it is transformed into blank deformation work.

The paper presents a method of calculating electrical and operating characteristics of any number of parallel EASMFs due to the reduction of furnace circuit resistances to high-voltage buses and the use of the method of superposition. It is shown that in order to determine the combined operating current of parallel EASMFs at the method of adding series-parallel resistances of a group of EASMFs and the method of EASSF operating currents according to the cosine law can be used. It has been found that determining the combined operating current of parallel EASMFs by simple adding of operating currents leads to insignificant errors.

The paper proposes an iteration method of correction function superposition for initial estimate in the form of hyperbolic-trigonometric series by two coordinates,which as they are superimposed,mutually compensate the misclosures they generate in boundary conditions. The misclosures decrease as the number of iterations grows and a solution can be obtained with any degree of accuracy. Numerical results of calculating deflections and bending moments of a Reissner cantilever plate under uniform loading are presented. Comparison with the classical theory is given.

The paper deals with calculating the error of non-linearity of positional characteristics of a displacement transducer on multicomponent optronic structures.

The paper deals with the problem of assessing the quality of production processes and mounting of technical systems considering the presence of latent consumer. Procedures of assessing the quality of life cycle processes are specified. Tools for analyzing requirements from the standpoint of the process owner are formed.

The paper deals with knowledge formation in the expert system of aid to the aircraft crew for the subject area «Aircraft crew actions in emergency situations». A combined hierarchical model of knowledge formation is proposed, based on object approach, production rules and Petri network structure. The knowledge formation developed makes it possible to for man integral model of the subject area for the analysis of database and knowledge conclusion mechanism.

The paper present a model of forming a set of a measurable multitude of parameters for assessing the technical condition of an airborne equipment complex (AEC) of aircraft in the context of a diagnostic control system represented by a network which incorporates generatices as basic images. A set of axioms is proposed for forming the assessment of generatrix condition on the basis of indication vector, the generatrices presenting theAEC system being diagnosed. The architecture of a system of diagnostic control of the maintenance object condition in the form of a network whose functioning is connected with the system of axioms introduced is also proposed.

The concept of algorithm is analysed. A method of choosing algorithms on the basis of dispersion analysis is proposed and considered as a method of assessing metrological characteristics of algorithms of the degree of object correspondence to functional purpose. Various algorithms are examined.

The paper deals with the question automatization of models of basic business processes of press forging design and technological preparation. Ways of reducing the time of technological preparation of production due to the use of computer-aided document turnover in production processes are shown. The use of a resource-oriented approach for the modeling of industrial subject area is proposed, the required functional model decomposition indicator is defined on the basis of document status, data model patterns are specified.

The paper deals with forms and methods of involving engineering workers in creative work, in rationalization and invention movement at machine building enterprises of the Middle Volga Region in 1970s.