Vol 20, No 4 (2019)

Development of the optimal structural arrangement for a reflector with the aim to improve its mass and design is of importance due to the necessity to increase areal density and decrease rigidity of the modern space antennas vehicles. Currently, CAE-systems allow to design reflectors using both traditional methods, for example, parametric optimization, and methods which are innovative in this field, such as topology optimization. The paper compares two methods of the structural arrangement design for a thin dimensionally stable reflector operating as part of a geostationary spacecraft: parametric and topology optimization. The algorithms of the structural arrangement development which include the statement of the optimization problem, geometry design and a number of check analyses are presented. A number of structural of a space reflector design under the action of loads at the stage of launch, temperature gradients at the exploitation conditions and modal analysis is performed. The designed reflectors are compared. The studies performed allowed us to develop the optimal structural arrangement for a space reflector using the parametric and topology optimization. The optimal structural arrangement for a space reflector using the optimization could be produced surface figure error (estimated in RMS) with respect to the theoretical paraboloid.

In the Soviet Union, a unique worldwide industry was created for the serial production of forging equipment. Currently, even these machines that have served their design life are in working or maintainable condition. This has led to the fact that there is now a large market for the secondary sale of such machines, including in the countries of Southeast Asia and India. However, with the secondary sale of such equipment, some inevitable damage builds up in the basic parts. In addition, the first copies of such models, put up for secondary sale, were produced at a time when non-destructive testing methods were not developed. Some defects could be undetected. When buying a machine dismantle, transport, install and test. Cases were recorded when defects were strained during installation and testing in the base parts, which made it difficult or impossible to use such equipment. Sometimes this type of equipment (during modernization) is used to carry out technological operations that require more power than previously declared. Therefore, when buying/selling (or upgrading), it is necessary to draw up cards of permissible defects, which, when superimposed on the cards of the detected defects, will allow to reject/determine the remaining life/limit the technological strength of the crank machine so that defects during further operation are not affectted and do not lead to emergency situation. The methodology for determining the permissible parameters of subsurface elliptical cracks is shown on the example of a press bed KD2130 (BZMP).

The article discusses the comparative analysis of software (MS Excel, Mathcad and Matlab) for the study of statistical methods of product quality control necessary for the training of future specialists in the field of product quality. The choice is determined by the presence of this software in the educational institution. Statistical methods of product quality control are mandatory elements of modern quality management systems implemented at Russian enterprises, the competitiveness of which largely depends on the ability of the company's personnel to apply these methods in practice at all stages of the product life cycle. The analysis of product quality begins with the construction of a histogram to identify avoidable and irremediable defects and compare it with the normal distribution curve. The process of forming the shape of the normal distribution curve can be traced in the construction of control maps based on a scatter plot of the sample. The next step is the construction of dot diagrams, on the basis of which control maps are built (in our case - the control map of Shewhart). The final step in training is the construction of Pareto diagrams to identify the causes of defects with ABC analysis. The authors conducted a comparative analysis of software products MS Excel, Mathcad and Matlab for the implementation of basic statistical methods of product quality control. For training it is proposed to choose MS Excel because of the availability of the Data Analysis package, free analogues that are widely used in enterprises, the ability to store the original data and use them in other programs (data import).