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This work investigates the effect of carbon nanomodification on the residual stress-strain state (SSS) after molding. One of the ways to reduce residual stresses and deformities is nanomodification. The main objective was to determine the degree of influence of the nanomodification parameters on the residual SSS. Within the framework of this study, 4 slabs were made. Two slabs are made of a conventional binder with laying [010/9010] and [010/4510] and two slabs of a modified binding material with the same layer structure. For the fabricated plates, deflections were measured on each of the four sides, during which residual strains were obtained in the panels of nanomodified carbon fiber for the considered layings with and without modified binding material. To analyze the residual stress-strain state, a numerical and analytical calculation was performed. The numerical calculation was carried out by means of the finite element method for the case when the slab is fixed at the point of the geometric center, with no power load, and the temperature load is a difference of 100 °C. An analytical calculation was carried out for the case when the slab is free from fastening and external power load, and the temperature load is a difference of 100°C. During the study, variants of the physicomechanical properties of the monolayer were obtained using the Digimat software and the Mori-Tanaka averaging method. The results obtained by analytical and numerical methods have a good correlation between each other, and in the course of comparison with the experiment, a method for calculating the characteristics of the monolayer that was closest to the experimental result was determined. On the basis of the obtained results, conclusions were made on the possibility of reducing residual SSS and deformation in structures with asymmetric reinforcement schemes using a matrix containing carbon nanoparticles. [ABSTRACT FROM AUTHOR]

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Currently, methods of three-dimensional printing of products from polymer, metal and ceramic materials are widely used. Layer-by-layer synthesis technologies make it possible to obtain high-quality products with sufficiently high mechanical characteristics close to those realized using traditional technological processes. A related problem is solved, including calculating the temperature in the product and the operation area surrounding it in a flat setting based on two different approaches. For a layer-by-layer extensible body, the unsteady heat conduction problem is stated. At each step, the height of the computational region increases due to the filling of a new layer of powder. One time step of the calculation is determined by the interval between two consecutive passes of the laser. The temperature distribution found at each step is used as the initial conditions for the calculations at the next step. The temperature field obtained as a result of solving the problem that is implemented in the product in question with a step of 1000 (after applying and melting 1000 layers) is further compared with the solution of the quasi-stationary problem for the finite dimensions product. Using the example of the simple geometry taken, it is shown that a quasi-stationary solution can provide a satisfactory estimate of the macroscopic thermal state of the growing product. [ABSTRACT FROM AUTHOR]

Copyright of Periódico Tchê Química is the property of Grupo Tche Quimica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Intensive development of equipment contributes to a significant impact on the high level of competitiveness of new samples, improving technologies, and promise of enshrined ideas as well as resource intensity and time of their implementation. The relevance of the scientific paper lies in the fact that in the process of designing drive systems for guiding aviation equipment, one of the important elements is taking into account the limitations on the power source energy storage. The purpose of the scientific paper is to develop a mathematical model of energy efficiency of mechatronic modules and power sources for prospective mobile objects. An integrated approach is used to study the influence of structures and elements of storage devices on the characteristics of power sources in the interest of finding the ways to increase the energy efficiency of the entire drive system for guiding mechatronic modules of aviation systems in general. It has been determined that in order to reduce the weight-size parameters of the power supply source, the stabilizer in the power section, as a rule, is not set. It has been found out that power and information sections of drive systems differ from each other in terms of the stability of the energy coordinates. And stabilized parameters (potential, current) are necessary only for the information channel. With the help of analytical dependencies, the main parameters of the primary source were evaluated depending on the efficiency of the consumer, efficiency of the stabilizer and efficiency of the secondary power source. A method to study the influence of elements of the energy (power) channel on the output power of the power source the mechatronic modules for prospective aviation mobile objects (autonomous aviation drives, guided missiles, guided parachute systems) is being developed. [ABSTRACT FROM AUTHOR]

Copyright of Periódico Tchê Química is the property of Grupo Tche Quimica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Periódico Tchê Química is the property of Grupo Tche Quimica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

On the basis of mathematic simulation, the problem of optimizing the energy storage and the massdimensional parameters of the mechatronic modules of aviation equipment is solved by synthesizing the structure and analyzing the characteristics of various power supplies, a generalized model of the power supply source developed for various power supply sources of the drive control systems is given, a theoretical review of the currently used chemical current sources is carried out, the comparison of sets of external characteristics of capacitive and pneumatic storage media with a set of external characteristics of the chemical current source. The generalized model of the aircraft power supply source, described in the article, can be used in the design of highly efficient mechatronic modules of control systems for autonomous mobile objects of a new generation. [ABSTRACT FROM AUTHOR]

An analytic solution of a Stefan-type problem with one non-stationary moving boundary of phase transformations simulating linear heat transfer in an inhomogeneous medium is considered. In simulating the heat and mass transfer process, the generalized heat equation is used, taking into account the finite rate of heat distribution Cq . This formulation of the problem adequately describes the thermal state of the materials during their high-temperature heating, where the pressure is taken into account because of the low rate of filtration of the pyrolysis gases. It is assumed that the braking pressure should exceed the ambient pressure by the hydraulic resistance of the porous residue. Comparison of numerical and analytical solutions is performed, both. [ABSTRACT FROM AUTHOR]

Copyright of Periódico Tchê Química is the property of Grupo Tche Quimica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)