Modeling of radiative - conductive heat transfer in compositing materials

A layer of composite material is investigated, which is heated one-sidedly with one-dimensional energy transfer accounting for thermal conductivity and radiation. A mathematical model is suggested for non-stationary coefficient thermophysical problem under radiative-conductive heat transfer in a material layer. Temperature dependencies of thermal capacity and thermal conductivity coefficient of composite radio-transparent material have been determined through numerical modeling by solving the coefficient reverse problem of thermal conductivity

Simulation of the curing of composite materials using microwave radiation with control of individual magnetrons

The traditional approach to the organization of the technological process of curing a binder polymer using microwave radiation is to rotate a workpiece around one axes in order to reduce the non-uniformity of its heating. Nevertheless, using this technical solution might lead to considerable difficulties when rotating larger workpieces, creating desired pressure on their surfaces and diagnosing the process. The approach suggesting that the workpiece itself remains stationary while the uniformity of its heating is achieved by creating a traveling electromagnetic wave in the operating area is to be considered a more promising direction in the development of curing technology. However, creating such a wave would require constructing a new and rather complex scheme for individual control of magnetrons, the theory of which has not been developed yet. The present work offers such a scheme of individual control and shows that using it allows to reduce the non-uniformity of the temperature field in a workpiece made of a polymer composite material with the maximum deviation of no more than 60 K, whereas the level of non-uniformity in the central part of the workpiece is not higher than 21 K

Simulation of the curing of composite materials using microwave radiation with control of individual magnetrons

The traditional approach to the organization of the technological process of curing a binder polymer using microwave radiation is to rotate a workpiece around one axes in order to reduce the non-uniformity of its heating. Nevertheless, using this technical solution might lead to considerable difficulties when rotating larger workpieces, creating desired pressure on their surfaces and diagnosing the process. The approach suggesting that the workpiece itself remains stationary while the uniformity of its heating is achieved by creating a traveling electromagnetic wave in the operating area is to be considered a more promising direction in the development of curing technology. However, creating such a wave would require constructing a new and rather complex scheme for individual control of magnetrons, the theory of which has not been developed yet. The present work offers such a scheme of individual control and shows that using it allows to reduce the non-uniformity of the temperature field in a workpiece made of a polymer composite material with the maximum deviation of no more than 60 K, whereas the level of non-uniformity in the central part of the workpiece is not higher than 21 K

Comparative analysis of methods for calculating the physico-mechanical characteristics of multi-layered composite materials

The paper presents a comparative analysis of methods and results of calculating the physical and mechanical characteristics of single-layered and multi-layered polymer composite materials (PCM). The object of the study is a polymer composite which consists of epoxy binder and carbon fiber reinforcements. The principle of multiscale modelling is applied to determine the physical and mechanical characteristics of the composite. Within the framework of this study, a representative volume element (RVE), the structure of which corresponds the characteristics of real materials, is used. The initial data for the calculation in this case are physical and mechanical characteristics of anisotropic fibers (carbon fabric) and an isotropic binder, as well as the geometric model of the RVE. As a result of the calculation, the effective characteristics of a quasi-homogeneous anisotropic material suitable for numerical analysis of the composite structures are determined. A comparison of the results of determining the physical and mechanical characteristics of the polymer composite using ANSYS Material Designer and MSC Digimat software packages for various size of RVE model is carried out and ANSYS Workbench software is also used to perform the stress-strain conditions of RVE model to determine the physico-mechanical characteristics of polymer composites

MODELLING OF HEAT EXCHANGE IN FLEXIBLE CONDUCTORS OF HALOGEN LAMPS OF THERMAL TEST FACILITY

Current work is dedicated to the evaluation of the possibility of safety use of serial halogen lamps for high power radiating heating test facilities with active cooling of the bulbs. Complex modeling of electrical and thermal processes occurring at various (standard, forced and extreme) facility operation modes has been carried out. The temperature values in the individual elements of the lamp supply system are obtained. A variant of the booth design, which provides the cooling of flexible wires and bus lines by the air flow, is rational from the point of safety and ensuring long-term uninterrupted operation view

MIRROR SPACE ANTENNA REFLECTOR MADE OF COMPOSITE MATERIALS CONSTRUCTIVE APPEARANCE DETERMINATION

This article describes search studies of optimal design and technological solutions for the ultralight mirror space antenna reflectors made of CFRP. The studies included finite element modeling of the reflector temperature and stress-strain state in the geostationary orbit. As a result of comparing the results of a number reflector variants modeling, a design was chosen, with minimal values of temperature displacements and linear densit

NANOSATELLITE BODY COMPOSITE MATERIAL THERMAL CONDUCTIVITY DETERMINATION COMPUTATIONAL AND THEORETICAL METHOD

In this paper, we present a technique for determining the thermal conductivity of an anisotropic composite material (CM) of a body of nanosatellite on a contact heating installation. A description is given of the technique of a thermal physics experiment with CM samples in the form of thin-walled plates, which were parts of the body of nanosatellite