43 research outputs found

    Modeling of radiative - conductive heat transfer in compositing materials

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    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

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    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

    No full text
    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.</jats:p

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

    No full text
    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

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    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

    Parametric and topology optimization of load bearing elements of aircraft fuselage structure

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    Abstract This paper presents the weight reduction of load bearing elements of aircraft DA-62 fuselage structure using parametric and topology optimizations methods. The structural analysis of rear part of aircraft fuselage in various load calculation conditions is performed. In the first step using parametric optimization of structure, allow to reduce its mass to 15.84 %. In addition using topology optimization of optimized structure by parametric modeling added mass reduction to 32.87% of total structural mass.</jats:p
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