Registration Number
0224U033334,
(0124U002858)
, R & D reports
Title
Identification of the thermomechanical parameters of nonhomogeneous composite materials and protective coatings
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Аналіз теплового прогину поверхні напівобмеженого композиту із багатошаровим покриттям
Head
Yurii V. Tokovyi, Доктор фізико-математичних наук
Registration Date
25-12-2024
Organization
Institute of Applied Problems of Mechanics and Mathematics named after Ya. S. Pidstryhach of the National Academy of Sciences of Ukraine
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The project is aimed at the development of efficient theoretical-experimental methods of the identification of effective parameters of nonhomogeneous composite materials (the profiles of macroscopic material modules depending on irregular micro-structure, the presence of defects, the boundary irregularity, thin interlayers, and protective coatings), as well as unknown parameters of the thermal and force loadings of structure members implemented by using the nonhomogeneous composite materials. А technique for solving the problems on the identification of the thermal and thermostressed states in multilayer, functionally graded, and thermosensitive solids will be presented under the lack of information about the thermal loading on some segments of the plane surfaces and the supplementary data about the stress-strain state (thermal stresses, strains, or displacements) on the remaining parts of the surface. The obtained theoretical results will be verified by experimental testing.
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Within the framework of the axisymmetric thermoelasticity problem of local heating by a heat flux of the surface of a homogeneous medium with a multilayer insulating coating, the influence of the geometric and physical properties of the coating layers on the thermal deflections of a previously flat body surface was investigated. Two mathematical models of the coating were considered. When constructing the first model, the homogenization method with microlocal parameters was used. The second mathematical model is based on the classical approach, in which each coating layer is considered separately. The analysis of the solutions obtained by the proposed approaches was based on the comparison of the value of the parameter describing the degree of thermal curvature of the heating surface. It is shown that for a relatively large number of representative cells, the values obtained in the two mathematical models differ only slightly from each other. If the coefficient of linear thermal expansion of the heat insulator used is much smaller than the corresponding coefficient for the substrate, agreement is achieved by 2-3% even for a relatively small number of representation cells. It should be noted that for a certain number of cells, the difference between the solutions depends mainly on the ratio between the thickness of the representative cell and the characteristic linear size of the heating area. It is shown that the proposed homogenization method correctly describes the properties of not only a multilayer coating with a periodic structure, but also the properties of a coating with a slowly graded structure, and can be effectively used to analyze problems of the theory of elasticity that are difficult to solve in the classical approach, in particular contact problems associated with heat generation.
Product Description
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Kalyniak Bohdan M.
Shevchuk Viktor A.
Yuzviak Mykola Yo.
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2024-12-25
