Концентрація напружень та ефективні механічні характеристики пластинок із подвійно періодичними системами підкріплених отворів
DSpace at Ternopil State Ivan Puluj Technical University
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| Title |
Концентрація напружень та ефективні механічні характеристики пластинок із подвійно періодичними системами підкріплених отворів
Stress concentration and effective mechanical properties of plates with doubly periodic systems of enforced holes |
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| Creator |
Сулим, Георгій Теодорович
Пастернак, Ярослав Михайлович Куцик, С. Sulym, H. Pasternak, Ia. Kutsyk, S. |
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| Subject |
отвір
підкріплення накладка анізотропія подвійна періодичність hole enforcement overlay anisotropy doubly periodic 539.3 |
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| Description |
Використовуючи модифікацію методу граничних елементів, розглянуто подвійно періодичні системи отворів довільної форми із тонкими замкненими та розімкненими накладками. Обчислено концентрацію напружень та ефективні механічні характеристики таких композицій для різних відстаней між круговими отворами, відносних жорсткостей накладки та характеристик анізотропії матеріалу матриці.
Modern high-tech devices and machines are designed using mainly composite materials, since the latter are lightweight and provide desired rigidity and durability. A lot of attention is paid to the usage of perforated plates, in which edges of the holes are enforced by thin overlays. Therefore, this study is concerned with the analysis of doubly periodic sets of enforced holes. Based on the previously developed boundary element technique for doubly periodic problems and models of thin overlays, the efficient approach is developed for studying effective properties and stress concentration in perforated plates with enforced holes. The enforcements can be both closed and opened. First an infinite plate with doubly periodic fully enforced holes is considered. With the increase of the relative rigidity of an overlay, effective elastic moduli of the perforated plate expectedly increase. The smaller is the distance between holes the higher is the increase in effective elastic moduli. It is clear, that in the case of holes without enforcement (or an overlay of a very small rigidity) the closer are the holes, the lower are effective properties of the plate. For an anisotropic plate with holes the increase in rigidity of isotropic overlays gives different change in elastic moduli in different directions. The growth of the effective modulus in a direction perpendicular to fibers is the highest. The thinner is an overlay the more evident is an influence of its bending not only on the effective properties of the composite, but also on the maximal Mises stress in it. In particular, local maxima of Mises stress increases with the decrease of the thickness of enforcements. With the increase in the relative rigidity of overlays the longitudinal force and bending moment in each overlay also increase. The higher is the distance between holes the higher are the force and bending moment. This behavior should be accounted for during the design of perforated composite plates. Also the plate with a doubly periodic set of holes with a square lattice is considered. The edge of each hole is conditionally divided into six symmetric and identical parts, three of which are enforced with overlays. For the considered geometrical configuration of the opened reinforcements one of the effective moduli practically does not change with an increase in the rigidity of overlays. At the same time this increase significantly influences another elastic modulus and also effective shear modulus. This behavior is explained by the fact that selected arrangement of overlays “works” for tension/compression in one direction better than in other. Therefore, the usage of opened overlays allows changing effective properties of the perforated plate in the given direction, thus, establishing the desired anisotropy of the material. The numerical data obtained using proposed boundary element approach was verified by the commercial finite element software. Relative deviation of both approaches did not exceed 3 %. However, the advantages of the proposed approach are obvious, since it requires only boundary mesh, and no periodic boundary conditions are required to imposed, as they are already incorporated in the boundary integral equations used. |
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| Date |
2012
2013-06-27T09:27:25Z 2013-06-27T09:27:25Z 2012-06-27 |
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| Type |
Article
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| Identifier |
Сулим Г. Концентрація напружень та ефективні механічні характеристики пластинок із подвійно періодичними системами підкріплених отворів / Сулим Г., Пастернак Я., Куцик С. // Вісник ТНТУ. — 2012. — Том 67. — № 3. — С.7-16. — (механіка та матеріалознавство).
1727-7108 http://elartu.tntu.edu.ua/handle/123456789/2374 |
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| Language |
uk
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| Rights |
© „Вісник Тернопільського національного технічного університету“
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| Coverage |
Тернопіль, Україна
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| Publisher |
Тернопільський національний технічний університет ім. Івана Пулюя
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