The article discusses the stress-strain state of a reinforced concrete floating pontoon caused by critical stresses before its destruction. The investigation was motivated by the destruction of the pontoon, which occurred under extreme wind and wave impacts. A method for determining wind, wave and current loads is presented. The investigation was carried out on finite element computer models. As a result of the investigation, critical efforts and stresses were obtained, causing the destruction of the pontoon. The main conclusion of the conducted investigation is the possibility of using a floating reinforced concrete pontoon in waters with limited values of wind, wave effects and loads from the current.
CONCLUSIONSi. Investigations show the possibility of the practical use of an expansion joint on a base of sheet metal and rubber in reinforced-concrete pipelines. However, the butt joint in the form of a steel plate covered by sheet rubber is short-lived as a consequence of its wear.2. An expansion joint with a special lining, for example, of polyethylene, between the metal and rubber is simple to manufacture, reliable in service, and can be recommended for use in reinforced-concrete pipelines. LITERATURE CITED i. O. V. Mikhailov, V. N. Zaitsev, and V. V. Lgalov, "Use of glass-fabic stretch material for a flexible joint of precast pipe sections," Gidrotekh. Stroit., No. ii (1986).
Individual suggestions on using statistical methods of analysis and calculation of various environmental influencing factors and stress---strain states of structures are known in the practice of design and evaluation of the reliability of hydraulic structures subjected to wave action. We can cite numerous works, including one of the latest publications in this area [1] concerning a determination of the reliability of reinforced-concrete revetments of earth slopes by dynamic tests of individual slabs and subsequent generalization of the results obtained by statistical analysis. However, the latter method of a probabilistic evaluation of the acting factors can by used only for determining the amount of repair and restoration works on existing objects. Different principles in selecting the criteria of wave actions are required in the case of new construction, limit-state calculations, and prediction of probable overloads and disturbances of the continuity of structures being planned.To provide sufficient strength and deformation characteristics of the elements of structures, it is first of all necessary to use scientifically founded initial data for conditions of real wind waves, which makes it possible to use their differentiated consideration in various cases of wave action.The results of theoretical and experimental investigation of the frequency of the characteristics of wind waves in their systems or in storms on water areas have found wide practical use when solving the aforementioned problems. In particular, the random distribution of the height of waves are included in the standards for determining loads an effects on hydraulic structures [2]. Other characteristics (length, period, and velocity of waves) are described by their own stochastic functions [3]. It follows from the given literature that real waves under the effect of wind with respect to the relationships and distributions of the geometric and kinematic and, consequently, also dynamic parameters substantially differ from regular monochromatic waves of the swell type or other forms caused by generators of solitary or periodic action.Therefore, it was noted earlier [4] that the specific characteristics of the formation of storm conditions affects not only the character of the temporal variation but also the instantaneous occurrences of various actions of irregular waves on hydraulic structures. In contrast to the sometimes existing notion, hydraulic processes of a wind-wave genesis in the zone of obstacles are due not to individual local positions of the free water surface and pressure gradients from individual waves but are mainly integral manifestations of systems of adjacent and successive waves regulating the general level, turbulent, and mass-transfer regimes in the corresponding zones of influence.At the same time, the seeming chaotic character of various irregular wind-wave processes is completely validly determined by functions having scientific and practical applicability.Let us examine the ease of the most distinct manifestation of the gro...
This article presents a problem of researching of the intense deformed state of units of metal structures for the purpose of optimization this units in the case of the variant design of buildings and structures with a metal frame. There are examples of results which were get after laboratory experiment and computer modeling the same unit. The laboratory experiment was made on a optically-sensitive model, in other words, by photo elasticity method, which visualizes the difference of the main tension. And the same picture was get after the ANSYS computer model was designed. It is noted that in the traditional approach the designer develops a limited number of options, the consideration of which does not guarantee the closeness of the final result to the optimum. The authors indicate that the problem of development of new or improvement of existing methods of optimization of design decisions of structures is relevant, and its solution is one of directions of perfection of computer-aided design, which require verification of accuracy. One way to test the accuracy of a polarization-optical method, which is based on the property of most of the isotropic transparent material to acquire under the action of mechanical stresses (deformations) the ability to double refraction (optical anisotropy). In the study of spatial computer models developed in ANSYS, the authors obtained isopole of the principal stress distribution in the analyzed section of the model. The analysis of the received results of researches of stress state of the rigid attachment of the farm to the column, the experimental method of photoelastic analysis and obtained on a computer model in ANSYS revealed a clear convergence of the results.
Multi-story frame buildings in precast concrete are one of the main types of buildings being built in the country. The article considers and analyzes the results of the numerical calculation of the structural system of a multi-story frame building, made using the LIRA-SAPR software package. It has been shown that with a semi-rigid assembly of the crossbars with columns it is necessary and possible to simulate the compliance of the joints. The ratio of bending moments in spans and on supports in the crossbars of the calculation scheme depends on the coefficient of compliance (rigidity) of the joints. In its turn, the compliance of semi-rigid joints is a complex quantity, determined by the compliance of the structural elements of the joints, namely: the compliance of the embedded parts in the joined elements of the frame, the compliance of the connecting cover plate, the compliance of the welds for the connecting cover plate, as well as the compliance of the seam between the crossbar and a column filled with cement-sand mortar. An algorithm for determining the compliance of structural elements of a semi-rigid joint is given.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.