**UDC **624.014

**DOI**: 10.31521/2313-092X/2018-4(100)-19

**O. V. Boichuk**

**O. V. Tsepurit**

**I. I. Hilko**

**S. I. Bohdanov**

*The paper shows the main approaches to the method of calculating the strength, reliability and stability of the frame elements of metal structural arches of variable cross section. The calculation is performed in the design of optimal arched structures, which consists in designing the structure so that in all sections of the structural element of the arch the reliability was specified, and the mass of the arch structure was as minimal as possible.*

*The use of light arches with a given reliability provides savings of metal and reducing the cost of construction and determines the prospects of the use of such structures in buildings and agricultural structures.*

*The maximum reduction in the cost of prefabricated light metal structures and work related to their construction is a priority at the current stage of development of the construction industry in Ukraine. Simultaneously with the reduction in the cost of construction during the design, it is necessary to remember about ensuring their sufficient durability and reliability. One of the effective means of solving this problem is the introduction of methods of the theory of reliability, which allow more reasonably normalize the design parameters of the structure and loads on a probabilistic basis. More important is the transition to a probabilistic calculation and estimation of the supporting capacity of structures according to the main technical criterion – the probability of failure of the structure.*

*Issues related to optimal design are of particular interest, when the probabilistic nature of the work of the structure is taken into account. In this case, one of the most important characteristics is the reliability of the structure, as well as the strains and deformation that occur in the structure under various external influences. The result of the calculation should be the answer to the question of whether the structure will be able to serve reliably enough during the service life. Knowledge of the values of strains and deformations is ultimately necessary only in order to make a judgment about the reliability and durability of the design of the arches. Therefore, the task is set: to design the structure in such a way that in all sections of the structural element of the arch the reliability is given, and the mass of the structure of the arch is minimal. The article deals with the problem of finding the law of distribution of material along the axis of the arch design. By analogy with the fact that in the deterministic formulation of the problem, the case of equal tension is considered the most suitable case of strains distribution over the flight of the arch, we assume that in the probabilistic statement the optimal case of stress distribution over the span is also the case of equal tension.*

**Keywords**: flexible wall, steel frame, cross-sectional area of the frame, length of the intersection of the frame, safety factor, reliability of the steel structure, stability of the.

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Ключевое название (Key title):

Vìsnik agrarnoï nauki Pričornomor'â (Online)

Сокращенное ключевое название (Abbreviated key title):

Vìsn. agrar. nauki Pričornomor'â (Online)

Параллельное название (Parallel title):

Ukrainian Black Sea region agrarian science