Engineering Method of Calculation of Beam Structures Inclined Sections Based on the Fatigue Fracture Model

The aim of this paper is the creation of engineering method of inclined sections of beam structures calculation under the action of cyclic loads, that takes into account the concrete and reinforcement fatigue strength. Methods of research are key expressions determining the endurance limits of concrete, longitudinal reinforcement, and anchoring longitudinal reinforcement, which based on the real physical and calculated models of beam structures inclined sections work. The results of work links with the creation of expressions determining the boundary forces that can be carried out by structural element under the action of cyclic loading. Scientific novelty and practical significance is that presented engineering method takes into account the change of stress-strain state of span reinforced concrete structures at their repeated load, as well as, a change of strength properties of the concrete, reinforcement and their clutch at the moment t, and can be used on all range of strength characteristics of materials change- from low-cycle repeated, to repeated cycle load.