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- STRUCTURAL MECHANICS
- Experimental-Theoretical Studies of Static-Dynamic Deformation of a Spatial Reinforced Concrete Frame with Complex-Stressed Beams of Solid and Composite Cross-Sections
- UDC 624.012.45

**Alexey I. DEM'YANOV**, e-mail: speccompany@gmail.com

**Svetlana A. ALKADI**, e-mail: fortina2008@mail.ru

Southwest State University, ul. 50 let Oktyabrya, 94, Kursk 305040, Russian Federation

**Abstract**. The results of the study of static-dynamic deformation of a fragment of a spatial reinforced concrete frame with constructions of solid and composite beams are given. The proposed analytical model for the evaluation of the strength of such reinforced concrete structures in bending with torsion is substantiated. Tests of the reinforced concrete frame with beams working on bending with torsion confirmed the working assumptions formulated with reference to the development of the calculation model. The proposed design scheme is constructed according to the block principle with the use of the model of the stress-strain state of the normal section passing through the end of the spatial crack and the model of the stress-strain state of the spatial section formed by a spiral-shaped crack. On this basis, solving equations have been obtained, which make it possible to find all the important parameters in a complex stress-reinforced concrete element when bending with torsion. In this case, the equations of equilibrium and deformation for the problem under consideration are recorded with respect to the transverse and longitudinal vertical planes. This greatly simplifies the calculation formulas and makes it possible to take into account the axial forces in the transverse reinforcement located at the side faces of the element in relation to the normal and spatial cross-section. The experimental confirmation of the proposed in the calculation model of the correction of longitudinal stresses with the help of coefficients is obtained. This makes it possible to significantly clarify the stress-strain state of the compressed zone over a dangerous spatial crack.

**Key words**: static-dynamic deformation, experimental research, reinforced concrete component, bending with torsion, calculation models, beyond design impacts. - REFERENCES

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