Abstract
The paper considers the stress-strain state of a reinforced concrete beam, as a bimodular material, under the action of an impact. The behavior of bimodular concretes with different moduli of elasticity in tension and compression has not been studied enough. At the same time, taking into account the bimodularity of concrete makes it possible to design a more economical structure, especially for dynamic load. In this article, the impact is considered as an absolutely plastic impact of an absolutely rigid body on an elastic system. The stress state is investigated for beams of rectangular, T-section and I-sections, and is compared with and without the bimodularity of reinforced concrete. The analysis of the dependence of the stress state on the shape, cross-sectional dimensions, and the location of reinforcing bars in the compressed and tensioned zones was carried out for lightweight concrete (Et < Ec) and for heavy concrete (Et > Ec) under the action of shock load with and without regard to the mass of the beam. The numerical study shows that taking into account the mass of the beam upon impact significantly decreases the magnitude of the normal stresses in both the tensioned and compressed zones. Beams of rectangular cross-section have the highest load-bearing capacity when the cross-section height is equal for both light and heavy concrete. An increase in the size of the flange of the I-beam in the stretched zone leads to a sharp decrease in normal tensile stresses and a slight increase in normal compressive stresses. The proposed engineering method makes it possible to numerically study the effect on the stress-strain state of a beam under the action of a concentrated impact of various geometric characteristics of the cross-section, bimodularity of the material, size, number and location of reinforcement.
Highlights
The importance of theoretical and experimental research on the behavior of structures subjected to various types of shock impacts has attracted the attention of many scientists and practitioners to the development of methods for calculating strength and stiffness and conducting experiments to determine the degree of reliability of structures.Buildings 2020, 10, 248; doi:10.3390/buildings10120248 www.mdpi.com/journal/buildingsDynamic effects, impacts, are the most dangerous types of loading of buildings and structures (Lyapin A. et al [1])
In the example of a supported beam with various cross-sectional shapes, rectangle, I-beam and T-beam, the values of the maximum compressive and tensile dynamic normal stresses arising from the action of a falling load with a mass of MA = 100 kg from a height h = 4.00 cm to the middle of a reinforced beam made of a bimodular material were calculated
The results of the study showed that the strength of reinforced concrete beams under shock loads is affected by a wide range of both mechanical and geometric characteristics
Summary
The importance of theoretical and experimental research on the behavior of structures subjected to various types of shock impacts has attracted the attention of many scientists and practitioners to the development of methods for calculating strength and stiffness and conducting experiments to determine the degree of reliability of structures.Buildings 2020, 10, 248; doi:10.3390/buildings10120248 www.mdpi.com/journal/buildingsDynamic effects, impacts, are the most dangerous types of loading of buildings and structures (Lyapin A. et al [1]). The importance of theoretical and experimental research on the behavior of structures subjected to various types of shock impacts has attracted the attention of many scientists and practitioners to the development of methods for calculating strength and stiffness and conducting experiments to determine the degree of reliability of structures. The complexity of the calculations of structures for dynamic actions, accompanied by the solution of systems of partial differential equations, complicates the analysis of the stress-strain state (Beskopylny A. et al [2], He X-T. et al [3]). The fundamental foundations of wave processes during impact and methods for solving partial differential equations describing processes during impact are considered. An important part of the book is devoted to the description of the technique of the experimental study of shock and wave processes
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
